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.
Size effect of plain concrete beams–an experimental studyeSAT Journals
Abstract
The paper analyses the size dependency of the fracture energy (GF) and the effective length of fracture process zone (Cf) of concrete
determined as per the Bazant’s Size effect method and RILEM Work-of-fracture methods. The fracture parameters (GF,Cf) are
determined by measuring the maximum loads of geometrically similar notched plain concrete (M25) specimens of different sizes in a
size ratio of 1:5 with different pre-cast notch depths (a/d=0.15, 0.30 and 0.45) under three point bending through load-deflection
curves. In each notch depth ratio, 15 beams are cast and tested with 03 similar specimens in each size of the beams. Total beams
tested are 45.The variation of both the fracture energy and the effective length of fracture process zone as a function of the specimen
size and notch depth is determined using Bazant’s Size effect method and RILEM Work-of-fracture method. Fracture energy and
Fracture process zone length determined by Size effect method are found to be decreasing with the increasing notch depth ratios.
Fracture energy calculated using Work-of-fracture method is increasing with the increase in size of specimen and decreasing with the
increasing notch depth ratios.
Cutting force based on modelling experiments during broaching operationPhuong Dx
1) The document presents an experimental study to determine proportionality constants for a mechanistic cutting force model during broaching operations.
2) Experiments were conducted using a shaping process to determine specific cutting energy constants for materials like mild steel, aluminum, and cast iron.
3) Measurements of cutting forces were used to calculate proportionality constants, which relate cutting forces to chip thickness area in the mechanistic model.
Experimental and numerical evaluation of plasticity model with ductile damage...IJERA Editor
This work aims to develop a methodology for numerical evaluation via finite elements applied to projects shields sheet metal. To validate the methodology physical test were conduct and were compare with the numerical simulation. In the simulation, a plasticity material modelit was used at high strain rates, besides the insertion of a damage model through forming limit diagram (FLD) to capture the initiation of damage and energy criteria for propagation of the fracture. The tested shielding design is for the II-A protection level using the type 9mm ammunition.
This document summarizes a study on plastic zone size and effective distance under mixed mode fracture using a volumetric approach. U-notched circular ring specimens made of 45CDS6 steel were subjected to compression loading with notch radii ranging from 0.15-2mm and angles from 0-33 degrees. Finite element analysis was conducted to determine stress distributions. Two methods were used to evaluate plastic zone size - the volumetric method relating it to effective stress and notch stress intensity factor, and the von Mises yield criterion. The plastic zone sizes determined from both methods showed good agreement. A new model was proposed to evaluate plastic zone size under mixed mode fracture conditions.
An Experimental Investigation into the Grindability Aspects of Newly Develope...IDES Editor
The document summarizes an experimental investigation into the grindability of a newly developed ceramic composite material called AlSiTi. The study analyzed the effects of grinding wheel speed, table feed rate, and depth of cut on grinding forces, specific energy, surface roughness, and subsurface damage using Taguchi's experimental design method. Scanning electron microscopy revealed that higher grinding forces led to greater subsurface damage. Optimizing grinding parameters and using coolants could help improve the grindability of this composite ceramic material by reducing forces and specific energy, thereby minimizing subsurface defects.
IRJET- Investigation and Analysis of Multiple Cracks in Cantilever Beam by us...IRJET Journal
The document investigates the free vibration analysis of uniform and stepped cantilever beams with single and multiple cracks using finite element modeling. An experimental study is conducted to validate the numerical results. The presence of cracks reduces the local stiffness matrix and alters the natural frequencies of the system. Results show that as crack depth increases, frequency reduction also increases for both uniform and stepped beams. Natural frequencies are more influenced by crack location than depth. Cracks near fixed ends have a greater effect on the first natural frequency mode compared to cracks near free ends.
Vibrational Analysis Of Cracked Rod Having Circumferential Crack IDES Editor
The frequency ratio of torsional vibration of a rod without crack and of rod with crack subjected to torque at the free end for various crack depth and varying crack location is investigated. It is found that even a cracked of small depth is
dangerous at the fixed end, also as the crack depth is increases more than 50% of diameter of rod there is a considerable drop in natural frequency of the rod .
Size effect of plain concrete beams–an experimental studyeSAT Journals
Abstract
The paper analyses the size dependency of the fracture energy (GF) and the effective length of fracture process zone (Cf) of concrete
determined as per the Bazant’s Size effect method and RILEM Work-of-fracture methods. The fracture parameters (GF,Cf) are
determined by measuring the maximum loads of geometrically similar notched plain concrete (M25) specimens of different sizes in a
size ratio of 1:5 with different pre-cast notch depths (a/d=0.15, 0.30 and 0.45) under three point bending through load-deflection
curves. In each notch depth ratio, 15 beams are cast and tested with 03 similar specimens in each size of the beams. Total beams
tested are 45.The variation of both the fracture energy and the effective length of fracture process zone as a function of the specimen
size and notch depth is determined using Bazant’s Size effect method and RILEM Work-of-fracture method. Fracture energy and
Fracture process zone length determined by Size effect method are found to be decreasing with the increasing notch depth ratios.
Fracture energy calculated using Work-of-fracture method is increasing with the increase in size of specimen and decreasing with the
increasing notch depth ratios.
Cutting force based on modelling experiments during broaching operationPhuong Dx
1) The document presents an experimental study to determine proportionality constants for a mechanistic cutting force model during broaching operations.
2) Experiments were conducted using a shaping process to determine specific cutting energy constants for materials like mild steel, aluminum, and cast iron.
3) Measurements of cutting forces were used to calculate proportionality constants, which relate cutting forces to chip thickness area in the mechanistic model.
Experimental and numerical evaluation of plasticity model with ductile damage...IJERA Editor
This work aims to develop a methodology for numerical evaluation via finite elements applied to projects shields sheet metal. To validate the methodology physical test were conduct and were compare with the numerical simulation. In the simulation, a plasticity material modelit was used at high strain rates, besides the insertion of a damage model through forming limit diagram (FLD) to capture the initiation of damage and energy criteria for propagation of the fracture. The tested shielding design is for the II-A protection level using the type 9mm ammunition.
This document summarizes a study on plastic zone size and effective distance under mixed mode fracture using a volumetric approach. U-notched circular ring specimens made of 45CDS6 steel were subjected to compression loading with notch radii ranging from 0.15-2mm and angles from 0-33 degrees. Finite element analysis was conducted to determine stress distributions. Two methods were used to evaluate plastic zone size - the volumetric method relating it to effective stress and notch stress intensity factor, and the von Mises yield criterion. The plastic zone sizes determined from both methods showed good agreement. A new model was proposed to evaluate plastic zone size under mixed mode fracture conditions.
An Experimental Investigation into the Grindability Aspects of Newly Develope...IDES Editor
The document summarizes an experimental investigation into the grindability of a newly developed ceramic composite material called AlSiTi. The study analyzed the effects of grinding wheel speed, table feed rate, and depth of cut on grinding forces, specific energy, surface roughness, and subsurface damage using Taguchi's experimental design method. Scanning electron microscopy revealed that higher grinding forces led to greater subsurface damage. Optimizing grinding parameters and using coolants could help improve the grindability of this composite ceramic material by reducing forces and specific energy, thereby minimizing subsurface defects.
IRJET- Investigation and Analysis of Multiple Cracks in Cantilever Beam by us...IRJET Journal
The document investigates the free vibration analysis of uniform and stepped cantilever beams with single and multiple cracks using finite element modeling. An experimental study is conducted to validate the numerical results. The presence of cracks reduces the local stiffness matrix and alters the natural frequencies of the system. Results show that as crack depth increases, frequency reduction also increases for both uniform and stepped beams. Natural frequencies are more influenced by crack location than depth. Cracks near fixed ends have a greater effect on the first natural frequency mode compared to cracks near free ends.
Vibrational Analysis Of Cracked Rod Having Circumferential Crack IDES Editor
The frequency ratio of torsional vibration of a rod without crack and of rod with crack subjected to torque at the free end for various crack depth and varying crack location is investigated. It is found that even a cracked of small depth is
dangerous at the fixed end, also as the crack depth is increases more than 50% of diameter of rod there is a considerable drop in natural frequency of the rod .
Modified maximum tangential stress criterion for fracture behavior of zirconi...dentalid
The veneering porcelain sintered on zirconia is widely used in dental prostheses, but
repeated mechanical loadings may cause a fracture such as edge chipping or delamination.
In order to predict the crack initiation angle and fracture toughness of zirconia/veneer bilayered
components subjected to mixed mode loadings, the accuracy of a new and
traditional fracture criteria are investigated. A modified maximum tangential stress
criterion considering the effect of T-stress and critical distance theory is introduced, and
compared to three traditional fracture criteria. Comparisons to the recently published
fracture test data show that the traditional fracture criteria are not able to properly predict
the fracture initiation conditions in zirconia/veneer bi-material joints. The modified
maximum tangential stress criterion provides more accurate predictions of the experimental
results than the traditional fracture criteria
Finite Element Analysis of Damping Performance of VEM Materials Using CLD Tec...IJERA Editor
Most engineering structures experiences vibrational motion, this unwanted vibrations can result in premature
structural failure. Many methods are developed which enhances capability of damping such as constrained layer
damping. Shear motion is produced in VEM due to constraining layer to resist unwanted vibrational energy.
This paper shows theeffect of varying the thickness of viscoelastic materials on damping performance of CLD
beam.The damping performance is measured in terms of modal loss factor.
This document summarizes a study that used finite element analysis to analyze stress concentrations at bolt hole locations in lap joints. A 3D finite element model of a lap joint was developed using Abaqus software. Non-linear analysis considered the stress-strain behavior of materials and interactions between bolt and plate surfaces. Parametric studies varied the end distance and compared results to failure criteria in design codes. Stress patterns were compared to bearing capacity equations to determine the optimum end distance that prevents premature failure.
Can fracture mechanics predict damage due disaster of structureseSAT Publishing House
This document discusses how fracture mechanics can be used to better predict damage and failure of structures. It notes that current design codes are based on small-scale laboratory tests and do not account for size effects, which can lead to more brittle failures in larger structures. The document outlines how fracture mechanics considers factors like size effect, ductility, and minimum reinforcement that influence the strength and failure behavior of structures. It provides examples of how fracture mechanics has been applied to problems like evaluating shear strength in deep beams and investigating a failure of an oil platform structure. The document argues that fracture mechanics provides a more scientific basis for structural design compared to existing empirical code provisions.
This document discusses the influence of notch parameters on the fracture behavior of notched components. It summarizes a study that used finite element analysis to analyze the stress intensity factor and stress field near the root of elliptical notches in CT specimens made of steel, under uniaxial tensile loading. The study compared results from the volumetric method and Irwin models for determining effective distance, effective stress, and relative gradient stress, which are key factors in the volumetric method. Results showed that increasing the size of the minor notch axis reduces elastic-plastic stresses and effective stresses. The Irwin model was relatively unaffected by changes in notch length.
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.
Prediction Models for Sliding Wear of AA3003/Al2O3 CompositesIJERA Editor
In the present work, the AA3003/Al2O3 metal matrix composites were manufactured at 10% and 30% volume
fractions of Al2O3. The composites were wear tested at different levels of normal load, sliding speed and sliding
distances. The microstructure of worn surfaces pertaining to AA3003/ Al2O3 composite reveals the fracture of
AA3033 alloy matrix as well as the detachment of Al2O3 particles from the matrix.
This document summarizes research on the tensile and flexural behavior of ultra-high performance concrete (UHPC) under high-speed and impact loads. High-speed testing systems were used to apply tensile and flexural impact loads to UHPC specimens. Digital image correlation was utilized to analyze crack propagation and strain fields. The research found that UHPC achieved tensile strengths over 20 MPa and flexural strengths exceeding 25 MPa. An analytical model was also developed that could predict UHPC's flexural impact response based on parameters like residual strength, localization zone size, and tensile and flexural properties.
TRANSIENT ANALYSIS OF PIEZOLAMINATED COMPOSITE PLATES USING HSDTP singh
Piezoelectric materials have excellent sensing and actuating capabilities have made them the most practical smart materials to integrate with laminated structures. Integrated structure system can be called a smart structure because of its ability to perform self-diagnosis and quick adaption to environment changes. An analytical procedure has been developed in the work based on higher order shear deformation theory subjected to electromechanical loading for investigating transient characteristics of smart material plates. For analysis two displacement models are to be considered i.e., model-1 accounts for strain in thickness direction is zero whereas in model-2 in-plane displacements are expanded as cubic functions of the thickness coordinate. Navier’s technique has been adopted for obtaining solutions of anti-symmetric cross–ply and angle-ply laminates of both model-1 and model-2 with simply supported boundary conditions. For obtaining transient response of a laminated composite plate attached with piezoelectric layer Newmark’s method has been used. Effect of thickness coordinate of composite laminated plates attached with piezoelectric layer subjected to electromechanical loadings is studied.
D.H. Gordon et al., Polymer, 35, (1994) 2554 - 2559.Duncan Gordon
This document summarizes a study on the drawing of poly(ethylene terephthalate) (PET) films. The key findings are:
1) Uniaxially drawn PET films were redrawn, and measurements showed the stress-strain behavior could be described by a single molecular network model, regardless of the drawing process.
2) Refractive index, density, and shrinkage stress measurements of uniaxially and biaxially drawn films depended only on the total draw ratio, supporting the idea of a preserved molecular network.
3) The drawing stress showed maximum strain rate dependence at the glass transition temperature of 80°C, with little effect at higher or lower temperatures.
Numerical modeling of the welding defect influence on fatigue life of the wel...inventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
This document discusses flexural design procedures for UHPC beams and slabs. It presents a simplified bilinear moment-curvature relationship for UHPC and derives closed-form solutions for the load-deflection response of simply supported UHPC beams and panels. Equilibrium-based equations are used to determine the moment and curvature distributions along the beam. Parametric studies examine the effects of varying normalized moment and curvature on the curvature distribution and 2D deflection contour. Experimental verification is discussed.
Analysis of stiffened isotropic and composite plateIRJET Journal
This document summarizes a research paper that analyzed both isotropic and composite plates with and without stiffeners using finite element modeling. It presented the following key points:
1. Finite element models of isotropic and composite plates were created using shell and solid elements in ANSYS to analyze the effect of stiffeners on plate deformation and stress.
2. Parametric studies were performed by varying the length, thickness, and height of stiffeners to minimize plate deformation without increasing material volume.
3. Results showed that stiffened plates had significantly less deformation than bare plates for the same material volume. Deformation generally decreased with increasing stiffener size.
The document describes a study that uses probabilistic modeling and finite element analysis to develop a robust design for an automotive battery tray that accounts for manufacturing variations. Random variables for material properties, thickness, and loading are defined probabilistically. Monte Carlo and response surface sampling are used to determine the probabilistic response distributions for stress and strain. The mean and standard deviation of the response distributions are calculated and used to size the component based on six sigma design criteria, with the goal of minimizing weight while maintaining structural integrity compared to a traditional nominal design approach.
Grain size dependence of fracture toughness and crack-growth resistanceAslan Ahadi
1) The fracture toughness (KIC) and crack growth resistance (KR) of superelastic NiTi decrease with reductions in grain size from the micrometer to nanometer scale.
2) In-situ digital image correlation and infrared thermography during crack opening tests show that the size of the crack-tip phase transformation zone and maximum force also decrease with smaller grain sizes.
3) Both intrinsic and extrinsic toughening mechanisms are influenced by grain size, as nanocrystalline NiTi exhibits less ductility and constrained phase transformation compared to larger grain sizes.
Numerical Analysis of Engineered Steel Fibers as Shear Reinforcement in RC BeamsP singh
Using suitable fibers and additives in concrete to enhance its performance is an important consideration in the concrete industry with regard to the structural aspects of concrete. The purpose of this project is to investigate numerically the effectiveness of the engineered steel fiber as shear reinforcement in RC beams. Here steel fibers completely replaces the shear reinforcement (stirrups & links). The dimension of beam taken was 1000*150*150 mm with aspect ratio 80. The beams were reinforced with 10 mm steel bars as secondary reinforcement and 12 mm bars as main reinforcement on the tension side. Numerical analysis using ANSYS R16.1 software package was carried out. The load-deflection curves for the beams with different dosage of fibers were drawn superimposing their numerical values. Initially, in all three cases the curve was linear elastic and about 80% of ultimate load they tend to be non-linear. It was observed that there was fair agreement between the results which indicates some favourable aspects concerning the use of steel fibres as shear reinforcement in concrete beams. It was investigated that the inclusion of steel fibres (Hook End Type) improves the shear strength of RC beams without stirrups by improving the matrix between concrete and steel fibers. Thus this project focuses in the design and analysis using the software ANSYS R16.1 for an alternative steel reinforcement with better or equivalent performance.
IRJET - Analysis and Model for Flexural Behaviour of Confined Rectangular...IRJET Journal
This document summarizes an analysis of the flexural behavior of confined and unconfined rectangular concrete beams. Three beam samples were tested: one with internal confinement using stirrups, one with external confinement using mesh wrapping, and one without confinement. Testing found that the externally confined beam had the highest load carrying capacity and withstood the greatest strains before failure. The internally confined beam performed better than the unconfined beam but not as well as the externally confined beam. In conclusion, external confinement was found to be the most effective at improving a beam's ductility and strength.
Hyperelastic material models in finite element analysis of polymersKartik Srinivas
This paper describes the Hyperelastic material models and strain energy functions used in the finite element analysis (FEA) of polymers. Material characterization testing
A review on different destructive methods to determine the compressive streng...IJERD Editor
Determination of the compressive strength of an existing masonry attracted the attention of many scientists and researchers around the world. Most of these researchers, scientists and engineers want to find the best way to obtain the compressive strength of masonry in situ with high accuracy, and less cost. There are many methods to determine the compressive strength of masonry. Some of these methods are destructive methods and others are non-destructive methods and others are partially destructive. Each one of these testing methods has advantages and disadvantages .this paper presents different destructive testing Methodsfor obtaining the compressive strength of an existing masonry. Testing procedure, the main advantages and the problems of each method are explored.
Security constrained optimal load dispatch using hpso technique for thermal s...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 document summarizes a study that assessed indoor air quality in various workplaces in an automobile industry. Air samples were collected from five sites (fuel tank cell, shot blasting, liquid painting, PT-CED, dynamometer testing) using a high volume sampler to measure concentrations of total aerosol mass, respirable aerosol mass, sulfur dioxide, nitrogen dioxide, and carbon monoxide. The results showed that some sites exceeded occupational safety and health administration (OSHA) limits for certain pollutants. Specifically, the liquid painting, shot blasting, dynamometer testing, and fuel tank cell areas exceeded limits for total aerosol mass and respirable aerosol mass. The shot blasting,
Modified maximum tangential stress criterion for fracture behavior of zirconi...dentalid
The veneering porcelain sintered on zirconia is widely used in dental prostheses, but
repeated mechanical loadings may cause a fracture such as edge chipping or delamination.
In order to predict the crack initiation angle and fracture toughness of zirconia/veneer bilayered
components subjected to mixed mode loadings, the accuracy of a new and
traditional fracture criteria are investigated. A modified maximum tangential stress
criterion considering the effect of T-stress and critical distance theory is introduced, and
compared to three traditional fracture criteria. Comparisons to the recently published
fracture test data show that the traditional fracture criteria are not able to properly predict
the fracture initiation conditions in zirconia/veneer bi-material joints. The modified
maximum tangential stress criterion provides more accurate predictions of the experimental
results than the traditional fracture criteria
Finite Element Analysis of Damping Performance of VEM Materials Using CLD Tec...IJERA Editor
Most engineering structures experiences vibrational motion, this unwanted vibrations can result in premature
structural failure. Many methods are developed which enhances capability of damping such as constrained layer
damping. Shear motion is produced in VEM due to constraining layer to resist unwanted vibrational energy.
This paper shows theeffect of varying the thickness of viscoelastic materials on damping performance of CLD
beam.The damping performance is measured in terms of modal loss factor.
This document summarizes a study that used finite element analysis to analyze stress concentrations at bolt hole locations in lap joints. A 3D finite element model of a lap joint was developed using Abaqus software. Non-linear analysis considered the stress-strain behavior of materials and interactions between bolt and plate surfaces. Parametric studies varied the end distance and compared results to failure criteria in design codes. Stress patterns were compared to bearing capacity equations to determine the optimum end distance that prevents premature failure.
Can fracture mechanics predict damage due disaster of structureseSAT Publishing House
This document discusses how fracture mechanics can be used to better predict damage and failure of structures. It notes that current design codes are based on small-scale laboratory tests and do not account for size effects, which can lead to more brittle failures in larger structures. The document outlines how fracture mechanics considers factors like size effect, ductility, and minimum reinforcement that influence the strength and failure behavior of structures. It provides examples of how fracture mechanics has been applied to problems like evaluating shear strength in deep beams and investigating a failure of an oil platform structure. The document argues that fracture mechanics provides a more scientific basis for structural design compared to existing empirical code provisions.
This document discusses the influence of notch parameters on the fracture behavior of notched components. It summarizes a study that used finite element analysis to analyze the stress intensity factor and stress field near the root of elliptical notches in CT specimens made of steel, under uniaxial tensile loading. The study compared results from the volumetric method and Irwin models for determining effective distance, effective stress, and relative gradient stress, which are key factors in the volumetric method. Results showed that increasing the size of the minor notch axis reduces elastic-plastic stresses and effective stresses. The Irwin model was relatively unaffected by changes in notch length.
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.
Prediction Models for Sliding Wear of AA3003/Al2O3 CompositesIJERA Editor
In the present work, the AA3003/Al2O3 metal matrix composites were manufactured at 10% and 30% volume
fractions of Al2O3. The composites were wear tested at different levels of normal load, sliding speed and sliding
distances. The microstructure of worn surfaces pertaining to AA3003/ Al2O3 composite reveals the fracture of
AA3033 alloy matrix as well as the detachment of Al2O3 particles from the matrix.
This document summarizes research on the tensile and flexural behavior of ultra-high performance concrete (UHPC) under high-speed and impact loads. High-speed testing systems were used to apply tensile and flexural impact loads to UHPC specimens. Digital image correlation was utilized to analyze crack propagation and strain fields. The research found that UHPC achieved tensile strengths over 20 MPa and flexural strengths exceeding 25 MPa. An analytical model was also developed that could predict UHPC's flexural impact response based on parameters like residual strength, localization zone size, and tensile and flexural properties.
TRANSIENT ANALYSIS OF PIEZOLAMINATED COMPOSITE PLATES USING HSDTP singh
Piezoelectric materials have excellent sensing and actuating capabilities have made them the most practical smart materials to integrate with laminated structures. Integrated structure system can be called a smart structure because of its ability to perform self-diagnosis and quick adaption to environment changes. An analytical procedure has been developed in the work based on higher order shear deformation theory subjected to electromechanical loading for investigating transient characteristics of smart material plates. For analysis two displacement models are to be considered i.e., model-1 accounts for strain in thickness direction is zero whereas in model-2 in-plane displacements are expanded as cubic functions of the thickness coordinate. Navier’s technique has been adopted for obtaining solutions of anti-symmetric cross–ply and angle-ply laminates of both model-1 and model-2 with simply supported boundary conditions. For obtaining transient response of a laminated composite plate attached with piezoelectric layer Newmark’s method has been used. Effect of thickness coordinate of composite laminated plates attached with piezoelectric layer subjected to electromechanical loadings is studied.
D.H. Gordon et al., Polymer, 35, (1994) 2554 - 2559.Duncan Gordon
This document summarizes a study on the drawing of poly(ethylene terephthalate) (PET) films. The key findings are:
1) Uniaxially drawn PET films were redrawn, and measurements showed the stress-strain behavior could be described by a single molecular network model, regardless of the drawing process.
2) Refractive index, density, and shrinkage stress measurements of uniaxially and biaxially drawn films depended only on the total draw ratio, supporting the idea of a preserved molecular network.
3) The drawing stress showed maximum strain rate dependence at the glass transition temperature of 80°C, with little effect at higher or lower temperatures.
Numerical modeling of the welding defect influence on fatigue life of the wel...inventy
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
This document discusses flexural design procedures for UHPC beams and slabs. It presents a simplified bilinear moment-curvature relationship for UHPC and derives closed-form solutions for the load-deflection response of simply supported UHPC beams and panels. Equilibrium-based equations are used to determine the moment and curvature distributions along the beam. Parametric studies examine the effects of varying normalized moment and curvature on the curvature distribution and 2D deflection contour. Experimental verification is discussed.
Analysis of stiffened isotropic and composite plateIRJET Journal
This document summarizes a research paper that analyzed both isotropic and composite plates with and without stiffeners using finite element modeling. It presented the following key points:
1. Finite element models of isotropic and composite plates were created using shell and solid elements in ANSYS to analyze the effect of stiffeners on plate deformation and stress.
2. Parametric studies were performed by varying the length, thickness, and height of stiffeners to minimize plate deformation without increasing material volume.
3. Results showed that stiffened plates had significantly less deformation than bare plates for the same material volume. Deformation generally decreased with increasing stiffener size.
The document describes a study that uses probabilistic modeling and finite element analysis to develop a robust design for an automotive battery tray that accounts for manufacturing variations. Random variables for material properties, thickness, and loading are defined probabilistically. Monte Carlo and response surface sampling are used to determine the probabilistic response distributions for stress and strain. The mean and standard deviation of the response distributions are calculated and used to size the component based on six sigma design criteria, with the goal of minimizing weight while maintaining structural integrity compared to a traditional nominal design approach.
Grain size dependence of fracture toughness and crack-growth resistanceAslan Ahadi
1) The fracture toughness (KIC) and crack growth resistance (KR) of superelastic NiTi decrease with reductions in grain size from the micrometer to nanometer scale.
2) In-situ digital image correlation and infrared thermography during crack opening tests show that the size of the crack-tip phase transformation zone and maximum force also decrease with smaller grain sizes.
3) Both intrinsic and extrinsic toughening mechanisms are influenced by grain size, as nanocrystalline NiTi exhibits less ductility and constrained phase transformation compared to larger grain sizes.
Numerical Analysis of Engineered Steel Fibers as Shear Reinforcement in RC BeamsP singh
Using suitable fibers and additives in concrete to enhance its performance is an important consideration in the concrete industry with regard to the structural aspects of concrete. The purpose of this project is to investigate numerically the effectiveness of the engineered steel fiber as shear reinforcement in RC beams. Here steel fibers completely replaces the shear reinforcement (stirrups & links). The dimension of beam taken was 1000*150*150 mm with aspect ratio 80. The beams were reinforced with 10 mm steel bars as secondary reinforcement and 12 mm bars as main reinforcement on the tension side. Numerical analysis using ANSYS R16.1 software package was carried out. The load-deflection curves for the beams with different dosage of fibers were drawn superimposing their numerical values. Initially, in all three cases the curve was linear elastic and about 80% of ultimate load they tend to be non-linear. It was observed that there was fair agreement between the results which indicates some favourable aspects concerning the use of steel fibres as shear reinforcement in concrete beams. It was investigated that the inclusion of steel fibres (Hook End Type) improves the shear strength of RC beams without stirrups by improving the matrix between concrete and steel fibers. Thus this project focuses in the design and analysis using the software ANSYS R16.1 for an alternative steel reinforcement with better or equivalent performance.
IRJET - Analysis and Model for Flexural Behaviour of Confined Rectangular...IRJET Journal
This document summarizes an analysis of the flexural behavior of confined and unconfined rectangular concrete beams. Three beam samples were tested: one with internal confinement using stirrups, one with external confinement using mesh wrapping, and one without confinement. Testing found that the externally confined beam had the highest load carrying capacity and withstood the greatest strains before failure. The internally confined beam performed better than the unconfined beam but not as well as the externally confined beam. In conclusion, external confinement was found to be the most effective at improving a beam's ductility and strength.
Hyperelastic material models in finite element analysis of polymersKartik Srinivas
This paper describes the Hyperelastic material models and strain energy functions used in the finite element analysis (FEA) of polymers. Material characterization testing
A review on different destructive methods to determine the compressive streng...IJERD Editor
Determination of the compressive strength of an existing masonry attracted the attention of many scientists and researchers around the world. Most of these researchers, scientists and engineers want to find the best way to obtain the compressive strength of masonry in situ with high accuracy, and less cost. There are many methods to determine the compressive strength of masonry. Some of these methods are destructive methods and others are non-destructive methods and others are partially destructive. Each one of these testing methods has advantages and disadvantages .this paper presents different destructive testing Methodsfor obtaining the compressive strength of an existing masonry. Testing procedure, the main advantages and the problems of each method are explored.
Security constrained optimal load dispatch using hpso technique for thermal s...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 document summarizes a study that assessed indoor air quality in various workplaces in an automobile industry. Air samples were collected from five sites (fuel tank cell, shot blasting, liquid painting, PT-CED, dynamometer testing) using a high volume sampler to measure concentrations of total aerosol mass, respirable aerosol mass, sulfur dioxide, nitrogen dioxide, and carbon monoxide. The results showed that some sites exceeded occupational safety and health administration (OSHA) limits for certain pollutants. Specifically, the liquid painting, shot blasting, dynamometer testing, and fuel tank cell areas exceeded limits for total aerosol mass and respirable aerosol mass. The shot blasting,
The document describes a system to monitor and control liquid flow in pipelines using a Raspberry Pi, Arduino, and other hardware components. A Hall effect sensor measures the liquid flow rate, which is read by an Arduino and sent to a Raspberry Pi. The Raspberry Pi controls an electro-valve connected to the pipeline and hosts a web server to monitor and control the flow remotely over the Internet. The system was tested successfully with a water pipeline setup and allows remote monitoring and control of liquid flows in industrial processes.
Key frame extraction for video summarization using motion activity descriptorseSAT 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
Detect and overcome the selfish problem in wifi network using energy sharingeSAT 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
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.
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.
Heat transfer augmentation in different geometries of dimpled surface under n...eSAT Publishing House
The document experimentally studies heat transfer augmentation through various dimpled surface geometries under natural convection. It tests aluminum and copper plates with square, circular, and triangular dimple shapes. It finds that heat transfer rate, coefficient, and Nusselt number all increase for dimpled surfaces compared to plain surfaces, and are highest for triangular dimples with the apex facing inlet air flow. Heat transfer generally increases more for aluminum with square and triangular base dimples, while copper performs better with circular and triangular apex dimples. The study concludes dimples enhance heat transfer under natural convection compared to plain surfaces.
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
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.
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.
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.
Parametric study of response of an asymmetric building for various earthquake...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
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.
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 document discusses partial encryption of compressed video. It proposes a method where only crucial parts of compressed video are encrypted, rather than encrypting the entire video stream. This results in significant reductions in processing time, computational requirements, bit rate, and bandwidth needed for encryption and transmission. The document provides background on video compression standards like MPEG-4 and encryption techniques. It then describes testing of the partial encryption method on images and outlines the problems with fully encrypting video streams that partial encryption aims to address.
This document summarizes several papers on document clustering techniques. It discusses hierarchical clustering and similarity measures, as well as multi-representation clustering. Several clustering algorithms are examined, including K-means clustering and graph-based clustering. The document also analyzes similarity measures like multi-viewpoint similarity and evaluates the performance of different clustering methods on document collections.
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.
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
Response sensitivity of the structure using vibration based damage detection ...eSAT Journals
Abstract
Many developments have been carried out in order to try to quantify the effects produced by damage and the vibration based methods
of damage diagnostics are proved to be promising. In the present study, a two storey one bay steel portal frame with cross bracing is
considered as an undamaged case. The damage is introduced to the frame by removing the bracing at various levels. The modal
parameters of the undamaged and damaged frames were extracted by using FEM software ANSYS 14.5 and validated through
experimental results performed using mini shake table. The Frequency response function (FRF) plot is drawn from the experimental
results. Further the damage is introduced to the frame by reducing the young’s modulus, reducing the cross sectional area and
increasing the temperature due to fire in bracing and at each floor is also studied by using ANSYS 14.5 by performing the modal
analysis. The results show that the natural frequencies for the damaged structure decreases and the amplitude increases.
Keywords: steel frame structure, damage detection, sensitivity analysis, Dynamic response, fire temperature.
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
Seismic analysis of high damping rubber bearings for base isolationeSAT Journals
This document analyzes the seismic behavior of high damping rubber bearings used for base isolation of structures. It describes modeling a rubber bearing in ANSYS and performing a transient analysis using the displacement time history from the 1940 El Centro earthquake. The analysis found that the bearing could withstand displacements up to 350% of the rubber layer thickness without cavitation occurring in the rubber. Stresses induced in the bearing remained below permissible limits, indicating it could effectively isolate structures from ground motions up to 0.3g accelerations.
In the material testing laboratory, Tensile test was done on a mild steel specimen as figure 4 to identify the young’s modulus, ultimate tensile strength, yield strength and percentage elongation. The results were as table 1
Computational analysis of effect of stacking orientation on low velocity impa...eSAT Publishing House
This document summarizes a study on the effect of stacking orientation on the low velocity impact behavior of glass fiber reinforced plastic (GFRP) composite laminates using finite element analysis. The study used ABAQUS to model GFRP laminates with different stacking orientations impacted by a rigid sphere. Results showed that maximum contact force increased with increasing difference between orientation angles at equal impact energy. Orientations with higher bending stiffness like [00/750/-750/900]s had higher maximum contact forces. The model can be extended to predict failure modes like delamination using damage criteria.
IRJET- Cantilever Beam Crack Detection using FEA and FFT AnalyserIRJET Journal
This document presents a method to detect cracks in cantilever beams using finite element analysis and natural frequency measurements. A cracked beam is modeled as two segments connected by a spring. Natural frequencies are obtained through FEA for uncracked and cracked beams. Equations relate the stiffness of the spring and crack location to changes in natural frequency. Plots of stiffness versus crack location from three modes intersect at the actual location. The method accurately predicts crack size and position to within 4% error. A case study applies the method to a cantilever beam, generating mode shapes through FEA and using equations to determine crack parameters from frequency data.
Abstract The present research work is to determine buckling load per unit length in rectangular plate with circular cut-outs under bi-axial compression using 2D finite element analysis. The commercial finite element analysis software ANSYS has been successfully executed. The buckling factors are evaluated by changing the position of the holes, length to thickness ratio. The effect of changing the position of holes, a/b ratio, b/t ratio and buckling load per unit length is discussed. The results shows that buckling load per unit length is in clamped-clamped boundary conditions and buckling load is more at top positioned hole, decreases with increase in aspect ratio, decrease with increase breadth to thickness ratio. Keywords: Buckling analysis, Finite element method, Buckling load per unit length , carbon/epoxy composite plate, aspect ratio, b/t ratio, and Biaxial load.
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 document discusses a study on the effect of liquid additives on the strength and behavior of reinforced concrete model beams. Six model beams were tested with different proportions of high-range water reducing admixtures by weight of cement ranging from 0% to 2%. Compressive strength, modulus of elasticity, shear modulus, modulus of volume change, Poisson's ratio, deflection, and cracking were measured and calculated at 28 days. The best results were achieved using an admixture ratio of 1.6%, which improved compressive strength and modulus of elasticity but had no effect on cracking behavior. Control cube specimens were also tested to determine compressive strength at 7 and 28 days. The experimental results are presented in tables.
Comparison of the lateral deflection at midpoint of long & short side columnIAEME Publication
This document summarizes a study that used finite element analysis to compare the lateral deflection of long and short side reinforced concrete columns subjected to blast loading. The analysis used ANSYS to model 8 columns with different transverse and longitudinal reinforcement. It found that the long side columns experienced significantly higher maximum lateral deformations than the short side columns. Ratios of short to long side column deformation ranged from 0.24 to 0.38 depending on the column. The study concluded that column length and orientation affects deformation under blast loading, with long side columns experiencing greater impacts.
The impact of the diameter to height ratio on the compressibility parameters ...eSAT Journals
Abstract Compressibility parameters of fine-grained soils are mainly influenced by soil mineralogy, moisture content and soil diameter to height ratio (D/H). The British and American standards suggested that to obtain accurate engineering properties; it is necessary to use D/H ratio of 4 and 2.5 respectively to eliminate friction between the soil and the structure. In the current study, various D/H ratios were adopted ranging from 0.5 to 11. The D/H ratios effect on some compressibility parameters such as coefficient of consolidation (cv), compression index (cc) and coefficient of volume compressibility (mv) were analysed. Additionally, the impact of the D/H ratio on the acquire cv values were also presented where three methods were used namely: Casagrande, Taylor and Inflection method. The scaling effects based on cv ratio [cv (√t) / cv (log t)] from Oedometer tests using different D/H ratios are also presented. The results showed that Taylor’s method is the most appropriate way to achieve an accurate cv and an increase in pressure leads to a reduction in cc and a gradual decrease in mv. The validation of the experimental results on a finite element software package PLAXIS was completed. Keywords: Compressibility, D/H ratio, Fine-grained soil, Friction
Study of behaviour of composite beams with truss type shear connectoreSAT Journals
This document summarizes a study that used finite element analysis to optimize the design of truss-type shear connectors used in composite beams. Various parameters of the shear connectors were analyzed, including angle of inclination, bar diameter, and depth of embedment. Angles between 60-75 degrees were found to be most efficient, with minimal changes when bar diameters were varied. The ultimate load capacity was found to be independent of depth of embedment. Additional models analyzed the influence of cohesion and friction at the interface, finding that cohesion up to 2 MPa resulted in behavior similar to a solid beam.
Deflection control in rcc beams by using mild steel strips (an experimental i...eSAT Publishing House
1) The document discusses an experimental investigation into using mild steel strips as a composite material with traditional reinforced concrete beams to help control deflection.
2) Three types of beams were tested - a control RCC beam, and two beams with mild steel strips embedded vertically along the sides in different configurations to increase stiffness.
3) Preliminary results found that deflection was reduced by about 30% and strength increased by about 25% in the composite beams compared to the control beam.
Investigations on material casualty of plates under impact load conditionseSAT Journals
This document summarizes an investigation into the material damage of plates under impact load conditions. Finite element models of tungsten fragments impacting mild steel and titanium plates were created in LS-DYNA. The kinetic energy, velocity, von mises stress, effective plastic strain, and hole diameter damage of the plates were measured for impact velocities of 300, 500, 700, and 1000 mm/ms. Higher impact velocities led to greater decreases in fragment velocity and kinetic energy upon impact, indicating more energy was absorbed by the plates. Von mises stresses and plastic strains in the plates and fragment increased only slightly with higher velocities. Greater impact velocities produced larger holes in the plates, showing higher damage.
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.
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.
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.
Comparative Study of Ferrocement Panels Under Blast Loading by Finite Element...IRJET Journal
This document analyzes the behavior of ferrocement panels under blast loading using finite element analysis in ANSYS. Ferrocement panels with 2-layer and 3-layer mesh configurations and thicknesses of 18mm and 25mm were modeled and subjected to blast loads at varying standoff distances. The results found that panels with greater thickness and mesh layers experienced less deformation and stress under blast loads. Specifically, the 25mm thick 3-layer panel showed 46% less deformation and 58% less strain compared to the 18mm thick 2-layer panel. Therefore, thicker ferrocement panels with more mesh layers provide better blast resistance and should be used for structures at high risk of explosions.
Analytical study of abutment and pile behaviour of iab with soil interactioneSAT 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
Surface quality enrichment using fine particle impact damper in boring operat...eSAT Journals
Abstract Boring operations are challenging owing to limited process performance due to inherent tool overhang and resulting vibrations. The tool vibrations can be suppressed with insertion of suitable damping methodology. The fine particle impact damping offers a better damping method. Due to its conceptual simplicity, potential effectiveness over a wide frequency range, temperature and degradation insensitivity and cost-effectiveness, particle damping is an attractive passive damping. The fine particles embedded within small hole in a vibrating structure to dissipate the exciting energy thereby damping the vibrations. The present work, investigates the improvement of surface quality of boring operation using fine particle impact damper. Substantial improvement of surface quality of the internally machined surfaces has been noticed in the experiments. Keywords: Boring tool, Impact damping, Surface quality, Tool overhang, vibration control.
Similar to Size effect of plain concrete beams–an experimental (20)
Hudhud cyclone caused extensive damage in Visakhapatnam, India in October 2014, especially to tree cover. This will likely impact the local environment in several ways: increased air pollution as trees absorb less; higher temperatures without tree canopy; increased erosion and landslides. It also created large amounts of waste from destroyed trees. Proper management of solid waste is needed to prevent disease spread. Suggested measures include restoring damaged plants, building fountains to reduce heat, mandating light-colored buildings, improving waste management, and educating public on health risks. Overall, changes are needed to water, land, and waste practices to rebuild the environment after the cyclone removed green cover.
Impact of flood disaster in a drought prone area – case study of alampur vill...eSAT Publishing House
1) In September-October 2009, unprecedented heavy rainfall and dam releases caused widespread flooding in Alampur village in Mahabub Nagar district, a historically drought-prone area.
2) The flood damaged or destroyed homes, buildings, infrastructure, crops, and documents. It displaced many residents and cut off the village.
3) The socioeconomic conditions and mud-based construction of homes in the village exacerbated the flood's impacts, making damage more severe and recovery more difficult.
The document summarizes the Hudhud cyclone that struck Visakhapatnam, India in October 2014. It describes the cyclone's formation, rapid intensification to winds of 175 km/h, and landfall near Visakhapatnam. The cyclone caused extensive damage estimated at over $1 billion and at least 109 deaths in India and Nepal. Infrastructure like buildings, bridges, and power lines were destroyed. Crops and fishing boats were also damaged. The document then discusses coping strategies and improvements needed to disaster management plans to better prepare for future cyclones.
Groundwater investigation using geophysical methods a case study of pydibhim...eSAT Publishing House
This document summarizes the results of a geophysical investigation using vertical electrical sounding (VES) methods at 13 locations around an industrial area in India. The VES data was interpreted to generate geo-electric sections and pseudo-sections showing subsurface resistivity variations. Three main layers were typically identified - a high resistivity topsoil, a weathered middle layer, and a basement rock. Pseudo-sections revealed relatively more weathered areas in the northwest and southwest. Resistivity sections helped identify zones of possible high groundwater potential based on low resistivity anomalies sandwiched between more resistive layers. The study concluded the electrical resistivity method was useful for understanding subsurface geology and identifying areas prospective for groundwater exploration.
Flood related disasters concerned to urban flooding in bangalore, indiaeSAT Publishing House
1. The document discusses urban flooding in Bangalore, India. It describes how factors like heavy rainfall, population growth, and improper land use have contributed to increased flooding in the city.
2. Flooding events in 2013 are analyzed in detail. A November rainfall caused runoff six times higher than the drainage capacity, inundating low-lying residential areas.
3. Impacts of urban flooding include disrupted daily life, damaged infrastructure, and decreased economic activity in affected areas. The document calls for improved flood management strategies to better mitigate urban flooding risks in Bangalore.
Enhancing post disaster recovery by optimal infrastructure capacity buildingeSAT Publishing House
This document discusses enhancing post-disaster recovery through optimal infrastructure capacity building. It presents a model to minimize the cost of meeting demand using auxiliary capacities when disaster damages infrastructure. The model uses genetic algorithms to select optimal capacity combinations. The document reviews how infrastructure provides vital services supporting recovery activities and discusses classifying infrastructure into six types. When disaster reduces infrastructure services, a gap forms between community demands and available support, hindering recovery. The proposed research aims to identify this gap and optimize capacity selection to fill it cost-effectively.
Effect of lintel and lintel band on the global performance of reinforced conc...eSAT Publishing House
This document analyzes the effect of lintels and lintel bands on the seismic performance of reinforced concrete masonry infilled frames through non-linear static pushover analysis. Four frame models are considered: a frame with a full masonry infill wall; a frame with a central opening but no lintel/band; a frame with a lintel above the opening; and a frame with a lintel band above the opening. The results show that the full infill wall model has 27% higher stiffness and 32% higher strength than the model with just an opening. Models with lintels or lintel bands have slightly higher strength and stiffness than the model with just an opening. The document concludes lintels and lintel
Wind damage to trees in the gitam university campus at visakhapatnam by cyclo...eSAT Publishing House
1) A cyclone with wind speeds of 175-200 kph caused massive damage to the green cover of Gitam University campus in Visakhapatnam, India. Thousands of trees were uprooted or damaged.
2) A study assessed different types of damage to trees from the cyclone, including defoliation, salt spray damage, damage to stems/branches, and uprooting. Certain tree species were more vulnerable than others.
3) The results of the study can help in selecting more wind-resistant tree species for future planting and reducing damage from future storms.
Wind damage to buildings, infrastrucuture and landscape elements along the be...eSAT Publishing House
1) A visual study was conducted to assess wind damage from Cyclone Hudhud along the 27km Visakha-Bheemli Beach road in Visakhapatnam, India.
2) Residential and commercial buildings suffered extensive roof damage, while glass facades on hotels and restaurants were shattered. Infrastructure like electricity poles and bus shelters were destroyed.
3) Landscape elements faced damage, including collapsed trees that damaged pavements, and debris in parks. The cyclone wiped out over half the city's green cover and caused beach erosion around protected areas.
1) The document reviews factors that influence the shear strength of reinforced concrete deep beams, including compressive strength of concrete, percentage of tension reinforcement, vertical and horizontal web reinforcement, aggregate interlock, shear span-to-depth ratio, loading distribution, side cover, and beam depth.
2) It finds that compressive strength of concrete, tension reinforcement percentage, and web reinforcement all increase shear strength, while shear strength decreases as shear span-to-depth ratio increases.
3) The distribution and amount of vertical and horizontal web reinforcement also affects shear strength, but closely spaced stirrups do not necessarily enhance capacity or performance.
Role of voluntary teams of professional engineers in dissater management – ex...eSAT Publishing House
1) A team of 17 professional engineers from various disciplines called the "Griha Seva" team volunteered after the 2001 Gujarat earthquake to provide technical assistance.
2) The team conducted site visits, assessments, testing and recommended retrofitting strategies for damaged structures in Bhuj and Ahmedabad. They were able to fully assess and retrofit 20 buildings in Ahmedabad.
3) Factors observed that exacerbated the earthquake's impacts included unplanned construction, non-engineered buildings, improper prior retrofitting, and defective materials and workmanship. The professional engineers' technical expertise was crucial for effective post-disaster management.
This document discusses risk analysis and environmental hazard management. It begins by defining risk, hazard, and toxicity. It then outlines the steps involved in hazard identification, including HAZID, HAZOP, and HAZAN. The document presents a case study of a hypothetical gas collecting station, identifying potential accidents and hazards. It discusses quantitative and qualitative approaches to risk analysis, including calculating a fire and explosion index. The document concludes by discussing hazard management strategies like preventative measures, control measures, fire protection, relief operations, and the importance of training personnel on safety.
Review study on performance of seismically tested repaired shear wallseSAT Publishing House
This document summarizes research on the performance of reinforced concrete shear walls that have been repaired after damage. It begins with an introduction to shear walls and their failure modes. The literature review then discusses the behavior of original shear walls as well as different repair techniques tested by other researchers, including conventional repair with new concrete, jacketing with steel plates or concrete, and use of fiber reinforced polymers. The document focuses on evaluating the strength retention of shear walls after being repaired with various methods.
Monitoring and assessment of air quality with reference to dust particles (pm...eSAT Publishing House
This document summarizes a study on monitoring and assessing air quality with respect to dust particles (PM10 and PM2.5) in the urban environment of Visakhapatnam, India. Sampling was conducted in residential, commercial, and industrial areas from October 2013 to August 2014. The average PM2.5 and PM10 concentrations were within limits in residential areas but moderate to high in commercial and industrial areas. Exceedance factor levels indicated moderate pollution for residential areas and moderate to high pollution for commercial and industrial areas. There is a need for management measures like improved public transport and green spaces to combat particulate air pollution in the study areas.
Low cost wireless sensor networks and smartphone applications for disaster ma...eSAT Publishing House
This document describes a low-cost wireless sensor network and smartphone application system for disaster management. The system uses an Arduino-based wireless sensor network comprising nodes with various sensors to monitor the environment. The sensor data is transmitted to a central gateway and then to the cloud for analysis. A smartphone app connected to the cloud can detect disasters from the sensor data and send real-time alerts to users to help with early evacuation. The system aims to provide low-cost localized disaster detection and warnings to improve safety.
Coastal zones – seismic vulnerability an analysis from east coast of indiaeSAT Publishing House
This document summarizes an analysis of seismic vulnerability along the east coast of India. It discusses the geotectonic setting of the region as a passive continental margin and reports some moderate seismic activity from offshore in recent decades. While seismic stability cannot be assumed given events like the 2004 tsunami, no major earthquakes have been recorded along this coast historically. The document calls for further study of active faults, neotectonics, and implementation of improved seismic building codes to mitigate vulnerability.
This document discusses the assessment of seismic susceptibility of reinforced concrete (RC) buildings. It begins with an introduction to earthquakes and the importance of vulnerability assessment in mitigating earthquake risks and losses. It then describes modeling the nonlinear behavior of RC building elements and performing pushover analysis to evaluate building performance. The document outlines modeling RC frames and developing moment-curvature relationships. It also summarizes the results of pushover analyses on sample 2D and 3D RC frames with and without shear walls. The conclusions emphasize that pushover analysis effectively assesses building properties but has limitations, and that capacity spectrum method provides appropriate results for evaluating building response and retrofitting impact.
A geophysical insight of earthquake occurred on 21 st may 2014 off paradip, b...eSAT Publishing House
1) A 6.0 magnitude earthquake occurred off the coast of Paradip, Odisha in the Bay of Bengal on May 21, 2014 at a depth of around 40 km.
2) Analysis of magnetic and bathymetric data from the area revealed the presence of major lineaments in NW-SE and NE-SW directions that may be responsible for seismic activity through stress release.
3) Movements along growth faults at the margins of large Bengal channels, due to large sediment loads, could also contribute to seismic events by triggering movements along the faults.
Effect of hudhud cyclone on the development of visakhapatnam as smart and gre...eSAT Publishing House
This document discusses the effects of Cyclone Hudhud on the development of Visakhapatnam as a smart and green city through a case study and preliminary surveys. The surveys found that 31% of participants had experienced cyclones, 9% floods, and 59% landslides previously in Visakhapatnam. Awareness of disaster alarming systems increased from 14% before the 2004 tsunami to 85% during Cyclone Hudhud, while awareness of disaster management systems increased from 50% before the tsunami to 94% during Hudhud. The surveys indicate that initiatives after the tsunami improved awareness and preparedness. Developing Visakhapatnam as a smart, green city should consider governance
This document summarizes a product called H-HUTS that aims to provide sustainable disaster recovery housing. H-HUTS uses cardboard and origami-inspired modular construction to quickly provide temporary shelters after disasters. The cardboard shelters are designed to be upgraded into permanent homes over time using low-cost materials like shotcrete or concrete. The modular design allows for flexibility and community participation in construction. Testing has shown the shelters can withstand wind loads and provide adequate insulation. The goal of H-HUTS is to not just provide initial shelter but help disaster-affected communities regain permanency in housing and recover in the long-term.
Redefining brain tumor segmentation: a cutting-edge convolutional neural netw...IJECEIAES
Medical image analysis has witnessed significant advancements with deep learning techniques. In the domain of brain tumor segmentation, the ability to
precisely delineate tumor boundaries from magnetic resonance imaging (MRI)
scans holds profound implications for diagnosis. This study presents an ensemble convolutional neural network (CNN) with transfer learning, integrating
the state-of-the-art Deeplabv3+ architecture with the ResNet18 backbone. The
model is rigorously trained and evaluated, exhibiting remarkable performance
metrics, including an impressive global accuracy of 99.286%, a high-class accuracy of 82.191%, a mean intersection over union (IoU) of 79.900%, a weighted
IoU of 98.620%, and a Boundary F1 (BF) score of 83.303%. Notably, a detailed comparative analysis with existing methods showcases the superiority of
our proposed model. These findings underscore the model’s competence in precise brain tumor localization, underscoring its potential to revolutionize medical
image analysis and enhance healthcare outcomes. This research paves the way
for future exploration and optimization of advanced CNN models in medical
imaging, emphasizing addressing false positives and resource efficiency.
UNLOCKING HEALTHCARE 4.0: NAVIGATING CRITICAL SUCCESS FACTORS FOR EFFECTIVE I...amsjournal
The Fourth Industrial Revolution is transforming industries, including healthcare, by integrating digital,
physical, and biological technologies. This study examines the integration of 4.0 technologies into
healthcare, identifying success factors and challenges through interviews with 70 stakeholders from 33
countries. Healthcare is evolving significantly, with varied objectives across nations aiming to improve
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Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
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Comparative analysis between traditional aquaponics and reconstructed aquapon...bijceesjournal
The aquaponic system of planting is a method that does not require soil usage. It is a method that only needs water, fish, lava rocks (a substitute for soil), and plants. Aquaponic systems are sustainable and environmentally friendly. Its use not only helps to plant in small spaces but also helps reduce artificial chemical use and minimizes excess water use, as aquaponics consumes 90% less water than soil-based gardening. The study applied a descriptive and experimental design to assess and compare conventional and reconstructed aquaponic methods for reproducing tomatoes. The researchers created an observation checklist to determine the significant factors of the study. The study aims to determine the significant difference between traditional aquaponics and reconstructed aquaponics systems propagating tomatoes in terms of height, weight, girth, and number of fruits. The reconstructed aquaponics system’s higher growth yield results in a much more nourished crop than the traditional aquaponics system. It is superior in its number of fruits, height, weight, and girth measurement. Moreover, the reconstructed aquaponics system is proven to eliminate all the hindrances present in the traditional aquaponics system, which are overcrowding of fish, algae growth, pest problems, contaminated water, and dead fish.
Size effect of plain concrete beams–an experimental
1. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
__________________________________________________________________________________________
Volume: 02 Issue: 06 | Jun-2013, Available @ http://www.ijret.org 1047
SIZE EFFECT OF PLAIN CONCRETE BEAMS–AN EXPERIMENTAL
STUDY
T. Muralidhara Rao1
, T.D.Gunneswara Rao2
1
Dept.of Civil Engg., Vardhaman College of Engg., Hyderabad-501218. A.P., India. 09989214274
2
Dept of Civil Engg, NIT Warangal506004. A.P, India, 09912995173, tmuralidhararao@gmail.com, tdgtdg@gmail.com
Abstract
The paper analyses the size dependency of the fracture energy (GF) and the effective length of fracture process zone (Cf) of concrete
determined as per the Bazant’s Size effect method and RILEM Work-of-fracture methods. The fracture parameters (GF,Cf) are
determined by measuring the maximum loads of geometrically similar notched plain concrete (M25) specimens of different sizes in a
size ratio of 1:5 with different pre-cast notch depths (a/d=0.15, 0.30 and 0.45) under three point bending through load-deflection
curves. In each notch depth ratio, 15 beams are cast and tested with 03 similar specimens in each size of the beams. Total beams
tested are 45.The variation of both the fracture energy and the effective length of fracture process zone as a function of the specimen
size and notch depth is determined using Bazant’s Size effect method and RILEM Work-of-fracture method. Fracture energy and
Fracture process zone length determined by Size effect method are found to be decreasing with the increasing notch depth ratios.
Fracture energy calculated using Work-of-fracture method is increasing with the increase in size of specimen and decreasing with the
increasing notch depth ratios.
Keywords: Brittleness number, Characteristic size, Crack length, Effective length of fracture process of zone, Fracture
parameters, Fracture energy, Notch-depth ratio, Size effect.
-----------------------------------------------------------------***-----------------------------------------------------------------
1. INTRODUCTION
The size effect on structural strength is an important
phenomenon with a very old history. Unfortunately, despite
abundant experimental evidence, this phenomenon is still not
taken into account in most specifications of the design codes
for concrete structures, as well as the design practices.
Generally, concrete structures are designed based on the
strength of a standard specimen size. The actual concrete
strength of relatively larger structural members may be
significantly lower than that of the standard size. In fact, with
the increasing size of the specimens, the failure load increases
but the nominal stress decreases. By neglecting size effect,
predicted load capacity values are less conservative as the
member size increases. The size effect can be quantified by
comparing the stress at the maximum load of geometrically
similar specimens of different sizes with geometrically similar
notch ratios.
2. SIZE EFFECT METHOD
Bazant [1] proposed the size dependency of nominal strength
of geometrically similar concrete structures by the size effect
law. Fig 1 shows a typical three point bend test set up for the
determination of fracture parameters using Size effect method
[2].
N =
1
tBf
, where od
d
Where ft is the material tensile strength, is the brittleness
number, and B and d0 are empirical constants. The nominal
strength of two-dimensional similar structures is defined as
N = nc bd
Pu
Where cn is a coefficient introduced for convenience, Pu is the
ultimate load, b is the specimen thickness, and d is the
characteristic specimen size (i.e., height of the beam). When
is very small (e.g., <0.1), the behavior of a structure is
more ductile and the nominal strength of the structure
approaches the plastic or yield limit. But when b is very large
(e.g., >10), the behavior tends to be more brittle and the
nominal strength approaches the prediction by linear elastic
fracture mechanics (LEFM) [1].
To facilitate the evaluation of the constants in the size effect
law, the above equation can be written as
2. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
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Volume: 02 Issue: 06 | Jun-2013, Available @ http://www.ijret.org 1048
2
2
2
111
totN Bf
d
dBf
If the experimental data are arranged in a plot of X = d and Y
=
2
1
N
; a linear regression equation may be found as Y
= AX +C. Then B and do can be evaluated from A and C as
C
Bft
1
; od =
A
C
Size Effect Method -RILEM Recommendations [2] for
Fracture energy (Gf)and Effective length of Process zone
length(Cf)
The procedure for determining the fracture parameters using
size effect method consists of testing the geometrically similar
specimens under three point loading as shown in Fig.1. A
correction for the load carrying capacity of the specimen is
required to consider the influence of self-weight of the
member.
a) The corrected maximum loads
o
n
o
PP .......,,.........1 which
take the weight of the Specimens into account, have to be
calculated. If lj is almost the same as Sj,
gmPP jj
o
2
1
1
(j =1, 2 …n)
Where mj is the mass of specimen j, g = acceleration due to
gravity, and n = number of tests conducted.
b) Linear regression can be carried out by taking the ordinates
of Yj on Y-axis the ordinates of Xj on X-axis
Where
2
o
j
j
j
P
bd
Y
; Xj = dj
c) The slope and intercept of the regression line Y = AX + C
can be calculated using the following expressions.
Slope, A
j
j
j
jj
XX
YYXX
2
Intercept, C= XAY
Where
,
1
j
jX
n
X
, Y
j
jY
n
1
Where ( X ,Y ) = centroid of the data points. The plot of data
points is to be checked for linearity. If it is not linear, then
some errors or disturbing effects have probably occurred in the
test procedure.
d) The auxiliary values for the extrapolation are to be
calculated to very large specimen sizes for which linear elastic
fracture mechanics applies. For known values of relative crack
length, d
a
, where = crack length,
For S/d = 2.5
2
3
432
5.2
1
33.198.349.45.20.1
F
For S/d = 4
2
3
2
1
2
4
121
7.293.315.2199.1
F
For S/d = 8
432
8 25.1455.1371.712.211.1 F
Linear interpolation can be used for other values of s/d For
example,
For 4 <S/d <10
484
4
]4/[
FF
dS
FF
The non-dimensional energy release rate is
2
2
5.1 F
d
S
g
For αo = oa
/d, g (α = αo) is to be calculated.
e) Now, the fracture energy Gf (mean prediction) can be
calculated using the following expression:
3. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
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Volume: 02 Issue: 06 | Jun-2013, Available @ http://www.ijret.org 1049
AE
g
G
c
o
f
--------------------- (1)
2.1 Fracture Process Zone Length
The size-effect method makes it also possible to determine the
effective length Cf of the fracture process zone. This fracture
parameter represents the length of the equivalent linear elastic
crack that gives the same unloading compliance as the actual
crack in an infinitely large specimen at the peak load.
fC
=
o
o
g
g
'
od =
A
C
g
g
o
o
'
Where
og '
=
o
o
d
dg
3. WORK-OF-METHOD [3]
Based on a measured load-deflection curve of a fracture
specimen, typically a three point bend beam, the work of load
P (including the effect of its own weight) on the load-point
displacement δ in RILEM method is calculated as
PWf d
The fracture energy according to the RILEM definition,
dB
W
dG
o
f
of
1
,
Where
d
ao
o
Zdenek.P.Bazant and Mohammad.T.Kazemi [3] concluded
that fracture energy determined based on work-of-fracture
method is size dependent, though the RILEM
recommendations say that the work-of-fracture method is size
independent. Further, it was mentioned in three point bent
fracture specimens, the fracture energy according to the
RILEM definition is dependent on the notch depth also.
Sidney [4] Mindess concluded that the fracture energy (GF)
and Fracture toughness (KIC) increased considerably for the
largest beams tested. The largest beam size tested was
400mmx400mmx3360mm.
W.Brameshuber and H.K.Hilsdorf [5] found an increase of
fracture energy of about 20 percent when the beam depth was
increased from 100mm to 800mm.
F.H.Wittmann, H.Mihashi and N.Nomura [6] showed that the
fracture energy (GF) is influenced by various factors such as
the specimen size and the mix proportions. The strain
softening diagram was also analyzed and the possible
mechanism of size effect on fracture energy of concrete is
discussed.
4. EXPERIMENTAL PROGRAM
(i) Material Details
Cement conforming to ASTM C150 Type I with specific
gravity 3.15 is used for the concrete mix. Natural river sand
with specific gravity 2.60 meeting the requirements of ASTM
C-33 is used as fine aggregate. Crushed coarse aggregate
passing 4.75mm sieve and retained on 2.36mm sieve with
specific gravity 2.78 is used. The maximum aggregate size
used in the study is 4mm. The maximum size of the coarse
aggregate is limited to 4mm, as the smallest size of the set of
beams tested was 33mm (Crack free depth of a beam of height
60mm with notch ratio of 0.45). Potable water is used for
casting.
(ii) Casting
Cubes of 150mm size are used to determine the compressive
strength of concrete. Cylinders with 150 mm diameter and 300
mm length are used to determine the Modulus of Elasticity of
concrete. Prisms of 100mm x 100mm x 400mm (B x D x L)
size are adopted to determine the modulus of rupture. Moulds
of different dimensions are used for beams of different sizes.
A needle vibrator is used for compaction. The moulds are
tightly fit and all the joints are sealed by plaster of Paris in
order to prevent leakage of cement slurry through the joints.
The inner side of the moulds is thoroughly applied with oil.
For all notched specimens, notch plates (mild steel) of 2mm
thickness are used to make different notch depths at the centre
of each beam. The mix proportions are thoroughly mixed in a
concrete miller and the thoroughly mixed concrete is placed in
the moulds and compacted using needle vibrator and the top
surface is leveled with a trowel. The details of mix proportions
are listed in Table 1.All the specimens are cured for 28 days in
the curing tank. On 29th day, they are removed from the
curing tank and the specimens are allowed to dry for 04 hours
before testing. The experimental program is designed to study
the variation of fracture energy and the effective length of
fracture process zone of plain concrete beams under three-
point bending. Geometrically similar plain concrete beams
(M25) of different sizes with varying notch depth ratios are
cast.
Notch ratios of 0.15, 0.30 and 0.45 are used for the beams.
Beams are cast in three batches i.e., 15 beams in each batch
(a0/d=0.15, 0.30 and 0.45). Three similar beams are cast in
each beam size. Along with each batch of beams, 3 cubes,
3cylinders and 3prisms were also cast for the determination of
material properties compressive strength, Young’s modulus
4. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
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Volume: 02 Issue: 06 | Jun-2013, Available @ http://www.ijret.org 1050
and modulus of rupture respectively. The details of strength
properties of concrete are summarized in Table 2.
(iii) Test Results
The cured specimens were mounted on the Tinious Olsen
Universal Testing Machine (TOTM) and tested until failure. A
dial gauge with least count of 0.01mm is used to measure the
deflection under the central load point. The capacity of
Tinious Olsen Universal Testing Machine is 1780 kN. The
axis of the specimen is carefully aligned at the center of the
loading frame. For determining the fracture parameters with
the help of size effect method, regression plots were prepared
and were presented in Table3, Fig.2. The regression plots
consisted
20
1
bd
P
on Y-axis and size (d) on X-axis. The
regression equation is presented in the form of CAXY .
The characteristic size of the tested beams is reported as
A
C
d 0
and the numerator in size effect law C
Bft
1
.
Size effect plots were prepared on logarithmic scale and were
presented in Fig.3 (for A, B and C series). Data pertaining to
the size effect law variations is presented in Table.4 for all
series of beams tested in this investigation. From the size
effect method, the fracture parameters viz., fracture energy
and effective length of fracture process zone were determined
and reported in Table 5. From the load deflection response of
the tested specimens fracture energy was calculated using
work of fracture method. The test results are tabulated in
Table.6. All the tested beams (Series A, Series B and Series C)
are given in Fig 6.
5. DISCUSSION
The fracture energy determined by the size effect method is
the mean prediction for a particular notch depth ratio. From
equation (1), it can be observed that for a given notched beam
(
c
o
E
g
is a constant term) the fracture energy depends on
the slope of the regression line (A). The fracture energy is
inversely proportional to the slope of the regression line. In the
present investigation, it is found that the slope of the
regression line (A) is increased with the increase in the notch
depth ratio. It indicates that the increase in notch depth ratio
decreases the fracture energy. In other words, increase in crack
length of a structure requires less fracture energy for extending
the crack (vide Fig.4). A decrease in fracture energy for crack
extension indicates the brittleness of the structure. Thus it can
be concluded that a crack present in a structure pushes the
structure to fail in a brittle manner when the crack length (may
be referred as critical crack length) approaches a particular
value. From Table 5 and Fig.5, it is clear that the effective
length of fracture process zone Cf decreased with the notch
depth ratio. A higher fracture process zone indicates a ductile
failure in a structure allowing more dissipation of energy
through FPZ. A small FPZ indicates a brittle failure. Thus
with the increase in the notch depth ratio or increase in crack
length reduces the FPZ, thereby pushing the structure into a
brittle failure state.
The Size effect law (SEL) graphs shown in Fig 3 represent a
gradual transition from the strength criterion ( tN Bf
i.e.,
1
0
d
d
) to the energy criterion of LEFM (
1
0
d
d
).
Size effect plots were prepared for the tested beams with
varying notch depth ratio. The size effect plot was presented in
Fig.3. From this plot it can further be said that the increase in
the notch depth ratio increases the 0d
d
, making the structure
fail by brittle manner wherein energy criterion of failure can
be applied.
5.1 Brittleness number
The Brittleness number as indicated by 0d
d
characterizes
the brittleness of the member. Quasi-brittle structures [7] are
those for which 101.0 . If 1.0 , then the failure
may be analyzed on the basis of the strength criterion and
if
10 , then the failure may be analyzed according to the
Linear Elastic Fracture Mechanics [8]. For 101.0 , the
nonlinear fracture mechanics should be used [9]. From Table
5, it is clear that the increase in the notch ratio decreases the
characteristic dimension do thereby increasing the brittleness
of the member. In other words, it can be stated that an increase
in the crack length (due to external forces) increases the brittle
number of the element. Thus brittleness of concrete depends
more on the crack size or crack length.
Table 6 shows that the fracture energy (GF) varied with the
size of the specimen and the notch ratio α = (ao/d). Fracture
energy, GF decreased with the increased notch depth ao and
increased with the increased size of the specimen (d) and
hence this fracture energy is not size independent. However, it
has been stated that the application of the boundary effect
concept to the test results of GF indeed gives a specific
fracture energy value GF that is independent of the size and
shape of the test specimen [10]. The fracture energy (GF)
obtained by Work-of-fracture method and the size effect was
found to be varying as confirmed by Bazant and Becq-
Giraudon [11]. The ratio of fracture energy (GF) calculated
5. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
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Volume: 02 Issue: 06 | Jun-2013, Available @ http://www.ijret.org 1051
using RILEM Work-of-fracture method and that of fracture
energy (Gf) calculated using Size effect method is found to be
more than 2.0 in case of beam series A and series B and 1.98
in case of beam series C respectively. The details of (GF/Gf)
ratios are given in Table 7. Size effect method (SEM) is
simpler and needs less sophisticated equipment. Where as
work-of-fracture method needs more sophisticated equipment
and is tedious. It is observed that the fracture energy obtained
from both these methods is size dependent. Thus Size effect
method (SEM) is more suitable than work-of-fracture method
for estimating the fracture energy, due to the simplicity of the
test procedure. More tests are needed in this direction
(comparing SEM and Work of fracture method) to verify the
size dependency of fracture energy using highly brittle
concrete (very high strength concrete) as well as highly ductile
concrete (SIFCON). Till today, there is a suspicion that the
difference between the two methods in estimating the fracture
energy might be due to some innate fault of one or other
method [12]. In these circumstances, it is convenient to assess
the fracture energy parameters through SEM and can be
modified by a suitable factor, if work-of-fracture method is
proved to be a correct one.
CONCLUSIONS
Based on the tests on notched concrete members of different
sizes and notch ratios, the following conclusions were drawn.
1. Increase in the notch ratio (a/d) increases the
brittleness of the member, in other words, increase in
crack length in a structure pushes the structure to
behave in a brittle manner.
2. Effective length of fracture process zone (Cf)
decreases with the increase in the size of the member.
3. The fracture energy (GF) obtained based on work-of-
fracture method is nearly twice the fracture energy
(Gf) obtained based on Size effect method (SEM).
REFERENCES
[1]. F.P. Zhou, R.V. Balendran, and A.P. Jeary, Size effect on
flexural, splitting tensile and Torsional strengths of High
Strength concrete, Cement and Concrete Research, Vol.28,
No.12, pp.1725–1736, 1998.
[2]. Size-effect method for determining fracture energy and
process zone size of concrete: RILEM DRAFT
RECOMMENDATIONS, Materials and Structures, 23, 461-
465.
[3]. Zdenek P.Bazant and Mohammad T.Kazemi, Size
dependence of concrete fracture energy determined by RILEM
Work of fracture method, International Journal of Fracture 51:
121-138, 1991.
[4]. Sidney Mindess, The effect of specimen size on the
fracture energy of concrete, Cement and Concrete Research,
Vol. 14, Issue 3, May1984, pp. 431-436.
[5]. W.Brameshuber and H.K.Hilsdorf, Influence of ligament
length and stress state on fracture energy of concrete,
Engineering Fracture Mechanics, Vol.35, Issues 1-3, 1990,
pp.95-106.
[6]. F.H.Wittmann, H.Mihashi and N.Nomura, Size effect on
fracture energy of concrete, Engineering Fracture Mechanics,
Vol.35, Issues 1-3, 1990, pp.107-115.
[7]. RILEM TC QFS Quasi-brittle fracture scaling and size
effect- Final report, Materials and Structures, Vol.37, October
2004, pp 547-568.
[8]. Z.P.Bazant and M.T.Kazemi, Determination of fracture
energy, process zone length and brittleness number from size
effect with application to rock and Concrete, International
Journal of fracture 44:1990.
[9]. Ricardo A.Einsfeld, Marta S.L.Velasco, Fracture
parameters of high performance Concrete, Cement and
Concrete Research, 36 (2006) 576 – 583.
[10]. Kai Duan, Xiaozhi Hu, Folker H. Wittmann, Size effect
on specific fracture energy of concrete, Engineering Fracture
Mechanics, 74 (2007) 87-96.
[11]. Zdenek P.Bazant, Emilie Becq-Giraudon, Statistical
prediction of fracture parameters of concrete and implications
for choice of testing standard, Cement and Concrete Research,
32 (2002) 529-556.
[12]. Zdenek P.Bazant, Analysis of work of fracture method
for measuring fracture energy of concrete, Journal of
Engineering Mechanics, Vol.122, No.2, February 1996.
6. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
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Volume: 02 Issue: 06 | Jun-2013, Available @ http://www.ijret.org 1052
Table-1: Details of Mix Proportions and Beams
Table-2: Mechanical Properties
Table-3: Linear Regression Data & Corresponding Graphs
Beam
Series
Grade of
Concrete
Notch
depth
ratio
Mix Proportions (Kgs per cubic meter of
concrete)
Dimensions of
beam Specimens
(l x b x d)
Designation
(ao/d) Cement Fine
Aggregate
Coarse
Aggregate
water mm x mm x mm
Series A M25 0.15 460 707.397 884.549 207 360x80x60 N/60/0.15
M25 0.15 460 707.397 884.549 207 540x80x90 N/90/0.15
M25 0.15 460 707.397 884.549 207 810x80x135 N/135/0.15
M25 0.15 460 707.397 884.549 207 1215x80x202.5 N/202.5/0.15
M25 0.15 460 707.397 884.549 207 1822.5x80x303.75 N/303.75/0.15
Series B M25 0.30 460 707.397 884.549 207 360x80x60 N/60/0.30
M25 0.30 460 707.397 884.549 207 540x80x90 N/90/0.30
M25 0.30 460 707.397 884.549 207 810x80x135 N/135/0.30
M25 0.30 460 707.397 884.549 207 1215x80x202.5 N/202.5/0.30
M25 0.30 460 707.397 884.549 207 1822.5x80x303.75 N/303.75/0.30
Series C M25 0.45 460 707.397 884.549 207 360x80x60 N/60/0.45
M25 0.45 460 707.397 884.549 207 540x80x90 N/90/0.45
M25 0.45 460 707.397 884.549 207 810x80x135 N/135/0.45
M25 0.45 460 707.397 884.549 207 1215x80x202.5 N/202.5/0.45
M25 0.45 460 707.397 884.549 207 1822.5x80x303.75 N/303.75/0.45
Beam
Series
Wet density
(kN/m3
)
Cube
Compressive
strength (fck)
MPa
Modulus of rupture on
Prisms (fbt) MPa
Modulus of Elasticity (E)
Mpa
Series A 24.067 33.185 3.603 25153.333
Series B 23.563 40.444 4.242 27527.500
Series C 24.067 26.815 3.869 28289.000
Beam
Size(d)
(mm)
SERIES A SERIES B SERIES C
Y=
(bd/po)2
MPa-2
Y=
(bd/po)2
MPa-2
Y=
(bd/po)2
MPa-2
Y=
(bd/po)2
MPa-2
Y=
(bd/po)2
MPa-2
Y=
(bd/po)2
MPa-2
Y=
(bd/po)2
MPa-2
Y=
(bd/po)
2
MPa-2
Y=
(bd/po)
2
MPa-2
60 4.29 4.19 4.39 7.41 8.73 8.73 16.47 15.73 14.38
90 4.81 4.97 5.06 8.62 8.06 8.24 21.08 20.35 19.01
135 5.54 5.68 6.12 9.64 9.34 8.27 24.54 22.78 26.54
202.5 6.86 6.39 7.11 12.39 13.67 12.85 30.2 28.57 29.64
303.75 7.81 7.67 7.57 13.64 13.75 16.89 37.08 37.59 37.59
7. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
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Volume: 02 Issue: 06 | Jun-2013, Available @ http://www.ijret.org 1053
Table-4: Size Effect Law Data & Corresponding Graphs
Table-5: Fracture Parameters From Size Effect Method
Table-6: Fracture Energy From Work Of Fracture Method
Table-7: Fracture Energy from Size Effect Method & RILEM Work Of Fracture Method
Beam Series
Mean prediction of fracture energy(N-m/m2
)
Ratio of (GF/Gf)Size Effect Method(Gf)
RILEM Work-of-
fracture Method(GF)
Series A 59.17 131.93 2.23
Series B 49.11 107.16 2.18
Series C 43.5 85.95 1.98
Depth
of
beam SERIES A SERIES B SERIES C
mm Log(d/do) Log(σN/Bft) Log(d/do) Log(σN/Bft) Log(d/do) Log(σN/Bft)
60 -0.652 -0.044 -0.628 -0.046 -0.358 -0.079
90 -0.475 -0.063 -0.452 -0.066 -0.182 -0.109
135 -0.299 -0.088 -0.276 -0.092 -0.0056 -0.149
202.5 -0.123 -0.122 -0.099 -0.127 0.17 -0.197
303.75 0.053 -0.164 0.076 -0.17 0.347 -0.254
Beam
series
A
(mm-1
MPa-2
) C (MPa-2
) do (mm)
B ft
MPa (ao/d)
Fracture energy
(Mean prediction)
(Gf) N.m/m2
.
Effective length of
FPZ
(Mean prediction)
(Cf) mm.
Series A 0.0138 3.7114 268.942 0.519 0.15 59.17 60.99
Series B 0.0297 5.9780 201.283 0.409 0.30 49.11 50.27
Series C 0.0862 11.788 136.752 0.291 0.45 43.50 34.66
Size of beam(d) Fracture energy, GF
mm
(N-m/m2
)
Series A Series B Series C
60 75.62 55.61 41.86
90 102.13 83.87 57.51
135 130.69 109.26 86.99
202.5 159.05 126.46 106.7
303.75 192.14 160.61 136.68
8. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
__________________________________________________________________________________________
Volume: 02 Issue: 06 | Jun-2013, Available @ http://www.ijret.org 1054
0
5
10
15
20
25
30
35
40
0 100 200 300 400
Depth of beam,d(mm)
Y=(bd/po)2=(1/SigmaN)2
Series A
Series B
Series C
Linear
(Series A)
Linear
(Series B )
Linear
(Series C)
Fig-1: Typical three point bending test set up
Fig-2: Linear Regression Graphs for Series A, Series B, Series C Beams
Fig-3: Size effect law graph for Series A, Series B, Series C Beams
9. IJRET: International Journal of Research in Engineering and Technology ISSN: 2319-1163
__________________________________________________________________________________________
Volume: 02 Issue: 06 | Jun-2013, Available @ http://www.ijret.org 1055
Series C
Series B
Series A
0
10
20
30
40
50
60
70
0 0.1 0.2 0.3 0.4 0.5
Notch depth ratio, ao/d
FractureProcessZoneLength,Cf
(mm)
Series C
Series B
series A
0
10
20
30
40
50
60
70
0 0.2 0.4 0.6
Notch depth ratio, ao/dFractureEnergy,Gf(N-m/m2)
Fig-4: Fracture energy (Mean prediction) variation with Notch depth ratio (ao/d)
Fig-5: Effective length of Fracture process zone variation with Notch depth ratio (a/d)
Fig-6: Tested beams Series A, Series B, Series C