This document provides a review of state-of-the-art nonlinear inelastic analysis methods for steel structures. It discusses five different analysis methods ranging from simple to rigorous, including plastic-zone, quasi-plastic hinge, elastic-plastic hinge, notional-load hinge, and refined-plastic hinge analysis. It also summarizes several experimental studies on nonlinear behavior of steel frames. Finally, it addresses considerations for modeling, analysis, and design using nonlinear inelastic analysis methods. The goal is to review research enabling the use of these advanced analysis techniques directly for frame design.
Studies on reinforced hollow concrete block masonryeSAT Journals
Abstract Masonry may be defined as the assemblage of building units joined with the help of cementitious material or any accepted joining material to perform required function. It has its own reputation and performs multi-functions in load bearing structures such as- supporting loads, dividing spaces, thermal and acoustic insulation, weather and fire protection etc, but it has to be provided separately in framed structures. In present scenario, there is a great demand for construction of Multi-storied residential buildings in urban area because of needful requirements. Most of such buildings are constructed using RC-framed structure. On the other hand RC-framed structures are expensive and relatively difficult to construct because of the need for formwork. Masonry has a great benefit since it does not need form work. If moderate to High strength Engineered hollow concrete blocks are available, one can think of providing reinforcement through the core of such Hollow blocks. In this project an attempt has been made to obtain the load carrying capacity of Reinforced Hollow Concrete Block Masonry through experimental investigation by considering two different percentages of steels - for this totally four number of Reinforced hollow concrete block masonry prisms (RHCBM) using 12 mm diameter bar and six number of Reinforced hollow concrete block masonry prisms (RHCBM) using 8 mm diameter bar were casted and tested. Further, an attempt has been made to compare the experimental load carrying capacity with the conventional mechanics based approach used for analyzing short columns. There was a fairly good co-relation between the analysis and experiments. Key Words: Unreinforced Masonry, Reinforced Hollow Concrete Block Masonry.
Influence of micropolar lubricant on bearings performance a review(2)susheelpote
This review article summarizes research on the influence of micropolar lubricants on bearing performance. Micropolar lubricants account for the microstructural effects of additives and contaminants in lubricating oils. The article first introduces micropolar fluid theory, which generalizes the Navier-Stokes equations to include microrotation effects. It then reviews how micropolar theory has been applied to analyze the performance of various bearing configurations, including slider, thrust, step slider, and journal bearings. The performance metrics considered include load capacity, friction, flow, heat generation, and stability. Research has found micropolar lubricants can increase load capacity and reduce friction in many bearing types compared to classical Newtonian lubric
A study on plastic hinge formation in rc frame by nonlinear static analysiseSAT Journals
This document presents a study on plastic hinge formation in reinforced concrete (RC) frames under nonlinear static pushover analysis. A single-bay, single-story RC frame is modeled and analyzed using SAP2000 software. The order and location of plastic hinge formation is observed as the frame is subjected to incremental lateral loading. Four plastic hinges form in total. The sequence of hinge formation is found to control the deformation behavior of the frame. Understanding hinge formation and the gap between successive hinges forming provides better insight into the performance of the structure under earthquake ground motions.
Static Structural, Fatigue and Buckling Analysis of Jet Pipe Liner by Inducin...IRJET Journal
This document analyzes the static structural, fatigue, and buckling behavior of conventional and corrugated jet pipe liners through finite element analysis. A conventional liner model and optimized corrugated liner model were created and meshed. Static structural analysis found that the corrugated liner had lower deformation and similar von-Mises stresses to the conventional liner. Fatigue analysis determined the corrugated liner had a slightly lower fatigue life but still above the design target of 1 million cycles. Buckling analysis revealed the corrugated liner had a higher buckling load multiplier, indicating it is stiffer than the conventional liner against buckling. In conclusion, introducing corrugation improved the liner's buckling strength without negatively impacting other
The Comparison of Properties of Tinplates during Uniaxial and Biaxial Stresstheijes
The majority of thin steel sheets is used to make of food covers, cans, capsules and other products, which are produced by metal forming. Concerning considerable changes in production of tinplates and still higher requests on their properties there is requirement to use such methods on their evaluation, which are able to determine especially mechanical and plastic properties of sheets quickly and with the low costs. Following of present know-how there were developed new testing methods, which correspond more to steel sheets stress during technological treatment (concerning their stress-strain state). In the contribution we deal with the comparison of properties of tinplates during uniaxial tensile test and biaxial tensile test.
Based on the experimental and numerical studies performed by NIST an Alternative Load Path Analysis (ALPA) guideline is being developed by the Disproportionate Collapse Technical Committee to provide design, analysis and modeling methods for engineers in practice to reduce the vulnerability of steel and concrete structures to disproportionate collapse. This article presents a summary of chapter 3 of this guideline, titled Simplified Analysis to Predict Collapse Resistance. Chapter 3 focuses on simplified analysis methods that can be applied in form of spreadsheets or closed form solutions to predict the collapse capacity of steel and concrete buildings.
1) An experimental study was conducted to compare the compression behavior of normal strength concrete (NSC) and self-compacting concrete (SCC) intermediate columns.
2) Six column specimens with a cross-section of 125x125mm and a height of 1.5m were tested under axial loading. The columns varied in concrete type (NSC and SCC) and longitudinal reinforcement ratio (2.09%, 2.89%, 5.15%).
3) The results showed that as the reinforcement ratio increased, the ultimate load capacity increased and axial deformation decreased for both NSC and SCC columns. However, SCC columns exhibited higher ultimate loads and deformations than NSC columns for the same reinforcement ratio.
IRJET- Buckling Evaluation of a Plastic Bottle DesignIRJET Journal
This document presents research on evaluating the buckling of a plastic bottle design through finite element simulation. Researchers created a geometric model of a PET bottle in SolidWorks and imported it into ABAQUS for meshing and analysis. Static, buckling, and dynamic analyses were performed to determine maximum stress, buckling modes, and structural response under crushing loads. The bottle thickness was optimized to reduce weight while maintaining strength. Top load testing validated the model, showing a maximum vertical deflection of 59.2mm and maximum stress of 119MPa, below the yield point, confirming the design is safe. The study provides a method for optimizing plastic bottle structure through finite element analysis.
Studies on reinforced hollow concrete block masonryeSAT Journals
Abstract Masonry may be defined as the assemblage of building units joined with the help of cementitious material or any accepted joining material to perform required function. It has its own reputation and performs multi-functions in load bearing structures such as- supporting loads, dividing spaces, thermal and acoustic insulation, weather and fire protection etc, but it has to be provided separately in framed structures. In present scenario, there is a great demand for construction of Multi-storied residential buildings in urban area because of needful requirements. Most of such buildings are constructed using RC-framed structure. On the other hand RC-framed structures are expensive and relatively difficult to construct because of the need for formwork. Masonry has a great benefit since it does not need form work. If moderate to High strength Engineered hollow concrete blocks are available, one can think of providing reinforcement through the core of such Hollow blocks. In this project an attempt has been made to obtain the load carrying capacity of Reinforced Hollow Concrete Block Masonry through experimental investigation by considering two different percentages of steels - for this totally four number of Reinforced hollow concrete block masonry prisms (RHCBM) using 12 mm diameter bar and six number of Reinforced hollow concrete block masonry prisms (RHCBM) using 8 mm diameter bar were casted and tested. Further, an attempt has been made to compare the experimental load carrying capacity with the conventional mechanics based approach used for analyzing short columns. There was a fairly good co-relation between the analysis and experiments. Key Words: Unreinforced Masonry, Reinforced Hollow Concrete Block Masonry.
Influence of micropolar lubricant on bearings performance a review(2)susheelpote
This review article summarizes research on the influence of micropolar lubricants on bearing performance. Micropolar lubricants account for the microstructural effects of additives and contaminants in lubricating oils. The article first introduces micropolar fluid theory, which generalizes the Navier-Stokes equations to include microrotation effects. It then reviews how micropolar theory has been applied to analyze the performance of various bearing configurations, including slider, thrust, step slider, and journal bearings. The performance metrics considered include load capacity, friction, flow, heat generation, and stability. Research has found micropolar lubricants can increase load capacity and reduce friction in many bearing types compared to classical Newtonian lubric
A study on plastic hinge formation in rc frame by nonlinear static analysiseSAT Journals
This document presents a study on plastic hinge formation in reinforced concrete (RC) frames under nonlinear static pushover analysis. A single-bay, single-story RC frame is modeled and analyzed using SAP2000 software. The order and location of plastic hinge formation is observed as the frame is subjected to incremental lateral loading. Four plastic hinges form in total. The sequence of hinge formation is found to control the deformation behavior of the frame. Understanding hinge formation and the gap between successive hinges forming provides better insight into the performance of the structure under earthquake ground motions.
Static Structural, Fatigue and Buckling Analysis of Jet Pipe Liner by Inducin...IRJET Journal
This document analyzes the static structural, fatigue, and buckling behavior of conventional and corrugated jet pipe liners through finite element analysis. A conventional liner model and optimized corrugated liner model were created and meshed. Static structural analysis found that the corrugated liner had lower deformation and similar von-Mises stresses to the conventional liner. Fatigue analysis determined the corrugated liner had a slightly lower fatigue life but still above the design target of 1 million cycles. Buckling analysis revealed the corrugated liner had a higher buckling load multiplier, indicating it is stiffer than the conventional liner against buckling. In conclusion, introducing corrugation improved the liner's buckling strength without negatively impacting other
The Comparison of Properties of Tinplates during Uniaxial and Biaxial Stresstheijes
The majority of thin steel sheets is used to make of food covers, cans, capsules and other products, which are produced by metal forming. Concerning considerable changes in production of tinplates and still higher requests on their properties there is requirement to use such methods on their evaluation, which are able to determine especially mechanical and plastic properties of sheets quickly and with the low costs. Following of present know-how there were developed new testing methods, which correspond more to steel sheets stress during technological treatment (concerning their stress-strain state). In the contribution we deal with the comparison of properties of tinplates during uniaxial tensile test and biaxial tensile test.
Based on the experimental and numerical studies performed by NIST an Alternative Load Path Analysis (ALPA) guideline is being developed by the Disproportionate Collapse Technical Committee to provide design, analysis and modeling methods for engineers in practice to reduce the vulnerability of steel and concrete structures to disproportionate collapse. This article presents a summary of chapter 3 of this guideline, titled Simplified Analysis to Predict Collapse Resistance. Chapter 3 focuses on simplified analysis methods that can be applied in form of spreadsheets or closed form solutions to predict the collapse capacity of steel and concrete buildings.
1) An experimental study was conducted to compare the compression behavior of normal strength concrete (NSC) and self-compacting concrete (SCC) intermediate columns.
2) Six column specimens with a cross-section of 125x125mm and a height of 1.5m were tested under axial loading. The columns varied in concrete type (NSC and SCC) and longitudinal reinforcement ratio (2.09%, 2.89%, 5.15%).
3) The results showed that as the reinforcement ratio increased, the ultimate load capacity increased and axial deformation decreased for both NSC and SCC columns. However, SCC columns exhibited higher ultimate loads and deformations than NSC columns for the same reinforcement ratio.
IRJET- Buckling Evaluation of a Plastic Bottle DesignIRJET Journal
This document presents research on evaluating the buckling of a plastic bottle design through finite element simulation. Researchers created a geometric model of a PET bottle in SolidWorks and imported it into ABAQUS for meshing and analysis. Static, buckling, and dynamic analyses were performed to determine maximum stress, buckling modes, and structural response under crushing loads. The bottle thickness was optimized to reduce weight while maintaining strength. Top load testing validated the model, showing a maximum vertical deflection of 59.2mm and maximum stress of 119MPa, below the yield point, confirming the design is safe. The study provides a method for optimizing plastic bottle structure through finite element analysis.
Design Modification of Failure Mode Effect Analysis of Vibrating Feeder used ...ijsrd.com
Vibratin feeder technology is common in material handling applications in numerous industries. This review paper examines a problem with fatigue in the support structure of a specific type of vibrating feeder. It also reviews the theory behind vibrating feeder technology and considerations that engineers who design them need to be aware of. The finite element method is used to replicate a fatigue problem in the support structure and various design configurations are then analyzed to reduce the risk of the conditions that caused the fatigue. The results are reviewed and recommendations are made to improve the design and modify the component dimensional parameters vibrating feeder.
Stress Analysis of Automotive Chassis with Various ThicknessesIOSR Journals
Abstract : This paper presents, stress analysis of a ladder type low loader truck chassis structure consisting of
C-beams design for application of 7.5 tonne was performed by using FEM. The commercial finite element
package CATIA version 5 was used for the solution of the problem. To reduce the expenses of the chassis of the
trucks, the chassis structure design should be changed or the thickness should be decreased. Also determination
of the stresses of a truck chassis before manufacturing is important due to the design improvement. In order to
achieve a reduction in the magnitude of stress at critical point of the chassis frame, side member thickness,
cross member thickness and position of cross member from rear end were varied. Numerical results showed that
if the thickness change is not possible, changing the position of cross member may be a good alternative.
Computed results are then compared to analytical calculation, where it is found that the maximum deflection
agrees well with theoretical approximation but varies on the magnitude aspect.
Keywords - Stress analysis, fatigue life prediction and finite element method etc.
This document summarizes a failure analysis of diesel engine crankshafts made of nodular cast iron that failed prematurely. Examination found that all failures occurred in the first crankpin nearest to the flywheel. Finite element modeling revealed high stresses in this region. However, fatigue analysis found the stresses were within safe limits. Scanning electron microscopy of fracture surfaces showed brittle cleavage fracture rather than fatigue, indicating an overload likely caused the failure. The document recommends re-evaluating the crankshaft design and manufacturing process, particularly fillet rolling, to prevent future failures.
Modeling and finite element analysis for a casting defect in thin wall struct...Dr.Vikas Deulgaonkar
This document summarizes a study that used finite element analysis to model and simulate casting defects in thin-walled aluminum pump impeller structures. Various simulations were run to analyze factors like metal flow, heat transfer, solidification temperatures, and defect formation under different conditions. Actual castings were also produced and tested. The results showed that increasing the number of risers from one to three reduced blow holes and other defects, indicating the importance of proper gating and feeding systems to minimize defects in thin-walled castings. Comparisons between simulation temperatures and experimental temperatures also showed good agreement.
A Method for Probabilistic Stability Analysis of Earth DamsIJERA Editor
This paper proposes a new probabilistic methodology for analyzing the stability of Earth Dams, based on the
technique of the First Order Reliability Method for Structural Reliability. Differently from others methodologies
present in literature, the proposed method interprets the involved variables as random ones. So, three results are
provided here: the Structural Reliability Index, the Probability of Rupture and the most probable values of the
random variables for the occurrence of a dam break. In order to illustrate it, real data from a cross section of the
Left Bank Earthfill Dam of Itaipu Hydroelectric Power Plant (IHPP), located on the city of Foz do Iguaçu,
Paraná, Brazil were used. The numerical results achieved by the proposed methodology evidence that IHPP dam
has currently good structural conditions, confirming that the safety procedures adopted in Itaipu Dam may be
considered as appropriate. The use of the proposed method enables to complement the previously existing
knowledge about the structural conditions, improving the process of risk management.
International Journal of Engineering Research and Applications (IJERA) aims to cover the latest outstanding developments in the field of all Engineering Technologies & science.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
IRJET - A Review on Tuned Liquid Column Dampers (TLCDS) and Tuned Liquid Colu...IRJET Journal
This document reviews Tuned Liquid Column Dampers (TLCDs) and two modifications: Tuned Liquid Column Dampers with Embossments (ETLCDs) and Liquid Column Vibration Absorbers (LCVAs). TLCDs use sloshing liquid to absorb vibrations in structures. ETLCDs and LCVAs improve upon TLCD damping. Studies show ETLCDs and LCVAs more effectively reduce structural displacement and acceleration compared to TLCDs. ETLCDs have embossments to increase damping, while LCVAs have different horizontal and vertical cross-sectional areas. Both modifications perform better than conventional TLCDs at mitigating vibrational responses.
IRJET- Fatigue Life Evaluation of Composite Material Leaf Spring- Numerical a...IRJET Journal
This document discusses evaluating the fatigue life of composite material leaf springs through numerical and experimental methods. It begins with an introduction to leaf springs, composites, and fatigue. Then it describes modeling a composite leaf spring in ANSYS Workbench to conduct finite element analysis and numerically evaluate fatigue life. Charts and tables show the results of the numerical analysis, including fatigue life predictions for the composite leaf spring. The document indicates experimental analysis will also be used to validate the numerical results.
CFD Analysis of Fluid Film Journal Bearing: A ReviewIRJET Journal
This document provides a review of computational fluid dynamics (CFD) analysis that has been performed on fluid film journal bearings. It summarizes 14 papers that analyzed pressure and temperature distribution in journal bearings under various conditions. These papers used CFD to study how parameters like speed, load, eccentricity ratio, and lubricant properties affect the pressure and temperature fields. The document also summarizes 5 papers that used fluid-structure interaction (FSI) methods to study deformation of the bearing surface. And it summarizes 6 papers that analyzed how parameters influence the load carrying capacity of journal bearings. The objective of the review was to evaluate how CFD analysis has provided insights into journal bearing performance.
Flexural behaviour of interior r.c.beam column joint with and without slab un...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This paper involves an experimental investigation on the flexural behaviour of curved beams and comparison of its results with conventional beams. Curved beams of size 1200 x 150 x 100 mm with varying initial curvature as 4000mm, 2000mm and the concrete strength as M40 is considered. Various reinforcement are provided in the curved beams to predict which reinforcement detail would give more resistant over maximum loading. The material properties of cement, fine aggregate, coarse aggregate and the compressive strength of concrete cube were found out. A total of 12 specimens of curved beams were casted with various combination of reinforcement along with three control specimens. The beams are tested under two point loading both horizontally and vertically. The deflection and maximum moment carrying capacity are investigated to understand its strength. Also analytical modelling is done to determine the ultimate moment carrying capacity using Finite Element Software ABAQUS to compare with the experimental model.
Microstructure analysis of steel 85 & al 7050 for cold expanded holeseSAT Publishing House
1) The document analyzes the microstructure of steel 85 and aluminum 7050 that have undergone cold expansion of holes. Micrographs show zones of plastic and elastic deformation created by the expansion.
2) The micrographs clearly show a zone of plastic deformation close to the hole followed by a zone of elastic compression induced by the split sleeve expansion. The pattern changes with different extents of expansion.
3) Analysis found that plastic deformation increases with higher percentages of hole expansion. The zones of plastic deformation were also thicker closer to the expanded hole.
Stability Analysis of Journal Bearing Using Electro Rheological Fluid by Fini...ijsrd.com
in rotating machinery, the damping of structure which supports the rotating shaft has significant effect in machine vibration. Therefore by controlling the lubricant properties, the dynamic behavior of the system can be controlled. The objective of this paper is to study the dynamic behavior of a rotor supported by a journal bearing and fed with Electro-rheological (ER) fluid. ER fluids can be used to create ‘smart’ journal bearings & vibration controllers can be constructed to control the Stability of the ER fluid lubricated bearings. The ER fluid behaves like a Bingham fluid with a higher viscosity when electric field is applied, and restores its property when the field is removed. A reversible change in viscosity occurs in milliseconds with the electric field applied.
Pins require very little service and total failure seldom occurs. Wear, pitting, and scoring are the usual troubles
encountered with pins. In this paper, going to apply induction hardening process on pins and its comparison will
be done with existing pins. Different hardening thickness or case depth will be applied and analysis will be done
to interpret the results. Case depth of 1mm, 2mm or 2.5mm will be taken in induction hardening process.
Caterpillar 320dl excavator model is taken for study. Material used for the pins is EN8 grade of steel. And
different material used for the pin for analysis purpose will be bronze alloy, Titanium. The main objective in this
project is to determine the appropriate induction hardening case depth to be used in manufacturing pins.ThreedHiympeenrsmioensh
m aondde Alsn osfy sp iwnisl lu bseed u sined e xtoc aavnaatloyrz ew tihlle bsetr ecsres astteadtu uss oinng t hCea ptiianVs.5 T shoef tmwaarxei,m mumes hdienfgo rwmiallt iboen ,d monaex iumsuinmg
stress point and dangerous areas are found by the stress analysis.
Effect of the post weld heat treatments on the fatigue crack growth behavior ...eSAT Journals
Abstract
The effect of the post weld heat treatments (PWHTs) on the fatigue crack growth (FCG) behavior in the welded zone of AA6063-T5 fabricated by the friction stir process was investigated. The FCG specimens are machined in which the loading axis is put perpendicular to the welding line and the initial notches are introduced in the welded zone. The experimental results showed the FCG rates are sensitive to the PWHT solutions. The FCG resistance in the welded zone could be fully restored to that of base metal by using PWHT. While the PWHT solution solely restores the precipitates dissolved and/or coarsened during welding process has a minor effect on the FCG rates, the PWHT solution remarkably recrystallizes the grain microstructure has a significant effect here.
Keywords: Aluminum alloy, Failure assessment, Fatigue crack propagation, Friction stir welding
IRJET- Design and Analysis of Crane Hook by using Composite MaterialIRJET Journal
This document describes a study that analyzed the design and stresses in a crane hook made of compacted graphite iron composite material compared to a forged steel crane hook. The crane hook model was designed in CATIA V5 and then both materials were analyzed in ANSYS for stresses and deformations under load. The results showed that the compacted graphite iron crane hook had lower stresses and weight than the forged steel design. Therefore, the study concluded that compacted graphite iron could be an improved alternative material for crane hooks compared to traditional forged steel.
ANALYTICAL AND EXPERIMENTAL EVALUATION OF SPRING BACK EFFECTS IN A TYPICAL ...IAEME Publication
Prediction of spring back for forming of a typical shape of Cold Rolled steel sheet has been carried out using FEM. The objective of this work is to predict the spring back in the form of a typical shape of cold rolled steel sheet and compare that with the actual spring back as occurs in experiment. A typical shape is designed using AutoCAD and Solidworks. Die and punch to form the shape has been designed using 2d and 3d modelling tools. The Finite element simulation is done considering the material and geometric nonlinearity. Non-linear material properties are obtained from the tensile testing of the standard test specimen made from the same material and of same thickness. Geometric nonlinearity is considered by selecting appropriate option in the FEM package.
The document discusses buildings with base isolation techniques. It provides an overview of base isolation, including definitions of earthquakes, structural bearings, design requirements, and construction of base isolated buildings. It also presents a case study comparing the behavior of a fixed base building to a building with a base isolation system, using finite element modeling and modal analysis. The base isolated building showed significantly lower and longer period modal frequencies, indicating better seismic performance.
The document discusses vibration control systems for structures and summarizes a presentation on the Yokohama Land Mark Tower in Japan. It describes how the tower implements a hybrid mass damper (HMD) system to control vibrations from earthquakes and wind. The HMD combines a tuned mass damper with an active control actuator. Two 170-ton HMD units were installed in the tower and automatically switch between active and passive modes to reduce vibrations by up to 50%. The hybrid system allows for increased efficiency and robustness compared to a purely passive or active vibration control system.
This document discusses seismic retrofitting and base isolation systems. It defines seismic retrofitting as modifying existing structures to make them more resistant to seismic activity. The most widely used retrofitting method is base isolation, which involves inserting rubber or similar isolators between a building's foundation and superstructure. This allows for slight lateral movement during an earthquake to increase the building's natural period and reduce seismic forces. There are two main types of base isolators: sliding systems and elastometric isolators, with lead rubber bearings being a common elastometric isolator that uses lead plugs to dissipate energy and limit displacement. Base isolation has been used worldwide to reinforce historical structures and reduce earthquake damage to buildings and artifacts.
This document provides an overview of base isolation, which is a seismic protection system that mitigates earthquake damage by isolating structures from ground motions. It discusses the concepts of base isolation, including introducing flexibility to reduce transmitted forces. Common isolation components like elastomeric and lead-rubber bearings are described. The document also covers principles, suitability, differences between isolated and fixed structures, and real-world applications of base isolation in over 1000 buildings worldwide.
This document provides a summary of base isolation as a seismic retrofitting technique. It defines base isolation as decoupling a structure from its foundation to protect it during earthquakes. It describes different types of base isolators using materials like rubber, lead and steel. Advantages include reducing structural damage, secondary damage, and maintenance costs. Disadvantages include challenges implementing for tall buildings. Examples of base isolated structures worldwide and in India are given. The document concludes with suggestions for government initiatives to develop this technology in India.
Design Modification of Failure Mode Effect Analysis of Vibrating Feeder used ...ijsrd.com
Vibratin feeder technology is common in material handling applications in numerous industries. This review paper examines a problem with fatigue in the support structure of a specific type of vibrating feeder. It also reviews the theory behind vibrating feeder technology and considerations that engineers who design them need to be aware of. The finite element method is used to replicate a fatigue problem in the support structure and various design configurations are then analyzed to reduce the risk of the conditions that caused the fatigue. The results are reviewed and recommendations are made to improve the design and modify the component dimensional parameters vibrating feeder.
Stress Analysis of Automotive Chassis with Various ThicknessesIOSR Journals
Abstract : This paper presents, stress analysis of a ladder type low loader truck chassis structure consisting of
C-beams design for application of 7.5 tonne was performed by using FEM. The commercial finite element
package CATIA version 5 was used for the solution of the problem. To reduce the expenses of the chassis of the
trucks, the chassis structure design should be changed or the thickness should be decreased. Also determination
of the stresses of a truck chassis before manufacturing is important due to the design improvement. In order to
achieve a reduction in the magnitude of stress at critical point of the chassis frame, side member thickness,
cross member thickness and position of cross member from rear end were varied. Numerical results showed that
if the thickness change is not possible, changing the position of cross member may be a good alternative.
Computed results are then compared to analytical calculation, where it is found that the maximum deflection
agrees well with theoretical approximation but varies on the magnitude aspect.
Keywords - Stress analysis, fatigue life prediction and finite element method etc.
This document summarizes a failure analysis of diesel engine crankshafts made of nodular cast iron that failed prematurely. Examination found that all failures occurred in the first crankpin nearest to the flywheel. Finite element modeling revealed high stresses in this region. However, fatigue analysis found the stresses were within safe limits. Scanning electron microscopy of fracture surfaces showed brittle cleavage fracture rather than fatigue, indicating an overload likely caused the failure. The document recommends re-evaluating the crankshaft design and manufacturing process, particularly fillet rolling, to prevent future failures.
Modeling and finite element analysis for a casting defect in thin wall struct...Dr.Vikas Deulgaonkar
This document summarizes a study that used finite element analysis to model and simulate casting defects in thin-walled aluminum pump impeller structures. Various simulations were run to analyze factors like metal flow, heat transfer, solidification temperatures, and defect formation under different conditions. Actual castings were also produced and tested. The results showed that increasing the number of risers from one to three reduced blow holes and other defects, indicating the importance of proper gating and feeding systems to minimize defects in thin-walled castings. Comparisons between simulation temperatures and experimental temperatures also showed good agreement.
A Method for Probabilistic Stability Analysis of Earth DamsIJERA Editor
This paper proposes a new probabilistic methodology for analyzing the stability of Earth Dams, based on the
technique of the First Order Reliability Method for Structural Reliability. Differently from others methodologies
present in literature, the proposed method interprets the involved variables as random ones. So, three results are
provided here: the Structural Reliability Index, the Probability of Rupture and the most probable values of the
random variables for the occurrence of a dam break. In order to illustrate it, real data from a cross section of the
Left Bank Earthfill Dam of Itaipu Hydroelectric Power Plant (IHPP), located on the city of Foz do Iguaçu,
Paraná, Brazil were used. The numerical results achieved by the proposed methodology evidence that IHPP dam
has currently good structural conditions, confirming that the safety procedures adopted in Itaipu Dam may be
considered as appropriate. The use of the proposed method enables to complement the previously existing
knowledge about the structural conditions, improving the process of risk management.
International Journal of Engineering Research and Applications (IJERA) aims to cover the latest outstanding developments in the field of all Engineering Technologies & science.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
IRJET - A Review on Tuned Liquid Column Dampers (TLCDS) and Tuned Liquid Colu...IRJET Journal
This document reviews Tuned Liquid Column Dampers (TLCDs) and two modifications: Tuned Liquid Column Dampers with Embossments (ETLCDs) and Liquid Column Vibration Absorbers (LCVAs). TLCDs use sloshing liquid to absorb vibrations in structures. ETLCDs and LCVAs improve upon TLCD damping. Studies show ETLCDs and LCVAs more effectively reduce structural displacement and acceleration compared to TLCDs. ETLCDs have embossments to increase damping, while LCVAs have different horizontal and vertical cross-sectional areas. Both modifications perform better than conventional TLCDs at mitigating vibrational responses.
IRJET- Fatigue Life Evaluation of Composite Material Leaf Spring- Numerical a...IRJET Journal
This document discusses evaluating the fatigue life of composite material leaf springs through numerical and experimental methods. It begins with an introduction to leaf springs, composites, and fatigue. Then it describes modeling a composite leaf spring in ANSYS Workbench to conduct finite element analysis and numerically evaluate fatigue life. Charts and tables show the results of the numerical analysis, including fatigue life predictions for the composite leaf spring. The document indicates experimental analysis will also be used to validate the numerical results.
CFD Analysis of Fluid Film Journal Bearing: A ReviewIRJET Journal
This document provides a review of computational fluid dynamics (CFD) analysis that has been performed on fluid film journal bearings. It summarizes 14 papers that analyzed pressure and temperature distribution in journal bearings under various conditions. These papers used CFD to study how parameters like speed, load, eccentricity ratio, and lubricant properties affect the pressure and temperature fields. The document also summarizes 5 papers that used fluid-structure interaction (FSI) methods to study deformation of the bearing surface. And it summarizes 6 papers that analyzed how parameters influence the load carrying capacity of journal bearings. The objective of the review was to evaluate how CFD analysis has provided insights into journal bearing performance.
Flexural behaviour of interior r.c.beam column joint with and without slab un...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology.
This paper involves an experimental investigation on the flexural behaviour of curved beams and comparison of its results with conventional beams. Curved beams of size 1200 x 150 x 100 mm with varying initial curvature as 4000mm, 2000mm and the concrete strength as M40 is considered. Various reinforcement are provided in the curved beams to predict which reinforcement detail would give more resistant over maximum loading. The material properties of cement, fine aggregate, coarse aggregate and the compressive strength of concrete cube were found out. A total of 12 specimens of curved beams were casted with various combination of reinforcement along with three control specimens. The beams are tested under two point loading both horizontally and vertically. The deflection and maximum moment carrying capacity are investigated to understand its strength. Also analytical modelling is done to determine the ultimate moment carrying capacity using Finite Element Software ABAQUS to compare with the experimental model.
Microstructure analysis of steel 85 & al 7050 for cold expanded holeseSAT Publishing House
1) The document analyzes the microstructure of steel 85 and aluminum 7050 that have undergone cold expansion of holes. Micrographs show zones of plastic and elastic deformation created by the expansion.
2) The micrographs clearly show a zone of plastic deformation close to the hole followed by a zone of elastic compression induced by the split sleeve expansion. The pattern changes with different extents of expansion.
3) Analysis found that plastic deformation increases with higher percentages of hole expansion. The zones of plastic deformation were also thicker closer to the expanded hole.
Stability Analysis of Journal Bearing Using Electro Rheological Fluid by Fini...ijsrd.com
in rotating machinery, the damping of structure which supports the rotating shaft has significant effect in machine vibration. Therefore by controlling the lubricant properties, the dynamic behavior of the system can be controlled. The objective of this paper is to study the dynamic behavior of a rotor supported by a journal bearing and fed with Electro-rheological (ER) fluid. ER fluids can be used to create ‘smart’ journal bearings & vibration controllers can be constructed to control the Stability of the ER fluid lubricated bearings. The ER fluid behaves like a Bingham fluid with a higher viscosity when electric field is applied, and restores its property when the field is removed. A reversible change in viscosity occurs in milliseconds with the electric field applied.
Pins require very little service and total failure seldom occurs. Wear, pitting, and scoring are the usual troubles
encountered with pins. In this paper, going to apply induction hardening process on pins and its comparison will
be done with existing pins. Different hardening thickness or case depth will be applied and analysis will be done
to interpret the results. Case depth of 1mm, 2mm or 2.5mm will be taken in induction hardening process.
Caterpillar 320dl excavator model is taken for study. Material used for the pins is EN8 grade of steel. And
different material used for the pin for analysis purpose will be bronze alloy, Titanium. The main objective in this
project is to determine the appropriate induction hardening case depth to be used in manufacturing pins.ThreedHiympeenrsmioensh
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stress point and dangerous areas are found by the stress analysis.
Effect of the post weld heat treatments on the fatigue crack growth behavior ...eSAT Journals
Abstract
The effect of the post weld heat treatments (PWHTs) on the fatigue crack growth (FCG) behavior in the welded zone of AA6063-T5 fabricated by the friction stir process was investigated. The FCG specimens are machined in which the loading axis is put perpendicular to the welding line and the initial notches are introduced in the welded zone. The experimental results showed the FCG rates are sensitive to the PWHT solutions. The FCG resistance in the welded zone could be fully restored to that of base metal by using PWHT. While the PWHT solution solely restores the precipitates dissolved and/or coarsened during welding process has a minor effect on the FCG rates, the PWHT solution remarkably recrystallizes the grain microstructure has a significant effect here.
Keywords: Aluminum alloy, Failure assessment, Fatigue crack propagation, Friction stir welding
IRJET- Design and Analysis of Crane Hook by using Composite MaterialIRJET Journal
This document describes a study that analyzed the design and stresses in a crane hook made of compacted graphite iron composite material compared to a forged steel crane hook. The crane hook model was designed in CATIA V5 and then both materials were analyzed in ANSYS for stresses and deformations under load. The results showed that the compacted graphite iron crane hook had lower stresses and weight than the forged steel design. Therefore, the study concluded that compacted graphite iron could be an improved alternative material for crane hooks compared to traditional forged steel.
ANALYTICAL AND EXPERIMENTAL EVALUATION OF SPRING BACK EFFECTS IN A TYPICAL ...IAEME Publication
Prediction of spring back for forming of a typical shape of Cold Rolled steel sheet has been carried out using FEM. The objective of this work is to predict the spring back in the form of a typical shape of cold rolled steel sheet and compare that with the actual spring back as occurs in experiment. A typical shape is designed using AutoCAD and Solidworks. Die and punch to form the shape has been designed using 2d and 3d modelling tools. The Finite element simulation is done considering the material and geometric nonlinearity. Non-linear material properties are obtained from the tensile testing of the standard test specimen made from the same material and of same thickness. Geometric nonlinearity is considered by selecting appropriate option in the FEM package.
The document discusses buildings with base isolation techniques. It provides an overview of base isolation, including definitions of earthquakes, structural bearings, design requirements, and construction of base isolated buildings. It also presents a case study comparing the behavior of a fixed base building to a building with a base isolation system, using finite element modeling and modal analysis. The base isolated building showed significantly lower and longer period modal frequencies, indicating better seismic performance.
The document discusses vibration control systems for structures and summarizes a presentation on the Yokohama Land Mark Tower in Japan. It describes how the tower implements a hybrid mass damper (HMD) system to control vibrations from earthquakes and wind. The HMD combines a tuned mass damper with an active control actuator. Two 170-ton HMD units were installed in the tower and automatically switch between active and passive modes to reduce vibrations by up to 50%. The hybrid system allows for increased efficiency and robustness compared to a purely passive or active vibration control system.
This document discusses seismic retrofitting and base isolation systems. It defines seismic retrofitting as modifying existing structures to make them more resistant to seismic activity. The most widely used retrofitting method is base isolation, which involves inserting rubber or similar isolators between a building's foundation and superstructure. This allows for slight lateral movement during an earthquake to increase the building's natural period and reduce seismic forces. There are two main types of base isolators: sliding systems and elastometric isolators, with lead rubber bearings being a common elastometric isolator that uses lead plugs to dissipate energy and limit displacement. Base isolation has been used worldwide to reinforce historical structures and reduce earthquake damage to buildings and artifacts.
This document provides an overview of base isolation, which is a seismic protection system that mitigates earthquake damage by isolating structures from ground motions. It discusses the concepts of base isolation, including introducing flexibility to reduce transmitted forces. Common isolation components like elastomeric and lead-rubber bearings are described. The document also covers principles, suitability, differences between isolated and fixed structures, and real-world applications of base isolation in over 1000 buildings worldwide.
This document provides a summary of base isolation as a seismic retrofitting technique. It defines base isolation as decoupling a structure from its foundation to protect it during earthquakes. It describes different types of base isolators using materials like rubber, lead and steel. Advantages include reducing structural damage, secondary damage, and maintenance costs. Disadvantages include challenges implementing for tall buildings. Examples of base isolated structures worldwide and in India are given. The document concludes with suggestions for government initiatives to develop this technology in India.
This document introduces base isolation as a seismic retrofitting technique. It defines base isolation as decoupling a structure's superstructure from its substructure using structural elements. The document discusses the principle of base isolation, which is to isolate the structure from ground movement. It compares base isolation to other retrofitting techniques, noting advantages such as reduced structural damage and maintenance costs. The document also outlines different base isolation systems using elastomeric bearings and sliding systems. Examples of base isolation projects and companies utilizing the technique are provided. The document suggests government initiatives and training to develop base isolation in India.
This document presents the seismic design project of a 12-story steel frame building in Stockton, California. The objectives are to analyze the building using equivalent lateral force (ELF), modal response spectrum, and modal time history analyses in SAP2000, and to compare the results to FEMA 451 examples. The building is irregular in plan and elevation, posing modeling challenges. The analyses determine member forces and drifts. ELF analysis results in story drifts up to 3.58 inches, within code allowables. Modal and time history analyses will provide more accurate force and deformation estimates for design.
The document discusses base isolation as an earthquake protection system. It begins with an introduction to earthquakes and then defines base isolation as a system that uses flexible interfaces between a structure and its foundation to decouple the structure from ground motions during an earthquake. It describes various types of base isolation systems, including sliding and elastomeric bearing systems, and discusses considerations for implementing base isolation for structures. It provides an example of base isolation being used in a new hospital built after the collapse of a hospital during an earthquake in India.
The document discusses the structure of the Earth and the causes of earthquakes. It describes the three main layers of the Earth - crust, mantle, and core. It explains that earthquakes are caused by the movement of tectonic plates at divergent, convergent, and transform plate boundaries. The document also summarizes methods of earthquake-resistant design, including base isolation devices that separate buildings from the ground and seismic dampers that absorb seismic energy. It notes that while base isolation can be used for existing structures, seismic dampers are more expensive to install. The conclusion emphasizes the importance of earthquake-resistant construction and quality control to ensure public safety.
The document discusses earthquakes and techniques for improving earthquake resistance in buildings. It defines earthquakes and describes how they occur due to movement in the earth's crust. It then covers types of earthquakes, causes and effects, seismic waves, and performance and design considerations for improving earthquake resistance. Specific techniques discussed include using shear walls, base isolation methods, energy dissipation devices, and keeping buildings in compression. The conclusion emphasizes following construction standards and periodic training to help assure earthquake-resistant buildings.
Base isolation is one of the most widely accepted seismic protection systems in earthquake prone areas. It mitigates the effect of an earthquake by essentially isolating the structure from potentially dangerous ground motions, especially in frequency range where building is mostly affected. This includes
Concept of Base Isolation
Principle of Base Isolation
Comparison of Fixed Base Structure and Isolated Base Structure
Types of Isolation Components
Base Isolation in Real Buildings
Applications of Base Isolation
This document summarizes a study on the seismic performance of reinforced concrete (RC) framed structures designed using the partial capacity design (PCD) method. PCD aims to ensure plastic hinges only form at expected locations by designing interior columns for nominal seismic loads and exterior columns for higher seismic loads using a magnification factor formula. The study models 2D and 3D RC frames in SAP software and designs them according to Indian codes using the new magnification factor formula. Nonlinear pushover analysis shows the frames achieve the assumed collapse mechanism as exterior columns remain elastic. Overstrength factors between 1.03-1.21 and magnification factors between 2.35-3.87 are calculated for the frames. The study concludes PCD is effective if exterior column
Seismic Retrofitting of Structures – A ReviewIRJET Journal
This document reviews various techniques for seismic retrofitting of structures. It begins with an introduction to seismic retrofitting and discusses common global retrofitting methods like jacketing with fiber reinforced polymers, steel cages, or ferrocement. Additional methods mentioned include adding shear walls. The literature review then summarizes several papers on retrofitting techniques and their effectiveness as evaluated through testing and analysis. These include jacketing, addition of walls, use of dampers, and stiffness reduction methods. Overall, the document provides an overview of seismic retrofitting techniques and research evaluating their ability to improve structures' load capacity, ductility, and seismic performance.
Numerical study on behaviour eccentrically loaded double circular steel tubul...IRJET Journal
This document presents a numerical study on the behavior of eccentrically loaded double circular steel tubular short columns filled with concrete. An Abaqus finite element model was developed and validated against experimental results from literature. The model considered material nonlinearities, confinement effects, and bond. Comparisons showed good agreement between experimental and numerical load-displacement curves, capacities, and failure modes. Parametric studies were then conducted using the model to analyze the performance of columns with varying geometries, materials, and loading conditions. The research aims to enhance understanding and modeling of these composite columns to inform design practices.
Effect of Residual Modes on Dynamically Condensed Spacecraft StructureIRJET Journal
This document discusses the effect of residual modes on the fundamental frequencies of a condensed spacecraft structure. It presents the modeling and dynamic analysis of a spacecraft bus structure using finite element analysis. The structure is condensed using the Craig-Bampton method to reduce the degrees of freedom. Residual modes are then computed and included to recover data lost during condensation. The results show that including residual modes provides frequencies for the condensed structure that closely match those of the original full structure model, demonstrating the effectiveness of using residual modes for data recovery after structural condensation.
IRJET- Study on Parametric Behaviour of Box Girder Bridges under Different Ra...IRJET Journal
This document discusses several topics related to the analysis and design of box girder bridges, including:
1. A study on the parametric behavior of box girder bridges under different radii of curvature and varying spans.
2. Dynamic analysis methods for evaluating the response of railway bridges to moving high-speed trains, including the importance of structural damping.
3. Pushover analysis methods for evaluating the seismic performance of balanced cantilever bridges.
4. Time history analysis methods for assessing dynamic load allowance factors for reinforced concrete bridges subjected to moving live loads.
5. Seismic analysis of a multi-span box girder bridge using nonlinear time history analysis to determine seismic response.
This document provides an overview and table of contents for a textbook on embedded systems using ARM architecture. It discusses how 32-bit systems like those based on ARM are becoming the mainstream for embedded systems due to their improved processing capabilities over 8-bit and 16-bit systems. It also notes that existing books on ARM focus on chip design, applications, or development boards rather than application development suitable for undergraduate teaching, which is the purpose of this textbook. The table of contents outlines chapters on embedded systems, embedded systems engineering, and the ARM7 architecture.
Non linear static pushover analysis of irregular space frame structure with a...eSAT Publishing House
IJRET : International Journal of Research in Engineering and Technology is an international peer reviewed, online journal published by eSAT Publishing House for the enhancement of research in various disciplines of Engineering and Technology. The aim and scope of the journal is to provide an academic medium and an important reference for the advancement and dissemination of research results that support high-level learning, teaching and research in the fields of Engineering and Technology. We bring together Scientists, Academician, Field Engineers, Scholars and Students of related fields of Engineering and Technology
Performance of profiled I shaped dampers as energy dissipation system for bra...IRJET Journal
The document discusses the performance of I-shaped profiled dampers as an energy dissipation system for braced steel structures. Finite element models of a braced steel frame with and without dampers were created and analyzed under lateral loading. Parametric studies were conducted by varying the dimensions of the I-shaped profiled damper, including web height, width, and thickness, to determine the optimum size that provides the best seismic performance. The results found that adding dampers to the braced frame increased its ductility and energy dissipation capacity compared to the braced frame alone. However, the strength was lower than the braced frame. Further parametric studies are needed to find the damper size that achieves high strength
International Journal of Computational Engineering Research(IJCER)ijceronline
International Journal of Computational Engineering Research(IJCER) is an intentional online Journal in English monthly publishing journal. This Journal publish original research work that contributes significantly to further the scientific knowledge in engineering and Technology.
PROGRESSIVE COLLAPSE ANALYSIS OF REINFORCED CONCRETE STRUCTURES WITH FLAT SLA...IRJET Journal
This document summarizes a research study that analyzes the progressive collapse resistance of reinforced concrete flat slab structures considering various geometrical irregularities. Five structural models are considered - a regular rectangular structure, structures with re-entrant corners, excessive openings, vertical irregularities, and mass irregularities. A 10-story reinforced concrete flat slab building is modeled and analyzed using the equivalent frame method. Progressive collapse analysis is conducted by removing critical ground-level columns and evaluating demand-capacity ratios and deformations based on GSA and DOD guidelines. The goal is to understand how geometrical irregularities impact a structure's ability to resist progressive collapse when columns are removed.
“A REVIEW STUDY ON PUSHOVER ANALYSIS OF SYMMETRIC BUILDING ON FLAT & SLOPING ...IRJET Journal
This document summarizes pushover analysis that was conducted on symmetric buildings located on flat and sloping surfaces. Pushover analysis using ETABS software evaluated how dynamic features like base shear, roof displacement, and hinge formation differed between building models. Previous studies on pushover analysis of buildings on sloping ground with or without soil-structure interaction were also reviewed. The analysis found that buildings on sloping surfaces experienced less displacement and softer story drift compared to equivalent buildings on flat surfaces. Hinge conditions at the performance point provided insights into the structural response.
Finite Element Modeling of a Multi-Storeyed Retrofitted Reinforced Concrete F...IOSR Journals
In the present study, the non-linear response of RC frame using FE modeling under the incremental
loading has been carried out in the first phase of analysis to study the response and load-carrying capacity of a
four storeyed RC frame using non-linear finite element analysis. In the second phase of study an analysis model
for retrofitted RC frame using finite element method using software ATENA is presented. The results obtained
from FE analysis in both cases are compared with the experimental data for four storeyed RC frame tested by
BARC at CPRI. The results from finite element analysis were calculated at the same location as used in
experimental test. The accuracy of the finite element model is assessed by the comparison with experimental
results which are to be in good agreement. The base shear/ displacement curves from finite element analysis
agree well with the experimental results in linear range. The maximum difference in base shear is observed to
be 7.9%
Structural Performance of Jacketing in Reinforced Concrete Columns: A Brief S...IRJET Journal
This document summarizes research on retrofitting reinforced concrete columns through jacketing. It discusses using reinforced concrete jacketing, fiber reinforced polymer wrapping, and steel jacketing to strengthen seismic deficient columns. A typical residential building located in a high seismic zone of India is modeled and analyzed to compare the structural behavior of columns retrofitted with each technique. The analysis found that fiber reinforced polymer jacketing was the most efficient at improving column capacity. Reinforced concrete jacketing was best at reducing inter-story drift ratios of the structure. The document concludes that retrofitting key structural members can reduce inter-story drift to meet code requirements and improve the seismic performance of the building.
ADVANCED ANALYSIS OF SPACE STEEL FRAMESsrinivas cnu
This document discusses advanced analysis methods for designing space steel frames that consider both geometric and material nonlinearities. It describes analyzing frames using stability functions to capture geometric nonlinear effects like p-delta bending, and using fiber models to capture gradual yielding from residual stresses and flexure. The key benefits are more accurate behavior modeling throughout loading using simple analysis methods.
Non Linear Analysis of RCC Building with and Without Shear WallIRJET Journal
This document discusses performing non-linear static (pushover) analysis on reinforced concrete (RC) buildings both with and without shear walls. The analysis is conducted using ETABS software to obtain pushover curves and compare the displacement and base shear in the frames. The objectives are to analyze RC structures with or without shear walls, perform linear and non-linear analysis, and study how parameters like story drift, displacement, and forces are affected by the presence of shear walls. The methodology describes performing linear static analysis, dynamic analysis, and non-linear static pushover analysis on the structures.
Comparison of symmetric and asymmetric steel diagrid structures by non linear...eSAT Journals
Abstract Diagonalized grid structures – “diagrids” - have emerged as one of the most innovative and adaptable approaches to structuring buildings in this millennium. Diagrid is a particular form of space truss, it consists of perimeter grid made up of a series of triangulated truss system. Diagrid is formed by intersecting the diagonal and horizontal components. Construction of multi‐storey building is rapidly increasing throughout the world. Advance in construction technology, materials, structural systems, various analysis and design software have facilitated the growth of various kinds of buildings. Diagrid buildings are emerging as structurally efficient as well as architecturally and aesthetically significant assemblies for tall buildings. Recently these diagrid structural systems have been widely used for tall buildings due to the structural efficiency and aesthetic potential provided by the unique geometric configuration of the system. This paper presents a 12 storey steel diagrid structure which is 36m in height. Symmetric and asymmetric structural configurations of diagrid structures were modelled and analyzed using SAP 2000 by considering Dead load, Live load and Seismic Loads (IS 1893-Part-1, 2002). Then FEMA 356 hinges (auto hinges) are assigned to the same structure and Nonlinear Static (Pushover) analysis is carried out by using seismic load as the pushover load case to find out the performance points that is Immediate Occupancy, Life Safety, and Collapse Prevention of diagrid elements using static pushover curve. At the same time spectral displacement demand & spectral displacement capacity as well as spectral acceleration demand and spectral acceleration capacity is compared to know the adequacy of the design by using ATC capacity spectrum method. Keywords: Diagrid, Pushover analysis, Spectral displacement demand, Spectral displacement capacity, Spectral acceleration demand, Spectral acceleration capacity
Measurements of Geophysical Velocity for Building InspectionAli Osman Öncel
The document describes a study that evaluated the compressive strength of concrete using nondestructive testing methods. Specifically, it used the rebound hammer test, ultrasonic pulse velocity test, and a combined method that uses both. Statistical analysis, including simple and multiple linear regression, was used to develop correlations between the nondestructive test results and actual compressive strengths from cylinder and core samples. The combined method was found to improve the accuracy of estimating compressive strength by taking into account factors that influence each test method differently. Equations derived from the statistical analysis can be used to predict compressive strength on site based on rebound hammer and ultrasonic pulse velocity measurements.
Study of analysis of bus passenger tie rod a revieweSAT Journals
Abstract This paper focuses on the study of buckling load on the Tie rod of steering system that undergoes an axial compression. Because of the external factors like road condition, different driving situations, different road adhesion, traffic conditions, vibrations and sudden jerks are sets up in tie rod. Tie rod generally buckle under the action of compressive force due to the large ratio of tie rod length to its radius of gyration. When it becomes worn out, steering will become more difficult and the vehicle will also typically be pulling or dragging to either side. Thus the aim of the project is to analyze tie rod for to improve the mass and buckling load of tie rod and to find out maximum deformation and stress. Present research is divided in two parts. First, to conduct survey amongst the buses, examine the causes of failure and second is to design and analysis to recommend best possible alternatives of Tie Rod with the aid of advanced design tools like CAD. Tie Rod failure is one of the major problems facing for MSRTC workshop supervisor. Key Words: Buckling Load, Compressive Load, CAD, FEM, MSRTC Bus, Tie Rod etc…
Analysis and study of progressive collapse behaviour of reinforced concrete s...IRJET Journal
This document analyzes the progressive collapse behavior of a 20-story reinforced concrete building with and without outrigger beams. It describes modeling the building in ETABS and performing linear static analysis with two cases of column removal as specified by GSA guidelines. The analysis calculates variations in axial forces of critically affected columns and demand capacity ratios of critically affected beams to compare the structure's performance with and without outrigger beams. Outrigger beams connect the core structure to perimeter columns, providing alternate load paths that help resist progressive collapse upon loss of primary structural members.
IRJET- Seismic Time History Performance of Conventional Multi-Outriggers with...IRJET Journal
This document summarizes a study that analyzed the seismic performance of different configurations of outrigger systems in high-rise buildings using time history analysis. Five 35-story building models were analyzed: 1) bare frame, 2) two outriggers, 3) two outriggers with belt truss, 4) three outriggers, and 5) two outriggers with mega columns. The models were subjected to time history analyses using earthquake records. Results showed that using multiple outriggers and mega columns reduced top story displacements, inter-story drifts, and building period compared to the bare frame model, with two outriggers with mega columns performing the best. Outriggers significantly reduced drift at outrigger levels,
Similar to State of-the-art-non-linear-analysis (20)
Dr. Sean Tan, Head of Data Science, Changi Airport Group
Discover how Changi Airport Group (CAG) leverages graph technologies and generative AI to revolutionize their search capabilities. This session delves into the unique search needs of CAG’s diverse passengers and customers, showcasing how graph data structures enhance the accuracy and relevance of AI-generated search results, mitigating the risk of “hallucinations” and improving the overall customer journey.
LF Energy Webinar: Electrical Grid Modelling and Simulation Through PowSyBl -...DanBrown980551
Do you want to learn how to model and simulate an electrical network from scratch in under an hour?
Then welcome to this PowSyBl workshop, hosted by Rte, the French Transmission System Operator (TSO)!
During the webinar, you will discover the PowSyBl ecosystem as well as handle and study an electrical network through an interactive Python notebook.
PowSyBl is an open source project hosted by LF Energy, which offers a comprehensive set of features for electrical grid modelling and simulation. Among other advanced features, PowSyBl provides:
- A fully editable and extendable library for grid component modelling;
- Visualization tools to display your network;
- Grid simulation tools, such as power flows, security analyses (with or without remedial actions) and sensitivity analyses;
The framework is mostly written in Java, with a Python binding so that Python developers can access PowSyBl functionalities as well.
What you will learn during the webinar:
- For beginners: discover PowSyBl's functionalities through a quick general presentation and the notebook, without needing any expert coding skills;
- For advanced developers: master the skills to efficiently apply PowSyBl functionalities to your real-world scenarios.
Observability Concepts EVERY Developer Should Know -- DeveloperWeek Europe.pdfPaige Cruz
Monitoring and observability aren’t traditionally found in software curriculums and many of us cobble this knowledge together from whatever vendor or ecosystem we were first introduced to and whatever is a part of your current company’s observability stack.
While the dev and ops silo continues to crumble….many organizations still relegate monitoring & observability as the purview of ops, infra and SRE teams. This is a mistake - achieving a highly observable system requires collaboration up and down the stack.
I, a former op, would like to extend an invitation to all application developers to join the observability party will share these foundational concepts to build on:
zkStudyClub - Reef: Fast Succinct Non-Interactive Zero-Knowledge Regex ProofsAlex Pruden
This paper presents Reef, a system for generating publicly verifiable succinct non-interactive zero-knowledge proofs that a committed document matches or does not match a regular expression. We describe applications such as proving the strength of passwords, the provenance of email despite redactions, the validity of oblivious DNS queries, and the existence of mutations in DNA. Reef supports the Perl Compatible Regular Expression syntax, including wildcards, alternation, ranges, capture groups, Kleene star, negations, and lookarounds. Reef introduces a new type of automata, Skipping Alternating Finite Automata (SAFA), that skips irrelevant parts of a document when producing proofs without undermining soundness, and instantiates SAFA with a lookup argument. Our experimental evaluation confirms that Reef can generate proofs for documents with 32M characters; the proofs are small and cheap to verify (under a second).
Paper: https://eprint.iacr.org/2023/1886
In his public lecture, Christian Timmerer provides insights into the fascinating history of video streaming, starting from its humble beginnings before YouTube to the groundbreaking technologies that now dominate platforms like Netflix and ORF ON. Timmerer also presents provocative contributions of his own that have significantly influenced the industry. He concludes by looking at future challenges and invites the audience to join in a discussion.
Why You Should Replace Windows 11 with Nitrux Linux 3.5.0 for enhanced perfor...SOFTTECHHUB
The choice of an operating system plays a pivotal role in shaping our computing experience. For decades, Microsoft's Windows has dominated the market, offering a familiar and widely adopted platform for personal and professional use. However, as technological advancements continue to push the boundaries of innovation, alternative operating systems have emerged, challenging the status quo and offering users a fresh perspective on computing.
One such alternative that has garnered significant attention and acclaim is Nitrux Linux 3.5.0, a sleek, powerful, and user-friendly Linux distribution that promises to redefine the way we interact with our devices. With its focus on performance, security, and customization, Nitrux Linux presents a compelling case for those seeking to break free from the constraints of proprietary software and embrace the freedom and flexibility of open-source computing.
UiPath Test Automation using UiPath Test Suite series, part 5DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 5. In this session, we will cover CI/CD with devops.
Topics covered:
CI/CD with in UiPath
End-to-end overview of CI/CD pipeline with Azure devops
Speaker:
Lyndsey Byblow, Test Suite Sales Engineer @ UiPath, Inc.
Securing your Kubernetes cluster_ a step-by-step guide to success !KatiaHIMEUR1
Today, after several years of existence, an extremely active community and an ultra-dynamic ecosystem, Kubernetes has established itself as the de facto standard in container orchestration. Thanks to a wide range of managed services, it has never been so easy to set up a ready-to-use Kubernetes cluster.
However, this ease of use means that the subject of security in Kubernetes is often left for later, or even neglected. This exposes companies to significant risks.
In this talk, I'll show you step-by-step how to secure your Kubernetes cluster for greater peace of mind and reliability.
Enchancing adoption of Open Source Libraries. A case study on Albumentations.AIVladimir Iglovikov, Ph.D.
Presented by Vladimir Iglovikov:
- https://www.linkedin.com/in/iglovikov/
- https://x.com/viglovikov
- https://www.instagram.com/ternaus/
This presentation delves into the journey of Albumentations.ai, a highly successful open-source library for data augmentation.
Created out of a necessity for superior performance in Kaggle competitions, Albumentations has grown to become a widely used tool among data scientists and machine learning practitioners.
This case study covers various aspects, including:
People: The contributors and community that have supported Albumentations.
Metrics: The success indicators such as downloads, daily active users, GitHub stars, and financial contributions.
Challenges: The hurdles in monetizing open-source projects and measuring user engagement.
Development Practices: Best practices for creating, maintaining, and scaling open-source libraries, including code hygiene, CI/CD, and fast iteration.
Community Building: Strategies for making adoption easy, iterating quickly, and fostering a vibrant, engaged community.
Marketing: Both online and offline marketing tactics, focusing on real, impactful interactions and collaborations.
Mental Health: Maintaining balance and not feeling pressured by user demands.
Key insights include the importance of automation, making the adoption process seamless, and leveraging offline interactions for marketing. The presentation also emphasizes the need for continuous small improvements and building a friendly, inclusive community that contributes to the project's growth.
Vladimir Iglovikov brings his extensive experience as a Kaggle Grandmaster, ex-Staff ML Engineer at Lyft, sharing valuable lessons and practical advice for anyone looking to enhance the adoption of their open-source projects.
Explore more about Albumentations and join the community at:
GitHub: https://github.com/albumentations-team/albumentations
Website: https://albumentations.ai/
LinkedIn: https://www.linkedin.com/company/100504475
Twitter: https://x.com/albumentations
Essentials of Automations: The Art of Triggers and Actions in FMESafe Software
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We’ll kick things off by showcasing the most commonly used event-based triggers, introducing you to various automation workflows like manual triggers, schedules, directory watchers, and more. Plus, see how these elements play out in real scenarios.
Whether you’re tweaking your current setup or building from the ground up, this session will arm you with the tools and insights needed to transform your FME usage into a powerhouse of productivity. Join us to discover effective strategies that simplify complex processes, enhancing your productivity and transforming your data management practices with FME. Let’s turn complexity into clarity and make your workspaces work wonders!
How to Get CNIC Information System with Paksim Ga.pptxdanishmna97
Pakdata Cf is a groundbreaking system designed to streamline and facilitate access to CNIC information. This innovative platform leverages advanced technology to provide users with efficient and secure access to their CNIC details.
UiPath Test Automation using UiPath Test Suite series, part 6DianaGray10
Welcome to UiPath Test Automation using UiPath Test Suite series part 6. In this session, we will cover Test Automation with generative AI and Open AI.
UiPath Test Automation with generative AI and Open AI webinar offers an in-depth exploration of leveraging cutting-edge technologies for test automation within the UiPath platform. Attendees will delve into the integration of generative AI, a test automation solution, with Open AI advanced natural language processing capabilities.
Throughout the session, participants will discover how this synergy empowers testers to automate repetitive tasks, enhance testing accuracy, and expedite the software testing life cycle. Topics covered include the seamless integration process, practical use cases, and the benefits of harnessing AI-driven automation for UiPath testing initiatives. By attending this webinar, testers, and automation professionals can gain valuable insights into harnessing the power of AI to optimize their test automation workflows within the UiPath ecosystem, ultimately driving efficiency and quality in software development processes.
What will you get from this session?
1. Insights into integrating generative AI.
2. Understanding how this integration enhances test automation within the UiPath platform
3. Practical demonstrations
4. Exploration of real-world use cases illustrating the benefits of AI-driven test automation for UiPath
Topics covered:
What is generative AI
Test Automation with generative AI and Open AI.
UiPath integration with generative AI
Speaker:
Deepak Rai, Automation Practice Lead, Boundaryless Group and UiPath MVP
Full-RAG: A modern architecture for hyper-personalizationZilliz
Mike Del Balso, CEO & Co-Founder at Tecton, presents "Full RAG," a novel approach to AI recommendation systems, aiming to push beyond the limitations of traditional models through a deep integration of contextual insights and real-time data, leveraging the Retrieval-Augmented Generation architecture. This talk will outline Full RAG's potential to significantly enhance personalization, address engineering challenges such as data management and model training, and introduce data enrichment with reranking as a key solution. Attendees will gain crucial insights into the importance of hyperpersonalization in AI, the capabilities of Full RAG for advanced personalization, and strategies for managing complex data integrations for deploying cutting-edge AI solutions.
Threats to mobile devices are more prevalent and increasing in scope and complexity. Users of mobile devices desire to take full advantage of the features
available on those devices, but many of the features provide convenience and capability but sacrifice security. This best practices guide outlines steps the users can take to better protect personal devices and information.
GDG Cloud Southlake #33: Boule & Rebala: Effective AppSec in SDLC using Deplo...James Anderson
Effective Application Security in Software Delivery lifecycle using Deployment Firewall and DBOM
The modern software delivery process (or the CI/CD process) includes many tools, distributed teams, open-source code, and cloud platforms. Constant focus on speed to release software to market, along with the traditional slow and manual security checks has caused gaps in continuous security as an important piece in the software supply chain. Today organizations feel more susceptible to external and internal cyber threats due to the vast attack surface in their applications supply chain and the lack of end-to-end governance and risk management.
The software team must secure its software delivery process to avoid vulnerability and security breaches. This needs to be achieved with existing tool chains and without extensive rework of the delivery processes. This talk will present strategies and techniques for providing visibility into the true risk of the existing vulnerabilities, preventing the introduction of security issues in the software, resolving vulnerabilities in production environments quickly, and capturing the deployment bill of materials (DBOM).
Speakers:
Bob Boule
Robert Boule is a technology enthusiast with PASSION for technology and making things work along with a knack for helping others understand how things work. He comes with around 20 years of solution engineering experience in application security, software continuous delivery, and SaaS platforms. He is known for his dynamic presentations in CI/CD and application security integrated in software delivery lifecycle.
Gopinath Rebala
Gopinath Rebala is the CTO of OpsMx, where he has overall responsibility for the machine learning and data processing architectures for Secure Software Delivery. Gopi also has a strong connection with our customers, leading design and architecture for strategic implementations. Gopi is a frequent speaker and well-known leader in continuous delivery and integrating security into software delivery.
3. · · · · · 17
4.2.4 Load· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·
· · · · · · · · 17
4.3 Design Consideration· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·
· · · · · · ·18
4.3.1 Load-carrying capacity· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·
· · · · · ·18
4.3.2 Resistance factor· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·
· · · · · ·19
4.3.3 Serviceability limit· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·
· · · · · · 19
4.3.4 Ductility requirement· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·
· · · · · · 20
REFERENCES · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·
· · · · · · · 21
1. INTRODUCTION
The steel design methods used in the U.S. are Allowable Stress Design (ASD), Plastic Design
(PD), and Load and Resistance Factor Design (LRFD). In ASD, the stress computation is based on a
first-order elastic analysis, and the geometric nonlinear effects are implicitly accounted for in the
member design equations. In PD, a first-order plastic-hinge analysis is used in the structural analysis.
Plastic design allows inelastic force redistribution throughout the structural system. Since geometric
nonlinearity and gradual yielding effects are not accounted for in the analysis of plastic design, they
are approximated in member design equations. In LRFD, a first-order elastic analysis with
amplification factors or a direct second-order elastic analysis is used to account for geometric
nonlinearity, and the ultimate strength of beam-column members is implicitly reflected in the design
interaction equations. All three design methods require separate member capacity checks including
the calculation of the K-factor. This design approach is marked in Fig. 1 as the indirect analysis and
ii
4. design method.
In the current AISC-LRFD Specification (AISC, 1994), first-order elastic analysis or second-
order elastic analysis is used to analyze a structural system. In using first-order elastic analysis, the
first-order moment is amplified by B1 and B2 factors to account for second-order effects. In the
Specification, the members are isolated from a structural system, and they are then designed by the
member strength curves and interaction equations as given by the Specifications, which implicitly
account for the effects of second-order, inelasticity, residual stresses, and geometric imperfections
(Chen and Lui, 1986). The column curve and beam curve were developed by a curve-fit to both
theoretical solutions and experimental data, while the beam-column interaction equations were
determined by a curve-fit to the so-called "exact" plastic-zone solutions generated by Kanchanalai
(1977). In order to account for the influence of a structural system on the strength of individual
members, the effective length factor is used as illustrated in Fig. 2.
The effective length method generally provides a good design of framed structures.
However, several difficulties are associated with the use of the effective length method as follows:
(1) The effective length approach cannot accurately account for the interaction between the
structural system and its members. This is because the interaction in a large structural system is too
complex to be represented by the simple effective length factor K. As a result, this method cannot
accurately predict the actual required strengths of its framed members.
(2) The effective length method cannot capture the inelastic redistributions of internal forces in a
structural system, since the first-order elastic analysis with B1 and B2 factors accounts only for
second-order effects but not the inelastic redistribution of internal forces. The effective length
method provides a conservative estimation of the ultimate load-carrying capacity of a large structural
system.
(3) The effective length method cannot predict the failure modes of a structural system subject to a
given load. This is because the LRFD interaction equation does not provide any information about
2
5. failure modes of a structural system at the factored loads.
(4) The effective length method is not user-friendly for a computer-based design.
(5) The effective length method requires a time-consuming process of separate member capacity
checks involving the calculation of K-factors.
With the development of computer technology, two aspects, the stability of separate members,
and the stability of the structure as a whole, can be treated rigorously for the determination of the
maximum strength of the structures. This design approach is marked in Fig. 1 as the direct analysis
and design method (Kim and Chen, 1996a-b). The development of the direct approach to design is
called “Advanced Analysis” or more specifically, “Second-Order Inelastic Analysis for Frame
Design.” In this direct approach, there is no need to compute the effective length factor, since
separate member capacity checks encompassed by the specification equations are not required. With
the current available computing technology, it is feasible to employ nonlinear inelastic analysis
techniques for direct frame design. This method has been considered impractical for design office
use in the past.
Over the past 20 years, extensive research has been made to develop and validate several
nonlinear inelastic analysis methods. The purpose of this paper is to review recent efforts to develop
various nonlinear inelastic analyses ranging from a simple elastic-plastic to rigorous plastic-zone
analysis for frame design. Emphasis in this review is design application of nonlinear inelastic
analysis. This paper also summarizes reports of experimental studies to provide inelastic nonlinear
behavior of framed structures. The analysis and design principle using nonlinear inelastic analysis
are also addressed.
2. NONLINEAR INELASTIC ANALYSIS
3
6. Five different types of nonlinear inelastic analysis methods are discussed in the following:
(1) Plastic-zone method
(2) Quasi-plastic hinge method
(3) Elastic-plastic hinge method
(4) Notional-load plastic hinge method
(5) Refined-plastic hinge method
These different methods are based on the degree of refinement in representing the plastic
yielding effects. The plastic-zone method uses the greatest refinement while the elastic-plastic hinge
method allows a drastic simplification. The quasi-plastic hinge method is somewhere in between
these two methods. The notional-load plastic hinge method and the refined-plastic hinge method are
an improvement on the elastic-plastic hinge method for approximating real behavior of structures.
The load-deformation characteristics of the plastic analysis methods are illustrated in Fig. 3, while the
spread of plasticity is illustrated schematically in Fig. 4.
2.1 Plastic-Zone Method
In the plastic-zone method, frame members are discretized into finite elements, and the cross-
section of each finite element is subdivided into many fibers shown in Fig. 5. The deflection at each
division point along a member is obtained by numerical integration. The incremental load-deflection
response at each loading step, which updates the geometry, captures the second-order effects. The
residual stress in each fiber is assumed constant since the fibers are small enough. The stress state at
each fiber can be explicitly traced so the gradual spread of yielding can be captured. The plastic-zone
analysis eliminates the need for separate member capacity checks since it explicitly accounts for
second-order effects, spread of plasticity, and residual stress. As a result, the plastic-zone solution is
known as an "exact solution." The AISC-LRFD beam-column equations were established in part
based upon a curve-fit to the "exact" strength curves obtained from the plastic-zone analysis by
Kanchanalai (1977).
4
7. There are two types of plastic-zone analyses. The first involves the use of three-dimensional
finite shell elements in which the elastic constitutive matrix in the usual incremental stress-strain
relations, is replaced by an elastic-plastic constitutive matrix when yielding is detected. Based on a
deformation theory of plasticity, the effects of combined normal and shear stresses may be accounted
for. This analysis requires modeling of structures using a large number of finite three-dimensional
shell elements and numerical integration for the evaluation of the elastic-plastic stiffness matrix.
The three-dimensional spread-of-plasticity analysis when combined with second-order theory which
deals with frame stability is computational intensive and, therefore, best suited for analyzing small-
scale structures, or if the detailed solutions for member local instability and yielding behavior are
required. Since a detailed analysis of local effects in realistic building frames is not common
practice in engineering design, this approach is considered too expensive for practical use.
The second approach for second-order plastic-zone analysis is based on the use of beam-
column theory, in which the member is discretized into line segments, and the cross-section of each
segment is subdivided into finite elements. Inelasticity is modeled considering normal stress only.
When the computed stress at the centroid of any fiber reaches the uniaxial normal strength of the
material, the fiber is considered to have yielded. Also, compatibility is treated by assuming that full
continuity is retained throughout the volume of the structure in the same manner as elastic range
calculations. Although quite sharp curvature may exist in the vicinity of inelastic portions of the
structure, “plastic hinges” can never develop. In plastic-zone analysis, the calculation of forces and
deformations in the structure after yielding requires an iterative trial-and-error process because of the
nonlinearity of the load-deformation response, and the change in cross-section effective stiffness in
inelastic regions associated with the increase in the applied loads and the change in structural
geometry. Although most plastic-zone analysis methods have been developed for planar analyses
(Clarke et al., 1992; White, 1985; Vogel, 1985; El-Zanaty et al., 1980; Alvarez and Birnstiel, 1967)
three-dimensional plastic-zone techniques are also available (Wang, 1988; Chen and Atsuta, 1977).
5
8. A plastic-zone analysis that includes the spread of plasticity, residual stresses, initial
geometric imperfections, and any other significant second-order effects, would eliminate the need for
checking individual member capacities in the frame. Therefore, this type of method is classified as
nonlinear inelastic inelastic analysis in which the checking of beam-column interaction equations is
not required. In fact, the member interaction equations in modern limit-states specifications were
developed, in part, by curve-fit to results from this type of analysis. In reality, some significant
behaviors such as joint and connection’s performances tend to defy precise numerical and analytical
modeling. In such cases, a simpler method of analysis that adequately represents the significant
behavior would be sufficient for engineering application.
Whereas the plastic-zone solution is regarded as an "exact solution," the method may not be
used in daily engineering design, because it is too intensive in computation. Its applications are
limited to (ECCS, 1984):
(1) The study of detailed structural behavior
(2) Verifying the accuracy of simplified methods
(3) Providing comparison with experimental results
(4) Deriving design methods or generating charts for practical use
(5) Applying for special design problems
2. 2 Quasi-Plastic Hinge Method
The quasi-plastic hinge method developed by Attala (1994) is an intermediate approach
between the plastic-zone and the elastic-plastic hinge methods. It requires less computation but its
results are very similar to those of plastic-zone method. For this reason, it is called a quasi-plastic
hinge method.
An element, developed from equilibrium, kinematic, and constitutive relationships, accounts
for gradual plastification under combined bending and axial force. Inelastic force-strain model of
6
9. the cross-section is developed by fitting nonlinear equations to data of the moment-axial force-
curvature response. Using the inelastic cross-section model, flexibility coefficients for the full
member are obtained by successive integrations along its length. An inelastic-element stiffness
matrix is obtained by the use of the incremental flexibility relationships.
Initial yield and full plastification surface are used to analytically represent gradual yielding
effect of the cross-section. Ketter’s residual stress pattern (1955) is used to determine an initial yield
surface. Ketter’s pattern has peak compressive residual stresses at the flange tips equal to 0.3Fy with
a linear transition of stress from the flange tips to the web-joint and constant tensile stress through the
web. A fully plastic surface is generated by calibration to a plastic-zone solution (Sanz-Picon, 1992).
The parameters of the full plastification equation are determined by a curve-fit procedure.
This method predicts strengths with an error less than 5% compared with the plastic-zone
method for a wide range of case studies. The accuracy of this method is thus compatible with the
plastic-zone method and less computational effort is necessary.
However, it is difficult to extend this method to three-dimensional analysis since the
formulation is based on flexibility relationships. As a result, it does not meet one of the
requirements of Αnonlinear inelastic analysis≅ of the SSRC task force report (1993), which states
ΑThe model should be readily extensible to three-dimensional analysis. That is, the framework of
the model should accommodate the formulation of three-dimensional elements.≅ Moreover, this
model does eliminate the necessity of the refined model through the cross-section but still requires
many elements along the member.
2. 3 Elastic-Plastic Hinge Method
A more simple and efficient approach for representing inelasticity in frames is the elastic-
plastic hinge method. It assumes that the element remains elastic except at its ends where zero-
length plastic hinges form. This method accounts for inelasticity but not the spread of yielding or
7
10. plasticity at sections nor the residual stress effect between two plastic hinges.
The elastic-plastic hinge methods may be divided into; first-order and second-order plastic
analyses. For first-order elastic-plastic hinge analysis, the nonlinear geometric effects are neglected,
and not considered in the formulation of the equilibrium equations. As a result, the method predicts
the same ultimate load as conventional rigid-plastic analyses.
In second-order elastic-plastic hinge analysis, the deformed structural geometry is considered.
The simple way to account for the geometric nonlinearity is to use the stability function which enables
only one beam-column element per a member to capture the second-order effect. This provides an
efficient and economical method of frame analysis, and has a clear advantage over the plastic-zone
method. This is particularly true for structures in which the axial force in component members is
small and the dominated behavior is bending. In such cases, second-order elastic-plastic hinge
analysis may be used to describe the inelastic behavior sufficiently, assuming that lateral-torsional and
local buckling modes of failure are not prevented (Liew, 1992).
The second-order elastic-plastic hinge analysis is only an approximate method. When used
to analyze a single beam-column element subject to combined axial load and bending moment, it may
overestimate the strength and stiffness of the element in the inelastic range. Although elastic-plastic
hinge approaches provide essentially the same load-displacement predictions as plastic-zone methods
for many frame problems, they may not be classified as nonlinear inelastic analysis methods in
general (Liew et al., 1994; Liew and Chen, 1991; White, 1993).
However, research by Ziemian (Ziemian et al., 1990; Ziemian, 1990) has shown that the
elastic-plastic hinge analysis can be classified as an advanced inelastic analysis since it is accurate for
matching the strength and load-displacement response of several building frames from plastic-zone
analysis. Many cases considered in Ziemian=s work, especially when the axial load is less than
0.5Py, are not sensitive benchmarks for determining the accuracy and the possible limitations of the
elastic-plastic hinge method. Therefore, suitable benchmark problems should be used to provide a
8
11. more in-depth study of the qualities and limitations of second-order elastic-plastic hinge method
before it can be accepted as a legitimate tool in the design of steel structures.
For slender members whose dominant mode of failure is elastic instability, the method provides good
results when compared with plastic-zone solutions. However, for stocky members with significant
yielding, the plastic-hinge method over-predicts the actual strength and stiffness of members due to
the gradual stiffness reduction as the spread of plasticity increases in an actual member (Liew and
Chen, 1991; Liew et al., 1991; White et al., 1991). As a result, considerable refinements must be
made before it can be used for analysis of a wide range of framed structures.
2. 4 Notional-Load Plastic-Hinge Method
One approach to advance the use of second-order elastic-plastic hinge analysis for frame
design is to specify artificially large values of frame imperfections (i.e., initial out-of-plumbness).
This is the approach adopted by EC3 (1990) for frame design using second-order analysis. In
addition to accounting for the standard erection tolerance for out-of-plumbness, these artificial large
imperfections intend to account for the effect of residual stresses, frame imperfections, and distributed
plasticity not considered in frame analysis. The geometric imperfections adopted by EC3 are a
maximum out-of-plumbness of Ψ0 = 1/200 for an unbraced frame, but no maximum out-of-
straightness value recommended for a braced member as shown in Fig. 6.
The notional load plastic hinge approach is similar in concept to the “enlarged” geometric
imperfection approach of the EC3. The ECCS (1984, 1991), the Canadian Standard (1989, 1994),
and the Australian Standard (1990) allow to use this technique. The notional-load approach uses
equivalent lateral loads to approximate the effect of member imperfections and distributed plasticity.
In the ECCS, the exaggerated notional loads of 0.5 % times gravity loads are used to avoid over-
predicting the strength of the member as does the elastic-plastic hinge method. The application of
these notional loads to several example frames is illustrated in Fig. 7. Liew' s research (1992) shows
9
12. that this method under-predicts the strength by more than 20% in the various leaning column frames
and over-predicts the strength up to 10% in the isolated beam-columns subject to the axial forces and
bending moments. As a result, modification of this approach is required before it may be used in
design applications.
2. 5 Refined Plastic-Hinge Method
In recent work by Abdel-Ghaffar et al. (1991), Al-Mashary and Chen (1991), King, et al.
(1991), Liew and Chen (1991), Liew et al. (1993a-b), White et al. (1991), Kim (1996), Kim and Chen
(1996), Chen and Kim (1997), Kim and Chen (1997), Kim et al (2000) and among others, an inelastic
analysis approach, based on simple refinements of the elastic-plastic hinge model, has been proposed
for plane frame analysis. It represents the effect of distributed plasticity through the cross-section,
assuming that the plastic hinge stiffness degradation is smooth. The inelastic behavior of the
member is modeled in terms of member force instead of the detailed level of stresses and strains as
used in the plastic-zone analysis model. The principal merits of the refined-plastic hinge model are
that it is as simple and efficient as the elastic-plastic hinge analysis approach, and it is sufficiently
accurate for the assessment of strength and stability of a structural system and its component members.
The refined plastic-hinge method is based on simple modifications of the elastic-plastic hinge
method. Two modifications are made to account for the gradual section stiffness degradation at the
plastic hinge locations as well as gradual member stiffness degradation between the two plastic hinges.
Herein, the section stiffness degradation function is adopted to reflect the gradual yielding effect in
forming plastic hinges. Then, the tangent modulus concept is used to capture the residual stress
effect along the member between two plastic hinges. As a result, the refined plastic-hinge method
retains the efficiency and simplicity of the plastic hinge method without overestimating the strength
and stiffness of a member.
In the recent work by Liew (1992), the LRFD tangent modulus is used to account for both the
10
13. effect of residual stresses and geometric imperfections. This model does not account for geometric
imperfections when P/Py is less than 0.39, because the LRFD tangent modulus is identical to the
elastic modulus in this range. As a result, the approach over-predicts the column strength by more
than 5% when KL/r of the column is greater than 85 for yield stresses at 36 ksi, and when KL/r of the
column is greater than 70 for yield stresses at 50 ksi. The LFRD Et may not be an appropriate model
to be used for nonlinear inelastic analysis (Kim, 1996; Kim and Chen, 1996).
The CRC tangent modulus in Liew's work (1992) only accounts for the effect of residual
stresses. It over-predicts the strength of members by about 20% compared to the conventional
LRFD solutions, because the modulus does not account for the effect of geometric imperfections.
However, in the CRC tangent modulus model, different members with different residual stresses can
be incorporated since the effect of geometric imperfections is considered separately. As a result,
CRC tangent modulus is used in refined plastic analyses.
Second-order inelastic analysis methods for the three-dimensional structure have been
developed by Orbison (1982), Prakash and Powell (1993), Liew and Tang (1998), Kim et al (2001),
Kim and Choi (2001) and Kim et al (2001). Orbison's method is an elastic-plastic hinge analysis
without considering shear deformations. The material nonlinearity is considered by the tangent
modulus Et and the geometric nonlinearity is by a geometric stiffness matrix. Orbison's method,
however, underestimates the yielding strength up to 7% in stocky members subjected to axial force
only. DRAIN-3DX developed by Prakash and Powell is a modified version of plastic hinge methods.
The material nonlinearity is considered by the stress-strain relationship of the fibers in a section. The
geometric nonlinearity caused by axial force is considered by the use of the geometric stiffness matrix,
but the nonlinearity caused by the interaction between the axial force and the bending moment is not
considered. This method overestimates the strength and stiffness of the member subjected to
significant axial force. Liew and Tang's method is a refined plastic hinge analysis. The effect of
residual stresses is taken into account in conventional beam-column finite element modelling.
11
14. Nonlinear material behavior is taken into account by calibration of inelastic parameters describing the
yield and bounding surfaces. Liew and Tang's method, however, underestimates the yielding strength
up to 7% in stocky member subjected to axial force only.
Against this background, it can be concluded that the refined-plastic hinge method strikes a
balance between the requirements for realistic representation of frame behavior and for ease of use.
It is considered that in both theses respects, the method is satisfactory for general practical use.
3. NONLINEAR INELASTIC EXPERIMENTS
Experimental studies to capture inelastic nonlinear behavior of framed structures are
summarized. The frames riviewed herein were tested by Kanchanalai(1977), Yarimci(1966),
Avery(1999), Wakabayashi(1972), Harrison(1964) and Kim and Kang(2001).
3.1 Kanchanalai’s Two-Bay Frames
Three two-bay full-size frames were tested to verify the Plastic-zone analysis(Kanchanalai,
1977). The dimensions and members of Frame 2 among these frames are shown in Fig. 8. The
material properties of the members are summerized in Table 1. The frames were designed to behave
equivalently to a one-story two-bay and could be tested on the floor. Supports were provided only at
the top and bottom of the interior column member. All frames were bent with respect to the week
axis in order to avoid out-of-plane buckling. In Frame 2, all columns were loaded simultaneously up
to about 70kips, corresponding to points 2-11 in Fig. 9. Then, only the axial load on the interior
column was increased up to point 17, where the frame reached its instability limit load of 233.6 kips.
Comparisons of the test results with the plastic zone theory are shown in Fig. 9. In general, good
agreements are observed.
12
15. 3.2 Yarimci’s Three-Story Frames
An experimental research study was conducted at Lehigh University for three full-size frames
(Yarimci, 1966). Fig. 10 shows dimensions and loads conditions of Frame C among the three frames.
To investigate and compare the mechanical properties of the members with nominal values, Yarimci
conducted a series of seven beam tests. The results of these tests are summarized in Table 2. The
beams were welded to the columns and designed so as to behave elastically in the worst loading
condition: the flexibility of the connections was eliminated from a factor which affects the strength of
the frames. The frames were sandwiched and supported laterally by two parallel auxiliary frames
preventing out-of-plane buckling. All members were bent in strong axis. The result of test is
shown in Fig. 11 for Frame C. The load deflection behavior at the first and third story is shown in
Fig. 11.
3.3 Avery and Mahendran’s Large-Scale Testing of Steel Frame Structures
A series of four tests was conducted by Avery and Mahendran(1999). Each of the four
frames could be classified as a two-dimensional, single-bay, single-story, large-scale sway frame with
full lateral restraint and rigid joints, as shown in Fig. 12. In Frame 2, Non-compact I-
sections(310UB32.0) of Grade 300 steel(nominal yield stress=320MPa)was used. This section was
selected as one of the standard hot-rolled I-sections mostly affected by local buckling. The
dimensions, material properties, and section properties used in Frames 2 are listed in Table 3. The
vertical and horizontal loads were applied simultaneously in a ratio of approximately four times
greater than the horizontal reaction measured by the load cell. The frame failed by in-plane instability
due to a reduced stiffness caused by yielding and P-Δ effect. The horizontal reaction force and the
measured relative in-plane horizontal displacement of the right hand column for test Frame 2 are
related in Fig. 13.
13
16. 3.4 Wakabayashi’s One-Quarter Scaled Test of Portal Frames
Two-series of test were conducted for a one-story frame and a two-story frame by
Wakabayashi et al(1972). Configurations of the two-story frame are shown in Fig. 14. The
nominal dimensions of members are H-100×100×6×8 for columns and H-100×50×4×6 for beams.
The specimens consist of rolled H-shapes. The connections were welded and stiffened to prevent
local buckling in the joint panels. To prevent the out-of-plane buckling, two of the same specimens
were set in parallel and connected at the joints and the mid-length of the members. In the other
words, twin specimens were tested simultaneously. Measured Material and sectional properties of
members are listed in Table 4.
The vertical load was first applied at the top of four columns by a fixed testing machine.
The parallel twin specimens were loaded simultaneously. Then, the horizontal load at the top of
frame was increased gradually. When the frame swayed by the horizontal loading jack followed a
horizontal movement so that vertical loading points could be kept on the center of the columns. The
loads were measured by the load cells which were installed between the hydraulic jacks and the
specimen.
The load-deflection curves of the two-story frames are shown in Fig. 15. Comparisons of a
series of test show the effects of axial force and stiffness of the beam on the frame behavior. The
larger the axial force in columns and the smaller the stiffness of the beam, the more unstable the
frames become.
3.5 Harrison’s Space Frame Test
The equilateral triangular space frame depicted in Fig. 3 was tested by Harrison(1964) in the
J.W.Roderick Laboratory for Materials and Structures at the University of Sydney. Configuration of the
frame is shown in Fig. 16. Measured dimensions and material properties are listed in Table 5. A
14
17. horizontal load(H) is applied on the top of the column and a vertical load of 1.3H is applied at mid
span of the beam.
It can be seen from Fig. 17 that, compared to the experimental results, the plastic-zone
analysis predicted a slightly stiffer response of the space frame under the applied loads. As the
column bases of the space frame were welded to steel plates clamped to steel joists(Harrison 1964),
the more flexible response measured in the laboratory test might have been caused by the flexibility of
the joist flanges.
3.6 Kim’s 3D Frame Test
Two-series of test were conducted for space steel frame subjected proportional loads shown
in Fig 18 and space steel frame subjected proportional loads shown in Fig.
19 by Kim and Kang(2001). Hot-rolled I-section was used for all three frames. Nominal dimension of
the section was H-150×150×7×10 commonly used in Korea. The dimensions and properties of the
section are listed in Table 6. The section is compact so that it is not susceptible to local buckling.
For proportional loads test, The vertical loads were applied on the top of the four columns,
and the horizontal loads were applied on the column ② and ④ at the second floor level of the test
frame. The vertical loads were slowly increased until the system could not resist any more loads.
The horizontal loads were automatically increased according to the specified load ratio for each test
frame controlled by the computer system.
For non-proportional loads test, The vertical loads were applied on the top of the four
columns, and the horizontal load was applied on the column ② at the second floor level of the test
frame. The vertical loads were first increased 680 kN and maintained during the experiment. The
horizontal load was slowly increased until the test frame could not resist any more loads.
Fig. 20. and Fig. 21. show load-displacement curve for test frames. The obtained results
from 3D non-linear analysis and AISC-LRFD method were compared with experimental data.
ABAQUS, one of mostly widely used and accepted commercial finite element analysis program, was
15
18. used. Load carrying capacities obtained by the experiment and AISC-LRFD method are compared
in Table 7 and 8. The results showed that the AISC-LRFD capacities were approximately 25 percent
conservative for frame subjected to proportional loads test and 28 percent conservative for non-
proportional loads test. This difference is derived from the fact that the AISC-LRFD approach does
not consider the inelastic moment redistribution, but the experiment includes the inelastic
redistribution effect.
4. DESIGN USING NONLINEAR INELASTIC ANALYSIS
4.1 Design Format
Nonlinear inelastic analysis follows the format of Load and Resistance Factor Design. In
AISC-LRFD(1994), the factored load effect does not exceed the factored nominal resistance of
structure. Two kinds of factors are used: one is applied to loads, the other to resistances. The load
and resistance factor design has the format
η ∑ γ iQi ≤ φ Rn (1)
where Rn = nominal resistance of the structural member, Qi = force effect, φ = resistance
factor, γ i = load factor corresponding to Qi , η = a factor relating to ductility, redundancy, and
operational importance.
The main difference between current LRFD method and nonlinear inelastic analysis method is that the
right side of Eq. (1), ( φ Rn ) in the LRFD method is the resistance or strength of the component of a
structural system, but in the nonlinear inelastic analysis method, it represents the resistance or the
16
19. load-carrying capacity of the whole structural system. In the nonlinear inelastic analysis method, the
load-carrying capacity is obtained from applying incremental loads until a structural system reaches
its strength limit state such as yielding or buckling. The left-hand side of Eq. (1), ( η ∑γ Q )
i i
represents the member forces in the LRFD method, but the applied load on the structural system in the
nonlinear inelastic analysis method.
4.2 Modeling Consideration
4.2.1 Sections
The AISC-LRFD Specification uses only one column curve for rolled and welded sections of
W, WT, and HP shapes, pipe, and structural tubing (AISC, 1994). The Specification also uses same
interaction equations for doubly and singly symmetric members including W, WT, and HP shapes,
pipe and structural tubing, even though the interaction equations were developed on the basis of W
shapes by Kanchanalai (1977).
The proposed analysis was developed by calibration with the LRFD column curve. To this
end, it is concluded that the proposed methods can be used for various rolled and welded sections
including W, WT, and HP shapes, pipe, and structural tubing without further modifications.
4.2.2 Structural members
An important consideration in making this nonlinear inelastic analysis practical is the
required number of elements for a member in order to predict realistically the behavior of frames. A
sensitivity study of nonlinear inelastic analysis for two-dimensional frames was performed on the
required number of elements (Kim and Chen, 1998). Two-element model adequately predicted the
17
20. strength of a two-dimensional member. This rule may be used for modeling a three-dimensional
member.
4.2.3 Geometric imperfection
The magnitudes of geometric imperfections are selected as ψ = 2 1,000 for unbraced
frames and ψ = 1 1, 000 for braced frames. To model a parabolic out-of-straightness in the member,
two-element model with maximum initial deflection at the mid-height of a member adequately
captures imperfection effects. It is concluded that practical nonlinear inelastic analysis is
computationally efficient. The pattern of geometric imperfections is assumed to be the same as the
elastic first order deflected shape.
4.2.4 Load
1) Proportional loading
In the proposed nonlinear inelastic analysis, the gravity and lateral loads should be applied
simultaneously, since it does not account for unloading. As a result, the method under-predicts the
strength of frames subjected to sequential loads, large gravity loads first and then lateral loads. It is,
however, justified for the practical design since the development of the LRFD interaction equations
was also based on strength curves subjected to simultaneous loading and the current LRFD elastic
analysis uses the proportional loading rather than the sequential loading.
2) Incremental loading
It is necessary, in an nonlinear inelastic analysis, to input each increment load (not the total
loads) to trace nonlinear load-displacement behavior. The incremental loading process can be
achieved by scaling down the combined factored loads by a number between 20 and 50. For a
18
21. highly redundant structure, dividing by about 20 is recommended and for a nearly statically
determinate structure, the incremental load may be factored down by 50. One may choose a number
between 20 and 50 to reflect the redundancy of a particular structure. Since a highly redundant
structure has the potential to form many plastic hinges and the applied load (i.e. the smaller scaling
number) may be used.
4.3 Design Consideration
4.3.1 Load-carrying capacity
The elastic analysis method does not capture the inelastic redistribution of internal forces
throughout a structural system, since the first-order forces, even with the B1 and B2 factors,
account for the second-order geometric effect but not the inelastic redistributions of internal forces.
The method may provide a conservative estimation of the ultimate load-carrying capacity. Nonlinear
inelastic analysis, however, directly considers force redistribution due to material yielding and thus
allows smaller member sizes to be selected. This is particularly beneficial in highly indeterminate
steel frames. Because consideration at force redistribution may not always be desirable, the two
approaches (including and excluding inelastic force redistribution) can be used. First, the load-
carrying capacity, including the effect of inelastic force redistribution, is obtained from the final
loading step (limit state) given by the computer program. Secondly, the load-carrying capacity
without the inelastic force redistribution is obtained by extracting that force sustained when the first
member yield or buckled. Generally, nonlinear inelastic analysis predicts the same member size as the
LRFD method when force redistribution is not considered.
4.3.2 Resistance factor
19
22. AISC-LRFD specifies the resistance factors of 0.85 and 0.9 for axial and flexural strength of
a member, respectively. The proposed method uses a system-level resistance which is different from
AISC-LRFD specification using member level resistance factors. When a structural system collapses
by forming plastic mechanism, the resistance factor of 0.9 is used since the dominent behavior is
flexure. When a structural system collapses by member buckling, the resistance factor of 0.85 is used
since the dominent behavior is compression.
4.3.3 Serviceability limit
According to the ASCE Ad Hoc Committee on Serviceability report (Ad Hoc Committee,
1986), the normally accepted range of overall drift limits for building is 1 750 to 1 250 times the
building height, H , with a typical value of H 400 . The general limits on the interstory drift are
1 500 to 1 200 times the story height. Based on the studies by the Ad Hoc Committee (1986), and
by Ellingwood (1989), the deflection limits for girder and story are selected as
• Floor girder live load deflection : H 360
• Roof girder deflection : H 240
• Lateral drift : H 400 for wind load
• Interstory drift : H 300 for wind load
At service load levels, no plastic hinges are allowed to occur in order to avoid permanent
deformations under service loads.
4.3.4 Ductility requirement
Adequate rotation capacity is required for members to develop their full plastic moment
capacity. This is achieved when members are adequately braced and their cross-sections are compact.
20
23. The limits for lateral unbraced lengths and compact sections are explicitly defined in AISC-LRFD
(1994).
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25
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TABLE 1. Summary of Tension Coupon Tests
Member σy ,* y ,st Est σult Elongation
Section Specimen
number ksi ×10-5 ×10-5 ksi ksi in 8 in, %
W8×17 Flange 37.9 128 1140 442 62.4 28.2
C1A
(A36- Flange 37.7 127 1378 356 - 29.7
C1C
70A) Web 40.6 137 2450 345 61.7 32.9
M4×13 Flange 48.5 164 1203 406 69.6 26.6
B1,B2
(A572- Flange 48.6 164 1062 399 69.9 27.2
B3,B4
73) Web 50.1 169 2228 323 69.5 26.7
C1B and C2B were not tested
,*y= Φy/E(E=29,500ksi)
TABLE 2. Measured Properties of Beam and Column Section
Handbook Measured Handbook Measured
Frame Section EI EI Mp MP
2 4
(kip-in ×10 ) (kip-in2×104) (kip-in) (kip-in)
C 12B16.5 310 271 742 845
C 10B15 203 190 576 635
C 6WF15 158 165 686 760
TABLE 3. Dimensions and Properties of Members
Test Section D br tr tw r1 Ag I S σy
26
29. frame (mm) (mm) (mm) (mm) (mm) (mm2) (106mm4) (104mm3) Flange Web
2 310UB32 298 149 8.0 5.5 13.0 4080 63.2 475 360 395
TABLE 4. Actual Section Properties of One-Quarter Scaled Frames
A I Z Zp σy
(cm2) (cm4) (cm3) (cm3) (t/cm2)
Column 21.8 391 77.4 88.5 2.64
Beam 10.6 177 35.0 40.6 3.04
TABLE 5. Dimensions and Material Properties of Equilateral Triangular Space Frame
L D T E G σy(ksi)
(in) (in) (in) (ksi) (ksi) Column Beam
All members 48 1.682 0.176 28800 11520 30.6 31.1
TABLE 6. Dimensions and Properties of Section H-150 × 150 × 7 × 10 Used in the Frame
Moment of Moment of
Thickness Thickness Radius of Axial Area
Height Width Inertia about X Inertia about Y
of Flange of Web Fillet
Axis Axis
H B tf Ag
tw r1
(mm )
IX IY
(mm) (mm) (mm) (mm) (mm) (10 mm ) (10 )
2
6 4 6
mm 4
Nominal 150 150 10 7 11 4014 16.40 5.63
Measured Column 152.3 149.9 10.2 6.75 - 4053 17.20 5.74
Beam 149.1 150.0 9.2 6.50 - 3713 15.14 5.18
TABLE 7. Comparison of Experimental and Design Load Carrying Capacity
(a) Experiment (b) Analysis (c) AISC-LRFD design (b)/(a) (c)/(a)
P 612.0 612.0 443.5 1.0000 0.7247
H 169.2 175.5 122.6 1.0372 0.7246
TABLE 8. Comparison of Experimental and Design Load Carrying Capacities
27
31. FIG. 2. Interaction between A Structural System and Its Component Members
FIG. 3. Load-Deformation Characteristics of Plastic Analysis Methods
29
32. FIG. 4. Concept of Spread of Plasticity for Various Advanced Analysis Methods
FIG. 5. Model of Plastic-Zone Analysis
30
33. FIG. 6. Explicit Imperfection Model for Elastic-Plastic Analysis Recommended By ECCS
FIG. 7. Examples on Application of Notional Loads for Second-Order Elastic-Plasic Hinge
Analysis
31
35. FIG. 10. Specimen for Three-Story Frame
FIG. 11. Lateral Load-Sway Behaviour of Frame C
33
36. FIG. 12. Schematic Diagram of Test Arrangement
FIG. 13. Sway Load-Deflection Curve for Test Frame 2
34
37. FIG. 14. One-Quarter Scaled Frames.(From Wakabayashi, M. And
Matsui, C., Trans. Arch. Inst. Jpn. 193,17,1972, With Permission)
35
38. FIG. 15. Horizontal Force-Displacement Behaviours of One-Quarter Scaled
Frame.(Two Story).(From Wakabayashi, M. And Matsui, C., Trans.
Arch.Inst. Jpn. 193,17,1972, With Permission)
36
39. FIG. 16. Harrison’s Space Frame(Harrison 1964)
FIG. 17. Load-Deflection for Harrison’s Space Frame
37
40. P
P
ad
Vertical lo
P
P
Roof
2.20m
H1
tal load
Horizon 2nd floor
Z
H2
①
1.76m
Y ②
③
X 2.5 Base
m ④
3.0m
FIG. 18. Dimension and Loading Condition of Test Frame
P
P
ad
Vertical lo
P
P
Roof
2.20m
H
ta l load
Horizon 2nd floor
Z
①
1.76m
Y ②
③
X 2.5 Base
m ④
3.0m
FIG. 19. Dimensions and Loading Conditions of Test Frame in Main Test
38
41. 200
160
Horizontal load (kN)
120
80
Experiment(H1)
Analysis(H1)
Experiment(H2)
40 Analysis(H2)
0
0 10 20 30 40
Horizontal displacement (mm)
FIG. 20. Comparison of Horizontal Load-Displacement Curves for Space Test Frame 2
FIG. 21. Horizontal Load-Displacement Curve for Test Frame (Column ②)
39