The document describes developing a nondestructive testing method to detect defects in agricultural machinery parts. A four-point probe potential drop technique was used to measure voltage changes caused by internal cracks or defects. Tests were conducted on mild steel, stainless steel, and carbon steel samples with varying crack depths. The results showed that voltage drop increased with resistance and differed by material composition. A computer program was created to calculate resistivity and voltage drop from the experimental data, allowing defects to be detected nondestructively.
The document presents research on the compressive behavior and strength of cold-formed steel lipped channel studs and stud-track sections. Experimental testing was conducted on 19 specimens and found that stud-track sections had 20-27% higher strength than studs alone. Finite element analysis of a 300mm stud specimen closely matched experimental results. The conclusion is that initial geometric imperfections significantly reduce stud strength, while connecting studs with track at the ends increases strength and consistency.
IRJET- Development of Mathematical Models to Predict Weld Bead Geometry of Bu...IRJET Journal
This document describes a study that developed mathematical models to predict the weld bead geometry (penetration, width, and height) of butt welded high-strength low-alloy steel plates using submerged arc welding. Face-centered central composite design was used to construct response surface models based on welding parameters including voltage, wire feed rate, and trolley speed. The models found that wire feed rate had the strongest influence on the responses. Experiments were conducted according to the design and responses were recorded and used to develop regression equations to model each geometric parameter in terms of the input factors. The models were found to adequately explain the variations in the results.
This research was a part of my Dual Degree Thesis and presented at The Minerals Metals and Materials Society Annual Meeting and Conference held at Seattle, WA in 2010.
The document summarizes research characterizing the forming behavior of aluminum alloy AA5754 at elevated temperatures. Key findings from tensile and forming tests are:
1) Yield strength, strain hardening exponent, and flow stress decrease with increasing temperature, while elongation increases.
2) Warm forming from 100-250°C improves formability over room temperature forming.
3) A test setup was developed to evaluate forming limits at elevated temperatures up to 250°C.
This thesis experimentally and analytically investigates the buckling behavior of graphite/polyimide sandwich panels under edgewise compression loading. Material properties of the panel constituents were determined through flatwise tension and sandwich beam flexure tests. Buckling specimens of varying core thicknesses were tested to investigate failure modes. Specimens with the thinnest core failed by overall buckling near analytical predictions, while thicker cores failed by face wrinkling. Several buckling formulas for wrinkling were found to be unconservative. Recommended wrinkling equations are presented based on the test results. In conclusion, the buckling behavior of the graphite/polyimide sandwich panels was characterized experimentally and compared favorably to analytical predictions.
Plasma arc cutting parameters using taguchi methodchiragkolambe
In this paper, we have tested on a plasma arc
cutting machine but by using the Taguchi method. This
machine is accurate, high finishing. This process is very
cheap than another process like laser cutting. In the market,
this process has a high demand. In this paper, we will go to
study the Cutting Speed and Arc Gap and another import
factor in this process are using the Taguchi method by using
Minitab 17. We went Analysis Taguchi Analysis: surface
roughness, kerf versus speed, ... ideas, air gap. By using this
method ANOVO we will find General Linear Model: surface
roughness versus speed, ... ides, air gap In this research we
will use Mild Steel E350
This document discusses machining processes and metal cutting. It begins with an overview of common machining processes like turning and milling. It then covers topics such as orthogonal cutting, chip formation, different chip types, cutting forces, temperatures in cutting, tool geometry and wear. Diagrams illustrate cutting tool geometry, forces acting on tools, chip formation mechanisms, and experimental data on cutting parameters for different materials. The document provides information on machining processes and metal cutting for engineering materials.
Reliability Analysis on Shear Strength of RC Beams and Sensitivity AnalysisIRJET Journal
This document summarizes research analyzing the shear strength of reinforced concrete beams. Six series of beam test data were collected from literature and their test results were compared to shear force predictions from four empirical formulas in codes like ACI 318, BS8110, IS 456, and a formula by Bazant considering size effects. The findings show that Bazant's size effect formula gives very conservative results, while IS 456 and ACI 318 reasonably estimate shear strength at failure but not for first crack appearance in some cases. An attempt was made to establish probability distributions and conduct reliability analysis to characterize randomness in shear strength and perform sensitivity analysis on basic variable influences. In conclusion, the study compared experimental beam data to code-based predictions to evaluate shear strength modeling
The document presents research on the compressive behavior and strength of cold-formed steel lipped channel studs and stud-track sections. Experimental testing was conducted on 19 specimens and found that stud-track sections had 20-27% higher strength than studs alone. Finite element analysis of a 300mm stud specimen closely matched experimental results. The conclusion is that initial geometric imperfections significantly reduce stud strength, while connecting studs with track at the ends increases strength and consistency.
IRJET- Development of Mathematical Models to Predict Weld Bead Geometry of Bu...IRJET Journal
This document describes a study that developed mathematical models to predict the weld bead geometry (penetration, width, and height) of butt welded high-strength low-alloy steel plates using submerged arc welding. Face-centered central composite design was used to construct response surface models based on welding parameters including voltage, wire feed rate, and trolley speed. The models found that wire feed rate had the strongest influence on the responses. Experiments were conducted according to the design and responses were recorded and used to develop regression equations to model each geometric parameter in terms of the input factors. The models were found to adequately explain the variations in the results.
This research was a part of my Dual Degree Thesis and presented at The Minerals Metals and Materials Society Annual Meeting and Conference held at Seattle, WA in 2010.
The document summarizes research characterizing the forming behavior of aluminum alloy AA5754 at elevated temperatures. Key findings from tensile and forming tests are:
1) Yield strength, strain hardening exponent, and flow stress decrease with increasing temperature, while elongation increases.
2) Warm forming from 100-250°C improves formability over room temperature forming.
3) A test setup was developed to evaluate forming limits at elevated temperatures up to 250°C.
This thesis experimentally and analytically investigates the buckling behavior of graphite/polyimide sandwich panels under edgewise compression loading. Material properties of the panel constituents were determined through flatwise tension and sandwich beam flexure tests. Buckling specimens of varying core thicknesses were tested to investigate failure modes. Specimens with the thinnest core failed by overall buckling near analytical predictions, while thicker cores failed by face wrinkling. Several buckling formulas for wrinkling were found to be unconservative. Recommended wrinkling equations are presented based on the test results. In conclusion, the buckling behavior of the graphite/polyimide sandwich panels was characterized experimentally and compared favorably to analytical predictions.
Plasma arc cutting parameters using taguchi methodchiragkolambe
In this paper, we have tested on a plasma arc
cutting machine but by using the Taguchi method. This
machine is accurate, high finishing. This process is very
cheap than another process like laser cutting. In the market,
this process has a high demand. In this paper, we will go to
study the Cutting Speed and Arc Gap and another import
factor in this process are using the Taguchi method by using
Minitab 17. We went Analysis Taguchi Analysis: surface
roughness, kerf versus speed, ... ideas, air gap. By using this
method ANOVO we will find General Linear Model: surface
roughness versus speed, ... ides, air gap In this research we
will use Mild Steel E350
This document discusses machining processes and metal cutting. It begins with an overview of common machining processes like turning and milling. It then covers topics such as orthogonal cutting, chip formation, different chip types, cutting forces, temperatures in cutting, tool geometry and wear. Diagrams illustrate cutting tool geometry, forces acting on tools, chip formation mechanisms, and experimental data on cutting parameters for different materials. The document provides information on machining processes and metal cutting for engineering materials.
Reliability Analysis on Shear Strength of RC Beams and Sensitivity AnalysisIRJET Journal
This document summarizes research analyzing the shear strength of reinforced concrete beams. Six series of beam test data were collected from literature and their test results were compared to shear force predictions from four empirical formulas in codes like ACI 318, BS8110, IS 456, and a formula by Bazant considering size effects. The findings show that Bazant's size effect formula gives very conservative results, while IS 456 and ACI 318 reasonably estimate shear strength at failure but not for first crack appearance in some cases. An attempt was made to establish probability distributions and conduct reliability analysis to characterize randomness in shear strength and perform sensitivity analysis on basic variable influences. In conclusion, the study compared experimental beam data to code-based predictions to evaluate shear strength modeling
Stress and Durability Analysis of Threaded Connections in a Cast Aluminum Cyl...Altair
Bolted connections involve sharp notched components that are therefore sensitive to fatigue loading. In internal combustion engines, the journal bearings of the crankshaft are supported by bearing caps which are bolted to the cylinder block. These threaded connections are a fatigue concern as cracking may be experienced on dynamometer tests of new engines. The critical element of this application however is not the steel studs rather the threaded bolt holes in the cast engine block. While the nominal stress concept is applicable to the fatigue design of studs, a local stress approach has to be adopted to assess the fatigue strength of threaded bolt holes.
This paper addresses the fatigue design of this kind of threaded connection. Initially alternate methods of FE modeling and analysis of threaded joints by the local approach are critically examined. The parallel development of a simplified experimental test system involving a threaded hole in cast AlSi7 is described and used to generate baseline fatigue data under known loading conditions. The fatigue behavior of the experimental system is then analyzed on the basis of alternate FE models and post processing approaches. Finally, recommendations for the accurate and computationally efficient FE modeling and durability analysis of threaded connections in cast aluminum cylinder block are outlined.
Speakers
Marco Bersella, Engineer, TP Engineering srl
The document describes research on the effects of workpiece size on stock loss and edge radiusing during centrifugal barrel finishing processes. Equations are presented showing that smaller parts deburr much slower than larger parts, and that radius generation is an exponential function of time while stock losses vary linearly with time. The effect of initial burr size on edge radiusing is also modeled empirically. Data from tests on steel, aluminum and stainless steel workpieces show that accounting for part size provides a better model for predicting stock removal and edge finishing results during centrifugal barrel deburring.
This document presents the design of an iPad weight scale mechanism. It begins with outlining the objectives and scope, which include low cost, accuracy, compact size, and ease of use. It then reviews literature on mechanisms like the parallelogram linkage and slider-crank mechanism. Several preliminary design alternatives are considered and evaluated. The detailed design section presents the selection of a parallelogram with slider-crank mechanism and stylus design. Mathematical analysis is conducted in MATLAB. The mechanism is modeled in SOLIDWORKS and prototype testing shows it can accurately measure weights from 0-427.5 grams.
Determination Material Properties and Fracture Parameters of Triangular holed...Ashvini Kumar
In this project material properties and fracture parameters of aluminum samples are determined. This involves
- finding material properties of plane aluminum sample
- Determine fracture parameters and failure regions of single triangular hole in aluminum plate
-Find minimum distance between two symmetrical triangular holes to ensure no failure occurs between the two holes in ABAQUS
-Determine fracture parameters and failure regions of double triangular holed aluminium plate employing the minimum distance between the holes.
This document discusses surface engineering and manufacturing processes. It covers topics such as surface structure, surface finish terminology, surface roughness measurement, adhesion, friction, lubrication, wear mechanisms like abrasive and adhesive wear, thermal spraying, vapor deposition, electroplating, and burnishing. Figures and tables illustrate concepts like surface layer structure, surface roughness parameters, coefficient of friction for different processes, and wear modeling.
This document discusses methods for performing gauge repeatability and reproducibility (GR&R) tests on surface metrology equipment. It finds that GR&R values are often over 100% due to within-part variation rather than instrument error. Using a uniform sinusoidal specimen eliminates much of the within-part variation, resulting in more accurate GR&R values typically under 10%. The document also provides a method to determine the optimal number of measurements needed per part based on the surface variation and tolerance.
Sheet Metal Forming (MIT 2.008x Lecture Slides)A. John Hart
Slides accompanying 2.008x* video module on Sheet Metal Forming, Prof. David Hardt, MIT, 2016.
*Fundamentals of Manufacturing Processes on edX: https://www.edx.org/course/fundamentals-manufacturing-processes-mitx-2-008x
IRJET- Experimental Investigation of AISI 1015 Steel Plate in Milling by Resp...IRJET Journal
This document presents an experimental investigation into milling of AISI 1015 steel plate using response surface methodology. Experiments were conducted varying cutting speed, feed rate, and depth of cut. Response surface regression models were developed to predict surface roughness and material removal rate based on the cutting parameters. The models were found to explain over 94% of the variation in surface roughness and over 96% of the variation in material removal rate. Various tests confirmed that the models were statistically valid and adequately represented the relationships between the cutting parameters and responses.
This document summarizes key aspects of thermo compression bonding (TCB) technology from the perspective of a machine vendor. It discusses three core TCB capabilities that are essential for high yield: accuracy, co-planarity, and sophisticated bond control. Maintaining high accuracy during temperature ramping from cold to hot states is critical. Co-planarity must also be maintained during temperature ramping to avoid yield issues. Sophisticated hybrid bond control, as used in the TC-CUF process, tightly controls bond line thickness despite thermal expansion movements.
The document describes a study on the mechanical properties of friction stir processed AA5754 sheet metal at different temperatures and strain rates. The objectives were to characterize the tensile properties of FSPed and base metal sheets under various conditions and develop a Johnson Cook model to predict flow stress. Tensile tests were conducted on FSPed and base metal specimens at temperatures from room temperature to 400°C and crosshead velocities from 1-200mm/min. The results showed that both yield strength and ultimate tensile strength generally decreased with increasing temperature and strain rate for both materials. The FSPed material exhibited higher ductility than the base metal across most test conditions.
Slides accompanying 2.008x* video module on Casting, Prof. John Hart, MIT, 2016.
*Fundamentals of Manufacturing Processes on edX: https://www.edx.org/course/fundamentals-manufacturing-processes-mitx-2-008x
Thermoforming (MIT 2.008x Lecture Slides)A. John Hart
Slides accompanying 2.008x* video module on Thermoforming, Prof. John Hart, MIT, 2016.
*Fundamentals of Manufacturing Processes on edX: https://www.edx.org/course/fundamentals-manufacturing-processes-mitx-2-008x
Variation and Quality (2.008x Lecture Slides)A. John Hart
Slides accompanying 2.008x* video module on Variation and Quality, Prof. John Hart, MIT, 2016.
*Fundamentals of Manufacturing Processes on edX: https://www.edx.org/course/fundamentals-manufacturing-processes-mitx-2-008x
This document summarizes the work progress of a group project on welding and characterization of Ti-5Al-2.5Sn alloy. The group members are Umer Shahab, Talha Nasir Khan Lodhi, and Mian Muhammad Hussain, advised by Dr. Fahd Nawaz and co-advised by Dr. Imran Khan. The document outlines that wire EDM, electron beam welding, tensile testing, impact testing, microscopy, and residual stress testing via the hole-drill method were performed on the alloy. Key results mentioned include the tensile and impact test data, microstructural images showing the fusion zone, heat affected zone and base metal, and that residual stress distribution
The document summarizes research on structurally retrofitting reinforced concrete circular columns using carbon fiber reinforced polymer (CFRP). Finite element modeling was used to simulate column tests and compare results to design guidelines. The modeling captured material behavior accurately. Guidelines could be improved by better defining key parameters like confining pressure. Further research is needed on inclined wrapping schedules and other factors' effects.
The document provides information on various aspects of spot welding including:
- Definitions of key terms like spot weld, welding control, and the importance of force between electrodes.
- Explanations of spot welding principles involving resistance heating when current passes through interfaces of stacked metals joined by electrodes applying pressure.
- Advantages of spot welding as the quickest and most economical method for joining metals requiring no filler medium.
- Details on TPM system pillars like autonomous maintenance, planned maintenance, quality maintenance, and focused improvement to maintain production quality and equipment lifespan.
"Here Is Streaming http://www.watchtheboxing.net/ Mayweather vs Berto will be taking place on September 12 at MGM Grand Arena through the http://www.watchtheboxing.net/ In the main event, Mayweather and Berto will have to make the welterweight limit of 147 pounds.
Watch Live Stream On Android,Mac Ios,Tab,Windows Phones Or Other Digital Devices
The Mayweather vs. Pacquiao weigh-in takes place at 6 p.m. ET at the MGM Grand in Las Vegas, Nev., and the video is above."
El documento presenta los resultados de una encuesta realizada a 109 estudiantes de secundaria sobre su uso de las redes sociales. La mayoría de los estudiantes usan redes sociales como WhatsApp e Instagram a diario y tienen entre 100 y 600 contactos, aunque no todos los conocen. Algunos estudiantes publican información personal como fotos y detalles sobre su familia sin darse cuenta de los posibles riesgos. La encuesta revela la necesidad de enseñar a los estudiantes a usar las redes sociales de forma segura y responsable.
We have reason to believe that the SEC already has Qihoo on its radar. Given the information presented in this report, along with other issues that we have omitted, we believe that Qihoo will be delisted from the NYSE and management charged with securities fraud.
Solutions Overview for Public TransportWestbase.io
Public transport organisations are rapidly expanding their on-the-road technology in order to deliver improved efficiencies and to expand customer service capabilities. From passenger WiFi, to improved scheduling notifications, connectivity is a key enabler of this. Offering simple installation and integration with existing network infrastructure, 3G/4G solutions can deliver superfast, reliable and secure connectivity anywhere – a perfect solution for mobile applications.
Stress and Durability Analysis of Threaded Connections in a Cast Aluminum Cyl...Altair
Bolted connections involve sharp notched components that are therefore sensitive to fatigue loading. In internal combustion engines, the journal bearings of the crankshaft are supported by bearing caps which are bolted to the cylinder block. These threaded connections are a fatigue concern as cracking may be experienced on dynamometer tests of new engines. The critical element of this application however is not the steel studs rather the threaded bolt holes in the cast engine block. While the nominal stress concept is applicable to the fatigue design of studs, a local stress approach has to be adopted to assess the fatigue strength of threaded bolt holes.
This paper addresses the fatigue design of this kind of threaded connection. Initially alternate methods of FE modeling and analysis of threaded joints by the local approach are critically examined. The parallel development of a simplified experimental test system involving a threaded hole in cast AlSi7 is described and used to generate baseline fatigue data under known loading conditions. The fatigue behavior of the experimental system is then analyzed on the basis of alternate FE models and post processing approaches. Finally, recommendations for the accurate and computationally efficient FE modeling and durability analysis of threaded connections in cast aluminum cylinder block are outlined.
Speakers
Marco Bersella, Engineer, TP Engineering srl
The document describes research on the effects of workpiece size on stock loss and edge radiusing during centrifugal barrel finishing processes. Equations are presented showing that smaller parts deburr much slower than larger parts, and that radius generation is an exponential function of time while stock losses vary linearly with time. The effect of initial burr size on edge radiusing is also modeled empirically. Data from tests on steel, aluminum and stainless steel workpieces show that accounting for part size provides a better model for predicting stock removal and edge finishing results during centrifugal barrel deburring.
This document presents the design of an iPad weight scale mechanism. It begins with outlining the objectives and scope, which include low cost, accuracy, compact size, and ease of use. It then reviews literature on mechanisms like the parallelogram linkage and slider-crank mechanism. Several preliminary design alternatives are considered and evaluated. The detailed design section presents the selection of a parallelogram with slider-crank mechanism and stylus design. Mathematical analysis is conducted in MATLAB. The mechanism is modeled in SOLIDWORKS and prototype testing shows it can accurately measure weights from 0-427.5 grams.
Determination Material Properties and Fracture Parameters of Triangular holed...Ashvini Kumar
In this project material properties and fracture parameters of aluminum samples are determined. This involves
- finding material properties of plane aluminum sample
- Determine fracture parameters and failure regions of single triangular hole in aluminum plate
-Find minimum distance between two symmetrical triangular holes to ensure no failure occurs between the two holes in ABAQUS
-Determine fracture parameters and failure regions of double triangular holed aluminium plate employing the minimum distance between the holes.
This document discusses surface engineering and manufacturing processes. It covers topics such as surface structure, surface finish terminology, surface roughness measurement, adhesion, friction, lubrication, wear mechanisms like abrasive and adhesive wear, thermal spraying, vapor deposition, electroplating, and burnishing. Figures and tables illustrate concepts like surface layer structure, surface roughness parameters, coefficient of friction for different processes, and wear modeling.
This document discusses methods for performing gauge repeatability and reproducibility (GR&R) tests on surface metrology equipment. It finds that GR&R values are often over 100% due to within-part variation rather than instrument error. Using a uniform sinusoidal specimen eliminates much of the within-part variation, resulting in more accurate GR&R values typically under 10%. The document also provides a method to determine the optimal number of measurements needed per part based on the surface variation and tolerance.
Sheet Metal Forming (MIT 2.008x Lecture Slides)A. John Hart
Slides accompanying 2.008x* video module on Sheet Metal Forming, Prof. David Hardt, MIT, 2016.
*Fundamentals of Manufacturing Processes on edX: https://www.edx.org/course/fundamentals-manufacturing-processes-mitx-2-008x
IRJET- Experimental Investigation of AISI 1015 Steel Plate in Milling by Resp...IRJET Journal
This document presents an experimental investigation into milling of AISI 1015 steel plate using response surface methodology. Experiments were conducted varying cutting speed, feed rate, and depth of cut. Response surface regression models were developed to predict surface roughness and material removal rate based on the cutting parameters. The models were found to explain over 94% of the variation in surface roughness and over 96% of the variation in material removal rate. Various tests confirmed that the models were statistically valid and adequately represented the relationships between the cutting parameters and responses.
This document summarizes key aspects of thermo compression bonding (TCB) technology from the perspective of a machine vendor. It discusses three core TCB capabilities that are essential for high yield: accuracy, co-planarity, and sophisticated bond control. Maintaining high accuracy during temperature ramping from cold to hot states is critical. Co-planarity must also be maintained during temperature ramping to avoid yield issues. Sophisticated hybrid bond control, as used in the TC-CUF process, tightly controls bond line thickness despite thermal expansion movements.
The document describes a study on the mechanical properties of friction stir processed AA5754 sheet metal at different temperatures and strain rates. The objectives were to characterize the tensile properties of FSPed and base metal sheets under various conditions and develop a Johnson Cook model to predict flow stress. Tensile tests were conducted on FSPed and base metal specimens at temperatures from room temperature to 400°C and crosshead velocities from 1-200mm/min. The results showed that both yield strength and ultimate tensile strength generally decreased with increasing temperature and strain rate for both materials. The FSPed material exhibited higher ductility than the base metal across most test conditions.
Slides accompanying 2.008x* video module on Casting, Prof. John Hart, MIT, 2016.
*Fundamentals of Manufacturing Processes on edX: https://www.edx.org/course/fundamentals-manufacturing-processes-mitx-2-008x
Thermoforming (MIT 2.008x Lecture Slides)A. John Hart
Slides accompanying 2.008x* video module on Thermoforming, Prof. John Hart, MIT, 2016.
*Fundamentals of Manufacturing Processes on edX: https://www.edx.org/course/fundamentals-manufacturing-processes-mitx-2-008x
Variation and Quality (2.008x Lecture Slides)A. John Hart
Slides accompanying 2.008x* video module on Variation and Quality, Prof. John Hart, MIT, 2016.
*Fundamentals of Manufacturing Processes on edX: https://www.edx.org/course/fundamentals-manufacturing-processes-mitx-2-008x
This document summarizes the work progress of a group project on welding and characterization of Ti-5Al-2.5Sn alloy. The group members are Umer Shahab, Talha Nasir Khan Lodhi, and Mian Muhammad Hussain, advised by Dr. Fahd Nawaz and co-advised by Dr. Imran Khan. The document outlines that wire EDM, electron beam welding, tensile testing, impact testing, microscopy, and residual stress testing via the hole-drill method were performed on the alloy. Key results mentioned include the tensile and impact test data, microstructural images showing the fusion zone, heat affected zone and base metal, and that residual stress distribution
The document summarizes research on structurally retrofitting reinforced concrete circular columns using carbon fiber reinforced polymer (CFRP). Finite element modeling was used to simulate column tests and compare results to design guidelines. The modeling captured material behavior accurately. Guidelines could be improved by better defining key parameters like confining pressure. Further research is needed on inclined wrapping schedules and other factors' effects.
The document provides information on various aspects of spot welding including:
- Definitions of key terms like spot weld, welding control, and the importance of force between electrodes.
- Explanations of spot welding principles involving resistance heating when current passes through interfaces of stacked metals joined by electrodes applying pressure.
- Advantages of spot welding as the quickest and most economical method for joining metals requiring no filler medium.
- Details on TPM system pillars like autonomous maintenance, planned maintenance, quality maintenance, and focused improvement to maintain production quality and equipment lifespan.
"Here Is Streaming http://www.watchtheboxing.net/ Mayweather vs Berto will be taking place on September 12 at MGM Grand Arena through the http://www.watchtheboxing.net/ In the main event, Mayweather and Berto will have to make the welterweight limit of 147 pounds.
Watch Live Stream On Android,Mac Ios,Tab,Windows Phones Or Other Digital Devices
The Mayweather vs. Pacquiao weigh-in takes place at 6 p.m. ET at the MGM Grand in Las Vegas, Nev., and the video is above."
El documento presenta los resultados de una encuesta realizada a 109 estudiantes de secundaria sobre su uso de las redes sociales. La mayoría de los estudiantes usan redes sociales como WhatsApp e Instagram a diario y tienen entre 100 y 600 contactos, aunque no todos los conocen. Algunos estudiantes publican información personal como fotos y detalles sobre su familia sin darse cuenta de los posibles riesgos. La encuesta revela la necesidad de enseñar a los estudiantes a usar las redes sociales de forma segura y responsable.
We have reason to believe that the SEC already has Qihoo on its radar. Given the information presented in this report, along with other issues that we have omitted, we believe that Qihoo will be delisted from the NYSE and management charged with securities fraud.
Solutions Overview for Public TransportWestbase.io
Public transport organisations are rapidly expanding their on-the-road technology in order to deliver improved efficiencies and to expand customer service capabilities. From passenger WiFi, to improved scheduling notifications, connectivity is a key enabler of this. Offering simple installation and integration with existing network infrastructure, 3G/4G solutions can deliver superfast, reliable and secure connectivity anywhere – a perfect solution for mobile applications.
This document outlines a learning path for data driven marketing. It was created on January 24, 2017 by Sydney Platt and focuses on providing guidance for using data to inform marketing strategies and decisions. The learning path likely includes topics such as data analytics, customer insights, marketing automation, and measurement to help marketers leverage data to improve outcomes.
Las enfermedades de transmisión alimentaria constituyen un problema de salud pública creciente a nivel mundial. Las mismas se deben a la ingestión de agua o alimentos contaminados.
Carl Sandburg was an American poet and writer who won three Pulitzer Prizes. One of his most famous poems is "Fog", which is only six lines long. The poem compares a fog rolling into a city and harbor to a kitten, describing how it comes in silently and sits looking over the landscape in the way a cat might. It sits silently on its haunches before moving on, mirroring how cats and fog are both transient presences that do not remain in one place for long.
The document summarizes research on evaluating the low-cycle fatigue durability of shear panel dampers (SPDs) used in bridges. Finite element analysis was used to investigate the influence of SPD dimensional parameters on crack initiation life and critical crack length. The analysis considered factors like weld toe radius, aspect ratio, and width-to-thickness ratio. Regression analysis was used to determine a relationship between critical crack length and these parameters. The research aims to also evaluate crack propagation life using the J-integral approach to calculate crack growth per cycle and determine the number of cycles until failure.
Optimization of Weld Bead Geometry in Submerged Arc Welds Deposited On En24 S...iosrjce
IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) is a double blind peer reviewed International Journal that provides rapid publication (within a month) of articles in all areas of mechanical and civil engineering and its applications. The journal welcomes publications of high quality papers on theoretical developments and practical applications in mechanical and civil engineering. Original research papers, state-of-the-art reviews, and high quality technical notes are invited for publications.
This document summarizes an experiment that used the Taguchi method to optimize weld bead geometry for submerged arc welds deposited on EN24 steel alloy. The experiment varied three process parameters - voltage, current, and travel speed - at three levels each using an L9 orthogonal array. Weld penetration shape factor was evaluated as the output parameter. Analysis found that voltage had the greatest influence on penetration and was the most significant factor. Optimal parameters for maximum penetration were a voltage of 30V, current of 300A, and speed of 30m/hr. Analysis of variance confirmed that voltage made the most significant contribution to the weld penetration shape factor.
This document summarizes an experiment that used the Taguchi method to optimize weld bead geometry in submerged arc welds on EN24 steel alloy. The researchers conducted experiments using an orthogonal array to test different combinations of welding voltage, current, and travel speed. Analysis of variance showed that voltage had the greatest influence on weld penetration shape factor. The optimal parameters found were a voltage of 30V, current of 300A, and speed of 30m/hr, which produced the maximum penetration. In conclusion, voltage was identified as the most significant factor controlling weld bead geometry according to this experiment.
IRJET- Experimental Study of Double Skinnd Concrete Filled Steeltubular S...IRJET Journal
1) The document reports on an experimental study of double skin concrete filled steel tubular structures under bending.
2) Various double skin concrete filled steel tubular beam specimens with varying inner and outer tube dimensions and thicknesses were tested.
3) The bending test results showed that the beams performed well in flexure and had greater strength than comparable single-skin concrete filled steel tubes, due to composite action between the steel and concrete.
Research Inventy : International Journal of Engineering and Scienceinventy
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.
Optimization of EDM process parameters for machining SS310IRJET Journal
This document discusses optimizing process parameters in electrical discharge machining (EDM) of stainless steel SS310. A study was conducted using Taguchi's design of experiments to optimize discharge current and spark gap to increase material removal rate and decrease tool wear rate. Experiments were performed with copper as the tool material and SS310 as the workpiece. The results found that discharge current had the greatest influence on both material removal rate and tool wear rate, with higher currents increasing material removal rate and tool wear rate. The optimal parameters were determined to be a higher discharge current to maximize material removal rate.
33 residual stress simulation and experimental stress replication of mock up ...leann_mays
This document discusses simulations and experiments related to residual stress and stress corrosion cracking in welded mock-ups. It summarizes residual stress simulations of circumferential and longitudinal welds using finite element analysis and compares results to experimental measurements. It also describes the design of four-point bend experiments using finite element simulations to replicate stress conditions and digital image correlation experiments to validate simulations. The purpose is to model stress corrosion cracking using multiphysics finite element analysis.
Parametric Study of Multi-Spot Welded Lap Shear Specimen for Shear StrengthIJERA Editor
The effect of number of spots, spot spacing, squeezing force, welding current, weld time , overlapping length
and sheet thicknesson the shear strength of two similar galvanized steel sheets are investigated through
experiments using RSM method. Similar sheets of galvanized steel sheets are made by resistance spot welding
at different processing conditions and these joint populations were tested under lap-shear loading conditions.
Specially fabricated fixture is used to load the lap shear specimen in the universal testing machine Regression
analysis is done to obtain relationship between shear strength and selected parameters. The experimental results
indicate that the failure loads of spot welds in lap-shear specimens increase when number of spot, squeezing
force, welding current and sheet thickness increase for the given ranges.
The document outlines an experimental plan to optimize friction stir welding parameters for joining AA6061 and AA7075 aluminum alloys. Key points:
- The study will weld AA6061 and AA7075 plates using different tool rotation speeds, welding speeds, tilt angles, and surface roughnesses.
- Samples will be tested for ultimate tensile strength, elongation, hardness, and microstructure. Regression and Taguchi-Grey analysis will be used to optimize parameters.
- The goal is to develop models to predict mechanical properties and optimize parameters to maximize strength of the welded joints. Confirmatory tests will then validate the optimized parameters.
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Similar to Nondestructive Approach to Evaluate Defects in Elements of Agricultural Machinery (20)
2. Md. Nur-A-Alam
B. Sc. in Agril. Engg., MS in FPM, PGD-in-ICT
Bangladesh Agricultural University,
Mymensingh-2202
Presented ByPresented By
Slide 2 / 33
3. IntroductionIntroduction
▓ Farm machineries are major elements of farm
mechanization in Bangladesh
▓ Timeliness in farm operations is a crucial factor
for successful agricultural operations
▓ The failure of important parts like PTO/propeller
shaft, spline shaft, tine/blade etc. of farm
machineries especially tractor and power tiller
during the peak season causes various large
losses of revenue and inefficient utilization of
labor
Slide 3 / 33
5. IntroductionIntroduction (Contd.)(Contd.)
▓ Therefore, it is necessary to routine check-up,
inspection and diagnose of important parts of
agricultural machinery for getting proper
performance and timeliness operation
▓ lt is possible to adjust, repair and/or replace the
defective component/parts according to diagnose
results
Slide 5 / 33
6. JustificationJustification
▓ Non-destructive testing is a key inspection
criterion - across many fields of engineering
▓ ln agricultural machinery sector to maximize
efficiency, minimize downtime and improve
productivity
- reliable and accurate nondestructive
testing
- integrity assessment are essential
Slide 6 / 33
7. JustificationJustification (Contd.)(Contd.)
▓ There is no available technique/method
to nondestructively evaluate/diagnose the
important parts of agricultural
machinery in Bangladesh
▓ The four-point probe potential drop (PD)
technique can be considered one of the
best candidates for the purpose
Slide 7 / 33
8. ObjectivesObjectives
▓ To develop a laboratory based nondestructive
testing set up for evaluating of internal
defects/cracks in the important parts of
agricultural machinery
The specific objectives are:
i) To design and develop of a DC four-
point probe measuring system
ii) To detect internal cracks and defects of
machine parts nondestructively
Slide 8 / 33
9. Objective-Methods Link
Objective Methods
1) To design and develop of a DC
four-point probe measuring
system
Literature and document review
Design and construction of probe
Experimental set up
2) To detect internal cracks and
defects of machine parts
nondestructively
Analyzing the data collected through
experiment
Examine the defective material from
different sides to detect crack
Development of a computer program
using a mathematical equation
related with voltage, resistivity and
input current
Materials and MethodsMaterials and Methods
Slide 9 / 33
10. Materials Used in the Potential Drop Measurement System
Materials and MethodsMaterials and Methods
(Contd.)(Contd.)
Materials Specification/Capacity
Power Suppliers A Battery of 12 V
Ammeter Sfim Panel Meter; Model: SF-80, Range: AC/DC 50A
Multimeter Fluke 28 II True RMS Multimeter
Rheostat A variable rheostat having capacity of 25 Ampere
Electric wire 3-22, 1 core-10 yards
Insulating Materials Plastic fibre
Probe SS rod having diameter of (4 pcs)
Spring Having a diameter of (4 pcs)
Nut Having diameter of used on the fiber (4 pcs) and
having diameter of used on the thread of probe (4 pcs)
Bolt Use to keep probe set rigidly on sample (2 pcs)
Frame Wooden frame
Code::Blocks 12.11 To make a calculator according to above formula using C++
programming language to determine voltage drop
Slide 10 / 33
inch
8
1
inch
8
3
inch
8
5
inch
8
1
12. Materials and MethodsMaterials and Methods
(Contd.)(Contd.)
Slide 12 / 33
Assembly Drawing of the Probe
2D View of the Probe
13. Testing Materials
MS Flat Bar
SS Flat Bar
CS Flat Bar
ProbeProbe
Materials and MethodsMaterials and Methods
(Contd.)(Contd.)
Slide 13 / 33
Experimental Set up with DC CurrentExperimental Set up with DC Current
14. Materials and MethodsMaterials and Methods
(Contd.)(Contd.)
Voltage Drop Calculation
V=IR (From Ohm’s Law)
Where,
∆Φ = Voltage Drop
ρ = Resistivity of Metal
I = Current
π = Constant
S1 = Half Distance of Current Probes
S2 =Half Distance of Voltage Probes
2
2
2
1
1
S-S
S
×
π
I2
=ΔΦ
ρ
Slide 14 / 33
Circuit Diagram
15. (a) (b)
Schematic Diagram of Crack free Sample Schematic Diagram of Single Cracked Sample
Crack free Sample Single Cracked Sample Twisted Sample
Crack Type
Single Crack
Twisted
Materials and MethodsMaterials and Methods
(Contd.)(Contd.)
Experimental Design for Mild Steel Flat Bar
Dimension: 18 cm×2.5 cm×4 mm
Spacing: S1 = 15.25 cm and S2 = 2.5 cm
S1 = 12. 50 cm and S2 = 2.5 cm
S1 = 17.75 cm and S2 = 5 cm
S1 = 15.25 cm and S2 = 5 cm
Slide 15 / 33
16. Schematic Diagram of Crack free Sample Schematic Diagram of Cracked Sample
Crack Free Sample Single Cracked Sample
Experimental Design for Stainless Steel Flat Bar
Materials and MethodsMaterials and Methods
(Contd.)(Contd.)
Dimension: 18 cm×3.75 cm×4 mm
Spacing: S1 = 15.25 cm and S2 = 2.5 cm
S1 = 12. 50 cm and S2 = 2.5 cm
S1 = 17.75 cm and S2 = 5 cm
S1 = 15.25 cm and S2 = 5 cm
Crack Depth
1 mm
2 mm
3 mm
Slide 16 / 33
17. Schematic Diagram of Crack free Sample Schematic Diagram of Cracked Sample
Crack Free Sample Single Cracked Sample
Experimental Design for Carbon Steel Flat Bar
Materials and MethodsMaterials and Methods
(Contd.)(Contd.)
Dimension: 18 cm×2.5 cm×6 mm
Spacing: S1=15.25 cm and S2=2.5 cm
S1=12. 50 cm and S2=2.5 cm
S1=17.75 cm and S2=5 cm
S1=15.25 cm and S2=5 cm
Crack Depth
1 mm
2 mm
3 mm
Slide 17 / 33
22. Experimental Result of Stainless Steel Flat Bar
Comparison of Voltage Drop on different conditions of SS Flat Bar
ResultsResults (Contd.)(Contd.)
Slide 22 / 33
23. Experimental Result of Stainless Steel Flat Bar
Effect of Probe Spacing on Voltage Drop for Different Conditions of SS Flat Bar
ResultsResults (Contd.)(Contd.)
Slide 23 / 33
24. Experimental Result of Stainless Steel Flat Bar
Resistivity for SS Flat Bar in Crack free Condition
ResultsResults (Contd.)(Contd.)
Slide 24 / 33
Current
(A)
Spacing
Resistivity, ρ
(Ω-m)
Sub-Average
Resistivity, ρ (Ω-
m)
Average Resistivity,
ρ (Ω-m)S1 (cm) S2 (cm)
5
15.25 2.5 5.11×10-4
5.0025×10-4
3.915×10-
4
12.5 2.5 3.58×10-4
17.75 5 5.83×10-4
15.25 5 4.95×10-4
10
15.25 2.5 3.55×10-4
3.455×10-412.5 2.5 2.54×10-4
17.75 5 4.28 ×10-4
15.25 5 3.45×10-4
15
15.25 2.5 3.41×10-4
3.2875×10-412.5 2.5 2.57×10-4
17.75 5 4.00×10-4
25. Experimental Result of Stainless Steel Flat Bar
Resistivity in Different Current on SS Flat Bar
ResultsResults (Contd.)(Contd.)
Slide 25 / 33
26. Experimental Result of Carbon Steel Flat Bar
Comparison of Voltage Drop on different conditions of CS Flat Bar
ResultsResults (Contd.)(Contd.)
Slide 26 / 33
30. DiscussionDiscussion
Slide 30 / 33
The voltage drop increases with the increasing resistance in
current flow path
The resistivity of the materials differs slightly for same condition
The resistivity depends on the material composition and
properties
Both Mathematically and Experimentally
∆Φ of 15.25 cm and 2.5 cm spacing < ∆Φ of 12.50 cm and 2.5 cm
spacing
∆Φ of 17.75 cm and 5 cm spacing < ∆Φ of 15.25 cm and 5 cm spacing
31. DiscussionDiscussion (Contd.)(Contd.)
Slide 31 / 33
Two calculation procedure developed using code::blocks
12.11 (C++ programming language)
GUI for Resistivity MeasurementGUI for Voltage Drop Calculation
32. ConclusionsConclusions
Slide 32 / 33
A low-current experimental setup for Voltage Drop
measurements was developed
Variation of voltage drop on the same sample before
and after cracking indicates the presence of defects
The evaluation is made by a simple, non-iterative
formula
The developed technique is capable to detect any
inhomogeneity (defects) and to determine resistivity
A simple computer based calculator was made to
find out the resistivity and voltage drop according to
the formula