The document describes an experiment to determine and compare the material properties of two specimens under quasi-static and dynamic loading. Students used an Instron testing machine to obtain data for quasi-static loading, which was provided. For dynamic loading, students used a Split-Hopkinson pressure bar to induce a strain wave and collected data via oscilloscope. Equations were used to calculate properties like stress, strain, modulus from the experimental data. Results showed that both specimens exhibited higher modulus and yield strength under dynamic loading compared to quasi-static loading.
This document summarizes a lab where students used an Instron Universal Testing Machine to perform tensile and compressive tests on various materials to generate stress-strain plots and determine material properties. Students tested an unknown metal, carbon fiber, nylon, and plaster of paris. They identified the unknown metal as grade 340 X steel based on its mechanical properties. Analysis of the stress-strain plots and material properties showed carbon fiber has the highest specific strength and stiffness. The document outlines the procedures, results, and conclusions from the material testing and analysis.
Students used a charpy impact tester to collect data on testing brass and marble specimens. They analyzed the data to calculate the absorbed impact energy, work done during impact, and elastic and plastic portions of energy absorption. Brass absorbed more energy and required more work to fracture, showing it is the stronger material. The rate at which a force is applied affects material properties, and dynamic loading is different than static loading since the applied force is not constant during impact.
In this lab, students tested the shear strength of two adhesives - cyanoacrylate and epoxy - using a testing machine. The maximum shear stress of each adhesive was calculated from the test data. Confidence intervals were also constructed for the shear stress results. The lab values were smaller than literature values, likely due to differences in specimen preparation between a student lab and professional testing. Epoxy was found to have a higher shear strength than cyanoacrylate based on the results.
The document describes a lab experiment to construct a cantilever beam with an attached strain gage. This setup is used to determine the weights of various objects by measuring changes in resistance from the strain gage. The beam is calibrated using two methods: 1) pure bending theory based on mechanics principles and 2) a calibration curve method using known weights. Results show the calibration curve method has lower uncertainty and is therefore more accurate for determining unknown weights.
This document describes the design of a steel staircase with 12 steps to provide access between two floors of a household. Key details include:
- The design concept uses 12 steel steps connected by brackets to a central 6" diameter pole.
- Analysis shows the welds and fasteners will withstand the intended 300 lb load capacity with safety factors above 1.
- Features include pre-welded construction for easy assembly using bolts, and durable all-steel design.
This project involves analyzing a plane truss structure using finite element analysis to determine stresses and displacements under different loading conditions. The truss is modeled and analyzed for three loading cases. Equivalent beam properties are then determined for the truss. Finally, the analysis is repeated after extending the truss by two additional bays to observe how the properties change with the increased size.
1. The document describes an experiment to determine the reactions at supports of a continuous beam subjected to point loads and uniformly distributed loads. Reactions are measured using load cells and compared to theoretical calculations.
2. For a beam with a point load, measured reactions were within 12% of calculations. For a beam with uniform loading, measured reactions matched calculations within 4% except at one support where they matched exactly.
3. Differences between measured and calculated reactions are likely due to imperfections in the old laboratory apparatus and effects of airflow on measurements. The experiment successfully validated the theoretical reactions within an acceptable margin of error.
This is my Lab Report of Tensile Test when I was conducting engineering material lab in Sampoerna University. Feel free to download for a reference.
I know it is not a good report, but I hope this share might help you to find something you need.
Thank you.
This document summarizes a lab where students used an Instron Universal Testing Machine to perform tensile and compressive tests on various materials to generate stress-strain plots and determine material properties. Students tested an unknown metal, carbon fiber, nylon, and plaster of paris. They identified the unknown metal as grade 340 X steel based on its mechanical properties. Analysis of the stress-strain plots and material properties showed carbon fiber has the highest specific strength and stiffness. The document outlines the procedures, results, and conclusions from the material testing and analysis.
Students used a charpy impact tester to collect data on testing brass and marble specimens. They analyzed the data to calculate the absorbed impact energy, work done during impact, and elastic and plastic portions of energy absorption. Brass absorbed more energy and required more work to fracture, showing it is the stronger material. The rate at which a force is applied affects material properties, and dynamic loading is different than static loading since the applied force is not constant during impact.
In this lab, students tested the shear strength of two adhesives - cyanoacrylate and epoxy - using a testing machine. The maximum shear stress of each adhesive was calculated from the test data. Confidence intervals were also constructed for the shear stress results. The lab values were smaller than literature values, likely due to differences in specimen preparation between a student lab and professional testing. Epoxy was found to have a higher shear strength than cyanoacrylate based on the results.
The document describes a lab experiment to construct a cantilever beam with an attached strain gage. This setup is used to determine the weights of various objects by measuring changes in resistance from the strain gage. The beam is calibrated using two methods: 1) pure bending theory based on mechanics principles and 2) a calibration curve method using known weights. Results show the calibration curve method has lower uncertainty and is therefore more accurate for determining unknown weights.
This document describes the design of a steel staircase with 12 steps to provide access between two floors of a household. Key details include:
- The design concept uses 12 steel steps connected by brackets to a central 6" diameter pole.
- Analysis shows the welds and fasteners will withstand the intended 300 lb load capacity with safety factors above 1.
- Features include pre-welded construction for easy assembly using bolts, and durable all-steel design.
This project involves analyzing a plane truss structure using finite element analysis to determine stresses and displacements under different loading conditions. The truss is modeled and analyzed for three loading cases. Equivalent beam properties are then determined for the truss. Finally, the analysis is repeated after extending the truss by two additional bays to observe how the properties change with the increased size.
1. The document describes an experiment to determine the reactions at supports of a continuous beam subjected to point loads and uniformly distributed loads. Reactions are measured using load cells and compared to theoretical calculations.
2. For a beam with a point load, measured reactions were within 12% of calculations. For a beam with uniform loading, measured reactions matched calculations within 4% except at one support where they matched exactly.
3. Differences between measured and calculated reactions are likely due to imperfections in the old laboratory apparatus and effects of airflow on measurements. The experiment successfully validated the theoretical reactions within an acceptable margin of error.
This is my Lab Report of Tensile Test when I was conducting engineering material lab in Sampoerna University. Feel free to download for a reference.
I know it is not a good report, but I hope this share might help you to find something you need.
Thank you.
This document provides an overview of tensile testing. It discusses tensile specimens, testing machines, stress-strain curves, and key mechanical properties measured by tensile tests such as strength, ductility, and elastic modulus. Tensile tests are used to select materials, ensure quality, compare new materials/processes, and predict behavior under other loads. Stress-strain curves are generated by applying tension to a specimen and recording the resulting force and elongation. Important aspects of the curves, like yield strength and plastic deformation, are defined.
This document provides instructions for conducting a tensile test to determine the mechanical properties of polymers. A tensile test involves gripping a dogbone-shaped polymer specimen at both ends and pulling it at a constant rate until failure. Key points:
- Stress-strain curves are generated from the test, showing properties like elastic modulus, yield point, and toughness.
- Properties depend on factors like crystallinity, molecular weight, and glass transition temperature. Brittle polymers have steeper stress-strain curves.
- The test procedure involves preparing specimens to standards, setting up the tensile testing machine and software to control displacement rate and record data, calibrating load cells, gripping the specimen, and conducting the
ENGINEERING SYSTEM DYNAMICS-TAKE HOME ASSIGNMENT 2018musadoto
1. Read Chapter 4 – System Dynamics for Mechanical Engineers by Matthew Davies and Tony L. Schmitz and implement Examples 4.1 to 4.12 in Matlab.
2. Read Chapter 7 – System Dynamics for Mechanical Engineers by Matthew Davies and Tony L. Schmitz and implement Examples 7.1 to 7.11 in Matlab.
3. Read Chapter 9 – System Dynamics for Mechanical Engineers by Matthew Davies and Tony L. Schmitz and implement Examples 9.1 to 9.6 in Matlab.
4. Read Chapter 11 – System Dynamics for Mechanical Engineers by Matthew Davies and Tony L. Schmitz and implement Examples 11.1 to 11.7 in Matlab.
5. Read Chapter 2 - System Dynamics for Engineering Students: Concepts and Applications by Nicolae Lobontiu and attempt problem 2.18 (page 63).
6. Read Chapter 3 - System Dynamics for Engineering Students: Concepts and Applications by Nicolae Lobontiu and attempt problem 3.13 (pp 98 - 100).
7. Read Chapter 4 - System Dynamics for Engineering Students: Concepts and Applications by Nicolae Lobontiu and attempt problem 4.20 (page 146).
8. Read Chapter 5 - System Dynamics for Engineering Students: Concepts and Applications by Nicolae Lobontiu and attempt problems 5.15 (page 198), 5.21 (pp 199 - 200) and 5.27 (pp 201 – 202).
Objective of the experiment:
1 - Study the relationship between the force (P) and
elongation (ΔL).
2 - Stability and study the relationship between strain (ε)
and stress (σ).
3 - Study the concept of the mechanical properties of solids.
4 - Establish a modulus of elasticity (E)
Group presentation for tensile testing a4Prajwal Vc
The document describes the methodology, instrumentation, and results of tensile testing experiments on various metal samples. The methodology involved determining sample dimensions, marking intervals on the samples, setting up the tensile testing equipment which includes an extensometer and Hounsfield testing machine, applying and increasing load while recording extension and results. Graphs of stress-strain responses were produced for aluminum, brass, and mild steel samples, showing their different mechanical behaviors under tensile loading. Key properties of each metal were also discussed.
The document describes an experimental investigation of a rope belt friction apparatus. The experiment measured the ratio of belt tensions (T1/T2) over varying lap angles from 30° to 180° with a constant load T1. It was found that the ratio of tensions gradually decreased as the lap angle increased from 30° to 180°. Additional experiments examined how changing both the lap and groove angles affected the tension ratio, finding that the ratio increased with variations in these angles. From the experiments, the coefficient of friction for the rope on the pulley surface was calculated to be 0.53.
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
This study compares experimental and finite element analysis results for stress analysis. Strain gauges were placed on test materials (a beam and contacting blocks) at locations corresponding to finite element mesh nodes. Testing involved applying loads and measuring strain. Results showed good agreement between experimental and numerical analyses for the linear beam problem. For the nonlinear contacting blocks problem, close placement of strain gauges was important due to high stress gradients at contact points. Small gauge placement errors could cause up to 10% difference in strain measurements. The approach demonstrated that matching strain gauge locations to finite element meshes facilitated accurate validation of numerical models.
The document discusses tensile testing procedures and principles. It outlines the components of a universal testing machine used for tensile testing, including the load frame, load cell, crosshead, and output devices. It then provides details on conducting a tensile test, including specimen preparation, loading procedure, and data collection. Examples are given demonstrating how load and elongation data can be used to determine material properties and how finite element analysis can simulate the effects of strain hardening.
This document summarizes research on evaluating the shear strength of the char layer formed on thermoplastic polyurethane elastomer nanocomposites (TPUNs) used as ablative materials. TPUN samples reinforced with carbon nanofibers and carbon nanotubes were tested using an oxy-acetylene test bed to simulate the extreme heating of a solid rocket motor. Infrared cameras and sensors monitored the sample surface temperature and behavior during testing. A shear strength sensor was used to apply a transverse load to the charred samples until rupture, measuring the reaction force. The maximum force and energy required to fracture the samples were evaluated to determine which material's char layer had the best shear strength performance for insulation applications
This experiment tested the tensile properties of steel, aluminum, and two polymeric materials. Specimens of each material were pulled apart in a tensile testing machine at a constant strain rate to measure properties like yield strength, tensile strength, and elongation. The engineering stress-strain and true stress-strain curves were plotted and compared for each material. Values for properties like Young's modulus, yield stress, and tensile strength were determined from the curves and compared to literature values. Sources of experimental error were also discussed.
The document describes three experiments measuring strain on different surfaces using strain gauges:
1) Measuring strain on an I-beam under varying loads, finding theoretical strain values match measured values. Principal strains are calculated.
2) Measuring strain on a torsional cylindrical rod, calculating principal strains.
3) Measuring combined bending and torsion strain on a circular shaft, calculating principal strains using Mohr's circle.
The experiments aim to observe and compare measured and theoretical strain values using strain gauges and analytical calculations.
This document provides details on the structure and content for a 10-page tensile test report analyzing collected data from destructive tensile testing of an aluminum sample. The report will include sections defining and calculating mechanical properties like proportional limit stress, yield point stress, ultimate tensile stress, breaking stress, modulus of elasticity, modulus of resilience, and modulus of toughness. Graphs and calculations of these properties will be presented along with pages for statistical process control data and summary calculations.
This report summarizes a shock test experiment on a cantilevered aluminum beam. A rotating hammer struck the beam at various angles, and a string gauge measured the resulting deformation. The maximum impact strain of 1876 μ-strain occurred at 20 degrees. Calculations determined the maximum stress on the beam was 18760.69 psi, which is 40.43% of the yield stress for aluminum. The energy loss in the system was approximately 28.5%, and the natural frequency of the beam was 76.92 Hz. The experiment verified relationships between impact energy, beam deformation, and impact angle.
This document provides an overview of key concepts in physics related to motion, including:
- Definitions of terms like speed, velocity, acceleration, displacement, and distance.
- Equations for calculating average speed, velocity, acceleration, and distance traveled with constant acceleration.
- The relationship between time and velocity/distance for objects experiencing constant acceleration due to gravity.
- Centripetal acceleration and the equation relating centripetal acceleration, velocity, and radius of circular motion.
Three samples of 7075 aluminum with intentional defects (a center hole, U-notches, and V-notches) were tested under tension to determine their stress concentration characteristics (K) compared to a reference sample. Theoretical calculations of K matched experimental results, with the hole sample having the lowest K of 2.25 and the U-notch and V-notch samples having similar higher K values of 2.60 and 2.58, respectively. Stress-strain curves were produced for each sample and showed how stress accumulates more at defect points, with the maximum stress given by the product of K and the nominal stress.
Strength of material lab, Exp 2: Tensile test Osaid Qasim
by using our “UTM” machine that
operates on the basis of applying a load in our specimen , so if
we take this force and compare it with change in the length of
specimen “Deformation” we can obtain a (Load-Deformation
diagram) , and by applying this force and divide it by the
specimen cross sectional area we get the Stress ( σ), and divide
the “Deformation” by the original length of the specimen we
will get the Strain (ϵ) , and comparing the stress with strain
results a very Important curve that is characteristic of the
properties of the material and it’s the (Stress-Strain Diagram),
The experiment involves tensile testing of materials using an Instron load frame and BlueHill data acquisition software. Four materials - 6061-T6 aluminum alloy, A-36 hot rolled steel, PMMA, and polycarbonate - were tested with cylindrical specimens containing a reduced gage section. Testing was conducted according to ASTM standards. The data gathered was used to calculate properties like elastic modulus, yield strength, and ultimate tensile strength, which were plotted on stress-strain curves. The purpose was to determine key mechanical properties of each material and familiarize students with tensile testing procedures.
Tensile testing is used to determine the strength and ductility of materials. A specimen is placed in grips and pulled apart under increasing tensile force while measuring elongation. The resulting stress-strain curve provides properties like yield strength, tensile strength, and Young's modulus. Tensile tests are important for engineering design and quality control by ensuring materials can withstand expected loads and comparing new materials. Common applications include testing aircraft components, bolts, and other loaded structures.
- Victor M. Baltazar has over 15 years of experience in quality control engineering and mechatronics. He has a background in quality systems and standards like PPAP, FAIR, APQP, and CP.
- He is bilingual in English and Spanish with expertise in areas such as electrical and mechanical equipment, Microsoft Office, and CAD/CAM software.
- Baltazar held various roles at companies like Gecko Alliance, Micro Precision Calibration Mexico, and SMK Electrónica where he performed tasks like quality inspection, process validation, documentation creation, and equipment calibration.
- Girls often do not choose science careers due to negative stereotypes of scientists in media, a view of science as abstract and irrelevant, and a lack of confidence in math and science abilities.
- Effective science outreach aims to change these subtle attitudes by projecting a positive image of science, emphasizing its social relevance, and showing that success requires practice, not innate ability.
- Presenters should discuss their normal lives, interests in science as a hobby, and diverse people in science to make it seem appealing. They should also stress that math requires practice, not genius, and promote extracurricular clubs to support practice.
This document provides an overview of tensile testing. It discusses tensile specimens, testing machines, stress-strain curves, and key mechanical properties measured by tensile tests such as strength, ductility, and elastic modulus. Tensile tests are used to select materials, ensure quality, compare new materials/processes, and predict behavior under other loads. Stress-strain curves are generated by applying tension to a specimen and recording the resulting force and elongation. Important aspects of the curves, like yield strength and plastic deformation, are defined.
This document provides instructions for conducting a tensile test to determine the mechanical properties of polymers. A tensile test involves gripping a dogbone-shaped polymer specimen at both ends and pulling it at a constant rate until failure. Key points:
- Stress-strain curves are generated from the test, showing properties like elastic modulus, yield point, and toughness.
- Properties depend on factors like crystallinity, molecular weight, and glass transition temperature. Brittle polymers have steeper stress-strain curves.
- The test procedure involves preparing specimens to standards, setting up the tensile testing machine and software to control displacement rate and record data, calibrating load cells, gripping the specimen, and conducting the
ENGINEERING SYSTEM DYNAMICS-TAKE HOME ASSIGNMENT 2018musadoto
1. Read Chapter 4 – System Dynamics for Mechanical Engineers by Matthew Davies and Tony L. Schmitz and implement Examples 4.1 to 4.12 in Matlab.
2. Read Chapter 7 – System Dynamics for Mechanical Engineers by Matthew Davies and Tony L. Schmitz and implement Examples 7.1 to 7.11 in Matlab.
3. Read Chapter 9 – System Dynamics for Mechanical Engineers by Matthew Davies and Tony L. Schmitz and implement Examples 9.1 to 9.6 in Matlab.
4. Read Chapter 11 – System Dynamics for Mechanical Engineers by Matthew Davies and Tony L. Schmitz and implement Examples 11.1 to 11.7 in Matlab.
5. Read Chapter 2 - System Dynamics for Engineering Students: Concepts and Applications by Nicolae Lobontiu and attempt problem 2.18 (page 63).
6. Read Chapter 3 - System Dynamics for Engineering Students: Concepts and Applications by Nicolae Lobontiu and attempt problem 3.13 (pp 98 - 100).
7. Read Chapter 4 - System Dynamics for Engineering Students: Concepts and Applications by Nicolae Lobontiu and attempt problem 4.20 (page 146).
8. Read Chapter 5 - System Dynamics for Engineering Students: Concepts and Applications by Nicolae Lobontiu and attempt problems 5.15 (page 198), 5.21 (pp 199 - 200) and 5.27 (pp 201 – 202).
Objective of the experiment:
1 - Study the relationship between the force (P) and
elongation (ΔL).
2 - Stability and study the relationship between strain (ε)
and stress (σ).
3 - Study the concept of the mechanical properties of solids.
4 - Establish a modulus of elasticity (E)
Group presentation for tensile testing a4Prajwal Vc
The document describes the methodology, instrumentation, and results of tensile testing experiments on various metal samples. The methodology involved determining sample dimensions, marking intervals on the samples, setting up the tensile testing equipment which includes an extensometer and Hounsfield testing machine, applying and increasing load while recording extension and results. Graphs of stress-strain responses were produced for aluminum, brass, and mild steel samples, showing their different mechanical behaviors under tensile loading. Key properties of each metal were also discussed.
The document describes an experimental investigation of a rope belt friction apparatus. The experiment measured the ratio of belt tensions (T1/T2) over varying lap angles from 30° to 180° with a constant load T1. It was found that the ratio of tensions gradually decreased as the lap angle increased from 30° to 180°. Additional experiments examined how changing both the lap and groove angles affected the tension ratio, finding that the ratio increased with variations in these angles. From the experiments, the coefficient of friction for the rope on the pulley surface was calculated to be 0.53.
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
This study compares experimental and finite element analysis results for stress analysis. Strain gauges were placed on test materials (a beam and contacting blocks) at locations corresponding to finite element mesh nodes. Testing involved applying loads and measuring strain. Results showed good agreement between experimental and numerical analyses for the linear beam problem. For the nonlinear contacting blocks problem, close placement of strain gauges was important due to high stress gradients at contact points. Small gauge placement errors could cause up to 10% difference in strain measurements. The approach demonstrated that matching strain gauge locations to finite element meshes facilitated accurate validation of numerical models.
The document discusses tensile testing procedures and principles. It outlines the components of a universal testing machine used for tensile testing, including the load frame, load cell, crosshead, and output devices. It then provides details on conducting a tensile test, including specimen preparation, loading procedure, and data collection. Examples are given demonstrating how load and elongation data can be used to determine material properties and how finite element analysis can simulate the effects of strain hardening.
This document summarizes research on evaluating the shear strength of the char layer formed on thermoplastic polyurethane elastomer nanocomposites (TPUNs) used as ablative materials. TPUN samples reinforced with carbon nanofibers and carbon nanotubes were tested using an oxy-acetylene test bed to simulate the extreme heating of a solid rocket motor. Infrared cameras and sensors monitored the sample surface temperature and behavior during testing. A shear strength sensor was used to apply a transverse load to the charred samples until rupture, measuring the reaction force. The maximum force and energy required to fracture the samples were evaluated to determine which material's char layer had the best shear strength performance for insulation applications
This experiment tested the tensile properties of steel, aluminum, and two polymeric materials. Specimens of each material were pulled apart in a tensile testing machine at a constant strain rate to measure properties like yield strength, tensile strength, and elongation. The engineering stress-strain and true stress-strain curves were plotted and compared for each material. Values for properties like Young's modulus, yield stress, and tensile strength were determined from the curves and compared to literature values. Sources of experimental error were also discussed.
The document describes three experiments measuring strain on different surfaces using strain gauges:
1) Measuring strain on an I-beam under varying loads, finding theoretical strain values match measured values. Principal strains are calculated.
2) Measuring strain on a torsional cylindrical rod, calculating principal strains.
3) Measuring combined bending and torsion strain on a circular shaft, calculating principal strains using Mohr's circle.
The experiments aim to observe and compare measured and theoretical strain values using strain gauges and analytical calculations.
This document provides details on the structure and content for a 10-page tensile test report analyzing collected data from destructive tensile testing of an aluminum sample. The report will include sections defining and calculating mechanical properties like proportional limit stress, yield point stress, ultimate tensile stress, breaking stress, modulus of elasticity, modulus of resilience, and modulus of toughness. Graphs and calculations of these properties will be presented along with pages for statistical process control data and summary calculations.
This report summarizes a shock test experiment on a cantilevered aluminum beam. A rotating hammer struck the beam at various angles, and a string gauge measured the resulting deformation. The maximum impact strain of 1876 μ-strain occurred at 20 degrees. Calculations determined the maximum stress on the beam was 18760.69 psi, which is 40.43% of the yield stress for aluminum. The energy loss in the system was approximately 28.5%, and the natural frequency of the beam was 76.92 Hz. The experiment verified relationships between impact energy, beam deformation, and impact angle.
This document provides an overview of key concepts in physics related to motion, including:
- Definitions of terms like speed, velocity, acceleration, displacement, and distance.
- Equations for calculating average speed, velocity, acceleration, and distance traveled with constant acceleration.
- The relationship between time and velocity/distance for objects experiencing constant acceleration due to gravity.
- Centripetal acceleration and the equation relating centripetal acceleration, velocity, and radius of circular motion.
Three samples of 7075 aluminum with intentional defects (a center hole, U-notches, and V-notches) were tested under tension to determine their stress concentration characteristics (K) compared to a reference sample. Theoretical calculations of K matched experimental results, with the hole sample having the lowest K of 2.25 and the U-notch and V-notch samples having similar higher K values of 2.60 and 2.58, respectively. Stress-strain curves were produced for each sample and showed how stress accumulates more at defect points, with the maximum stress given by the product of K and the nominal stress.
Strength of material lab, Exp 2: Tensile test Osaid Qasim
by using our “UTM” machine that
operates on the basis of applying a load in our specimen , so if
we take this force and compare it with change in the length of
specimen “Deformation” we can obtain a (Load-Deformation
diagram) , and by applying this force and divide it by the
specimen cross sectional area we get the Stress ( σ), and divide
the “Deformation” by the original length of the specimen we
will get the Strain (ϵ) , and comparing the stress with strain
results a very Important curve that is characteristic of the
properties of the material and it’s the (Stress-Strain Diagram),
The experiment involves tensile testing of materials using an Instron load frame and BlueHill data acquisition software. Four materials - 6061-T6 aluminum alloy, A-36 hot rolled steel, PMMA, and polycarbonate - were tested with cylindrical specimens containing a reduced gage section. Testing was conducted according to ASTM standards. The data gathered was used to calculate properties like elastic modulus, yield strength, and ultimate tensile strength, which were plotted on stress-strain curves. The purpose was to determine key mechanical properties of each material and familiarize students with tensile testing procedures.
Tensile testing is used to determine the strength and ductility of materials. A specimen is placed in grips and pulled apart under increasing tensile force while measuring elongation. The resulting stress-strain curve provides properties like yield strength, tensile strength, and Young's modulus. Tensile tests are important for engineering design and quality control by ensuring materials can withstand expected loads and comparing new materials. Common applications include testing aircraft components, bolts, and other loaded structures.
- Victor M. Baltazar has over 15 years of experience in quality control engineering and mechatronics. He has a background in quality systems and standards like PPAP, FAIR, APQP, and CP.
- He is bilingual in English and Spanish with expertise in areas such as electrical and mechanical equipment, Microsoft Office, and CAD/CAM software.
- Baltazar held various roles at companies like Gecko Alliance, Micro Precision Calibration Mexico, and SMK Electrónica where he performed tasks like quality inspection, process validation, documentation creation, and equipment calibration.
- Girls often do not choose science careers due to negative stereotypes of scientists in media, a view of science as abstract and irrelevant, and a lack of confidence in math and science abilities.
- Effective science outreach aims to change these subtle attitudes by projecting a positive image of science, emphasizing its social relevance, and showing that success requires practice, not innate ability.
- Presenters should discuss their normal lives, interests in science as a hobby, and diverse people in science to make it seem appealing. They should also stress that math requires practice, not genius, and promote extracurricular clubs to support practice.
#Aprender3C - Profesionalización de las revistas CientíficasAprender 3C
por Solange M. Santos (SciELO Brasil).
Integra la serie de webinars "Transparencia y Buenas prácticas en revistas de acceso abierto" DOAJ & Aprender3C
Fuente: http://aprender3c.org/
Gary Stauffer is applying for employment and feels his 14 years of experience in the oil field makes him a strong candidate. He has worked on rigs and rig-less platforms doing drilling, completion, workover and plug and abandonment work. His qualifications include experience leading rigs safely and efficiently as a tool pusher and supervisor, as well as skills in instrument reading, pressure control, following trends, Microsoft Excel, and safety reporting. He has training in hazards like H2S and first aid.
This document contains a resume for Adetoyinka Oluwarotimi. It summarizes his personal details and professional experience. Some key details include:
- He holds a B.Tech in Chemistry from the Federal University of Technology, Minna and OND in Science Laboratory Technology from the Federal Polytechnic Bida.
- He has worked at the Standards Organisation of Nigeria (SON) since 1999 as an analyst and is currently the Assistant Chief Standard Officer and Quality Management System Auditor.
- His roles at SON include managing quality assurance and auditing their laboratories which are ISO 9001:2008 and ISO 17025 accredited.
- He has over 15 years of experience in analytical chemistry and quality management
Derek Mawhinney has experience as a Merchant Navy Deck Officer and holds a British CoC. He has worked on container ships and bulk carriers for Zodiac Maritime Agencies. Additionally, he has experience working for P&O Ferries on cargo operations and as a bosun for a sail training ship. Mawhinney holds an OOW unlimited deck certificate from the UK Maritime & Coastguard Agency and has completed additional training in areas such as life saving, firefighting, and GMDSS. He has an honors degree in Shipping Operations and completed his cadetship through the Glasgow Nautical Campus.
YouTube: tiempos de costuras: la presencia y ausencia de acontecimientosAprender 3C
La salida del nuevo disco de Leon Gieco generó polémica debido a la inclusión de la canción "Un minuto", que habla sobre la tragedia de Cromagnón de 2004. Los padres de las víctimas se reunieron con Gieco y, luego de esto, el músico decidió eliminar la canción de futuras ediciones del disco. Gieco compuso la canción pensando en Fontanet y en oposición a quienes lo calificaban de "asesino", ya que considera que los Callejeros pueden ser responsables pero lo peor es llamarlos
Analisis Kritis terhadap PERMENDIKBUD NO. 111 Tahun 2014 tentang Bimbingan da...Achmad Badaruddin
Analisis Kritis terhadap PERMENDIKBUD NO. 111 Tahun 2014 tentang Bimbingan dan Konseling di Pendidikan Dasar dan Menengah. Membahas sebutan konselor, pendidikan profesi konselor, pelayanan konseling, jumlah konselor di sekolah, jam konseling di sekolah, manajemen BK di sekolah dan sebagainya. Ini 100% original. Tidak akan ditemukan di buku manapun sejauh ini. 08526 3456 419
Experimental Verification of the Kinematic Equations of Special Relativity an...Daniel Bulhosa Solórzano
The document experimentally verifies the kinematic equations of special relativity and determines the mass and charge of the electron. It describes an experiment that measures the momentum and kinetic energy of electrons over a range of speeds. The data is fitted to both the Newtonian and relativistic kinematic models. The relativistic model provides a much better fit and allows determining the electron charge to mass ratio and mass. The values found agree well with accepted values, supporting the validity of special relativity.
This experiment tested tension and bending using strain gages attached to specimens. For tension, a beam with a 0.53" x 0.125" cross-section was loaded incrementally in a universal tester until maximum load. Strain readings were recorded and averaged. A similar procedure was used for a 1" x 1" bending beam in a four-point bend test. Stress-strain curves were plotted from the data. Young's modulus was calculated from the slopes as 26.7 Mpsi for tension and 55.5 Mpsi for bending, with 11% and 85% errors respectively, likely due to faulty equipment or human error. The goals of introducing strain gage concepts and expanding on Hooke's law and modulus of elastic
The role of strain rate in the dynamic response of materialsAI Publications
We start with the response of ductile materials. To understand the response of these materials to fast dynamic loadings, we introduce two approaches to dynamic viscoplasticity. These are the flowstress approach and the overstress approach, and strain rate has different roles with these two approaches. At very high loading rates the flowstress approach implies very high strength, which is hard to explain by microscale considerations, while the overstress approach does not.We then demonstrate the advantage of using the overstress approach by applying the two approaches to the elastic precursor decay problem. Next use the overstress approach to treat the following problems: 1) the 4th power law response in steady flow of ductile materials; 2) high rate stress upturn (HRSU) of ductile materials; and 3) HRSU of brittle materials. With these examples we demonstrate the advantage of using the overstress approach over the flowstress approach. It follows that HRSU means High (strain) Rate Stress Upturn and not High Rate Strength Upturn, as would follow from using the flowstress approach.
1 February 28, 2016 Dr. Samuel Daniels Associate.docxoswald1horne84988
This report summarizes the procedures and results of an impact force lab experiment. The lab setup included wiring a strain gauge in a half-bridge configuration and using LabView to program sensors and collect data. Data was collected at angle increments of 5 degrees from 5 to 120 degrees and converted from strain to force. The experimental force values followed a sinusoidal trend when plotted against angle. The natural frequency was calculated and compared to the period of oscillation determined from raw waveform graphs, showing similar values between theoretical and experimental results. Some sources of error are noted, including noise in the raw waveform graphs and an incomplete angle range for the data.
Shock wave compression of condensed matterSpringer
This document provides an introduction and overview of shock wave physics in condensed matter. It discusses the assumptions made in treating one-dimensional plane shock waves in fluids and solids. It briefly outlines the history of the field in the United States, noting that accurate measurements of phase transitions from shock experiments established shock physics as a discipline and allowed development of a pressure calibration scale for static high pressure work. It describes some of the practical applications of shock wave experiments for providing high-pressure thermodynamic data, understanding explosive detonations, calibrating pressure scales, and enabling studies of materials under extreme conditions.
NUMERICAL SIMULATION OF WAVES AND FRONTSberezovski
The document summarizes numerical simulations of wave and front propagation in inhomogeneous solids. It discusses:
1) Linear wave propagation in periodic media which results in pulse distortion and decreased propagation velocity compared to homogeneous media.
2) Weakly nonlinear waves in periodic media which form soliton-like pulses with amplitude-dependent speeds.
3) Nonlinear elastic waves in laminates under impact loading that can reproduce experimental stress time histories when nonlinearity is considered.
4) Wave propagation in functionally graded materials where stresses are reduced compared to abrupt interfaces when material properties vary smoothly.
The action potential signal of nerve and muscle is produced by voltage sensitive channels that include a specialized device to sense voltage. Gating currents of the voltage sensor are now known to depend on the back-and-forth movements of positively charged arginines through the hydrophobic plug of a voltage sensor domain. Transient movements of these permanently charged arginines, caused by the change of transmembrane potential, further drag the S4 segment and induce opening/closing of ion conduction pore by moving the S4-S5 linker. The ion conduction pore is a separate device from the voltage sensor, linked (in an unknown way) by the mechanical motion and electric field changes of the S4-S5 linker. This moving permanent charge induces capacitive current flow everywhere. Everything interacts with everything else in the voltage sensor so everything must interact with everything else in its mathematical model, as everything does in the whole protein. A PNP-steric model of arginines and a mechanical model for the S4 segment are combined using energy variational methods in which all movements of charge and mass satisfy conservation laws of current and mass. The resulting 1D continuum model is used to compute gating currents under a wide range of conditions, corresponding to experimental situations. Chemical-reaction-type models based on ordinary differential equations cannot capture such interactions with one set of parameters. Indeed, they may inadvertently violate conservation of current. Conservation of current is particularly important since small violations (<0.01%) quickly (<< 10-6 seconds) produce forces that destroy molecules. Our model reproduces signature properties of gating current: (1) equality of on and off charge in gating current (2) saturating voltage dependence in QV curve and (3) many (but not all) details of the shape of gating current as a function of voltage.
The International Journal of Engineering and Sciencetheijes
1. The document analyzes the behavior of transmission probability in a single rectangular potential barrier where the barrier height and width are scaled by a common factor such that their product remains constant.
2. Expressions for transmission probability are derived for three cases: particle energy greater than, equal to, and less than the barrier energy. Approximations are used to express transmission probability in terms of the constant barrier height-width product.
3. The results show that transmission probability remains constant for particle energy greater than and less than the barrier energy. However, transmission probability decreases with decreasing particle energy when it is equal to the barrier energy.
COLLEGE
PHYSICS LAB REPORT
STUDENTS NAME
ANALYSIS OF A BUBBLE CHAMBER PICTURE
SUPERVISED BY:
19/05/2020
1. Introduction
A bubble chamber is a vessel filled with a superheated transparent liquid (most often liquid hydrogen) used to detect electrically charged particles moving through it. It was invented in 1952 by Donald A. Glaser, for which he was awarded the 1960 Nobel Prize in Physics.
A convenient way to study the properties of the fundamental subatomic particles is through observation of their bubble trails, or tracks, in a bubble chamber. Using measurements made directly on a bubble chamber photograph, we can often identify the particles from their tracks and calculate their masses and other properties. In a typical experiment, a beam of a particular type of particle is sent from an accelerator into a bubble chamber, which is a large liquid-filled vessel. To simplify the analysis of the data, the liquid used is often hydrogen, the simplest element. The use of liquid hydrogen, while it simplifies the analysis, complicates the experiment itself, since hydrogen, a gas at room temperature, liquefies only when cooled to -246◦C. For charged particles to leave tracks in passing through the chamber, the liquid must be in a “super-heated” state, in which the slightest disturbance causes boiling to occur. In practice, this is accomplished by expanding the vapor above the liquid with a piston a few thousandths of a second before the particles enter the chamber.
2. Methods
2.1 Materials needed:
1. student worksheet per student
2. Ruler
3. Scissors
4. Glue stick
5. Pocket calculator
2.2 Procedures
2.2.1 Calculation of the X Particle’s Mass.
Make measurements on each of the photographs. In particular, for each of the circled events measure these four quantities:
· `Σ - The length of the Σ track,
· θ - the angle between the Σ− and π− track,
· s - the sagitta of the π− track,
· `π - The chord length of the π− track.
Your values for the event should be close to those given in the sample input. Run the program using each set of measurements, and tabulate the computed X0 mass from each event. Compute an average of the calculated masses and find the average deviation, expressing your result as Mx ±∆Mx.
Compare your final result with some known neutral particles listed below and identify the X0 particle based on this comparison.
Particlemass (in MeV/c2)
π0 135
K0 498
n 940
Λ0 1116
Σ0 1192
Ξ0 1315
2.2.2 Determination of the Angle θ.
The angle θ between the π− and Σ− momentum vectors can be determined by drawing tangents to the π− and Σ− tracks at the point of the Σ− decay.
We can then measure the angle between the tangents using a protractor. We can show.
COLLEGE
PHYSICS LAB REPORT
STUDENTS NAME
ANALYSIS OF A BUBBLE CHAMBER PICTURE
SUPERVISED BY:
19/05/2020
1. Introduction
A bubble chamber is a vessel filled with a superheated transparent liquid (most often liquid hydrogen) used to detect electrically charged particles moving through it. It was invented in 1952 by Donald A. Glaser, for which he was awarded the 1960 Nobel Prize in Physics.
A convenient way to study the properties of the fundamental subatomic particles is through observation of their bubble trails, or tracks, in a bubble chamber. Using measurements made directly on a bubble chamber photograph, we can often identify the particles from their tracks and calculate their masses and other properties. In a typical experiment, a beam of a particular type of particle is sent from an accelerator into a bubble chamber, which is a large liquid-filled vessel. To simplify the analysis of the data, the liquid used is often hydrogen, the simplest element. The use of liquid hydrogen, while it simplifies the analysis, complicates the experiment itself, since hydrogen, a gas at room temperature, liquefies only when cooled to -246◦C. For charged particles to leave tracks in passing through the chamber, the liquid must be in a “super-heated” state, in which the slightest disturbance causes boiling to occur. In practice, this is accomplished by expanding the vapor above the liquid with a piston a few thousandths of a second before the particles enter the chamber.
2. Methods
2.1 Materials needed:
1. student worksheet per student
2. Ruler
3. Scissors
4. Glue stick
5. Pocket calculator
2.2 Procedures
2.2.1 Calculation of the X Particle’s Mass.
Make measurements on each of the photographs. In particular, for each of the circled events measure these four quantities:
· `Σ - The length of the Σ track,
· θ - the angle between the Σ− and π− track,
· s - the sagitta of the π− track,
· `π - The chord length of the π− track.
Your values for the event should be close to those given in the sample input. Run the program using each set of measurements, and tabulate the computed X0 mass from each event. Compute an average of the calculated masses and find the average deviation, expressing your result as Mx ±∆Mx.
Compare your final result with some known neutral particles listed below and identify the X0 particle based on this comparison.
Particlemass (in MeV/c2)
π0 135
K0 498
n 940
Λ0 1116
Σ0 1192
Ξ0 1315
2.2.2 Determination of the Angle θ.
The angle θ between the π− and Σ− momentum vectors can be determined by drawing tangents to the π− and Σ− tracks at the point of the Σ− decay.
We can then measure the angle between the tangents using a protractor. We can show.
COLLEGE
PHYSICS LAB REPORT
STUDENTS NAME
ANALYSIS OF A BUBBLE CHAMBER PICTURE
SUPERVISED BY:
19/05/2020
1. Introduction
A bubble chamber is a vessel filled with a superheated transparent liquid (most often liquid hydrogen) used to detect electrically charged particles moving through it. It was invented in 1952 by Donald A. Glaser, for which he was awarded the 1960 Nobel Prize in Physics.
A convenient way to study the properties of the fundamental subatomic particles is through observation of their bubble trails, or tracks, in a bubble chamber. Using measurements made directly on a bubble chamber photograph, we can often identify the particles from their tracks and calculate their masses and other properties. In a typical experiment, a beam of a particular type of particle is sent from an accelerator into a bubble chamber, which is a large liquid-filled vessel. To simplify the analysis of the data, the liquid used is often hydrogen, the simplest element. The use of liquid hydrogen, while it simplifies the analysis, complicates the experiment itself, since hydrogen, a gas at room temperature, liquefies only when cooled to -246◦C. For charged particles to leave tracks in passing through the chamber, the liquid must be in a “super-heated” state, in which the slightest disturbance causes boiling to occur. In practice, this is accomplished by expanding the vapor above the liquid with a piston a few thousandths of a second before the particles enter the chamber.
2. Methods
2.1 Materials needed:
1. student worksheet per student
2. Ruler
3. Scissors
4. Glue stick
5. Pocket calculator
2.2 Procedures
2.2.1 Calculation of the X Particle’s Mass.
Make measurements on each of the photographs. In particular, for each of the circled events measure these four quantities:
· `Σ - The length of the Σ track,
· θ - the angle between the Σ− and π− track,
· s - the sagitta of the π− track,
· `π - The chord length of the π− track.
Your values for the event should be close to those given in the sample input. Run the program using each set of measurements, and tabulate the computed X0 mass from each event. Compute an average of the calculated masses and find the average deviation, expressing your result as Mx ±∆Mx.
Compare your final result with some known neutral particles listed below and identify the X0 particle based on this comparison.
Particlemass (in MeV/c2)
π0 135
K0 498
n 940
Λ0 1116
Σ0 1192
Ξ0 1315
2.2.2 Determination of the Angle θ.
The angle θ between the π− and Σ− momentum vectors can be determined by drawing tangents to the π− and Σ− tracks at the point of the Σ− decay.
We can then measure the angle between the tangents using a protractor. We can show.
1. Edwin Hall discovered the Hall effect in 1879 while working on his doctoral degree at Johns Hopkins University. Through his measurements of a tiny effect produced using apparatus he designed, he published findings about a new interaction between magnets and electric currents eighteen years before the electron was discovered.
2. The Hall effect is the production of a voltage difference across an electrical conductor, perpendicular to both the current in the conductor and an applied magnetic field. This effect can be used to determine various properties of the conductor such as carrier concentration and Hall coefficient.
3. Applications of the Hall effect include speed detection, current sensing, magnetic field sensing as in magnetometers, and position sensing in devices like brushless DC motors.
This document summarizes an experimental study that used photoelasticity and a polariscope to analyze stresses in a composite beam made of araldite resin. Researchers applied different loads to the beam and captured fringe patterns using the polariscope. They calculated stresses at various points on the beam based on the fringe patterns and orders. They also used ANSYS software to simulate stresses on the beam and compared the experimental and simulation results. The stresses obtained from both methods matched well, validating the experimental photoelastic technique for analyzing stresses in composite materials.
The experimental research at the University of California, Irvine Wind Tunnel Facility aims to understand how passive scalars are mixed by turbulent air flows. An electrically heated wire grid generates turbulence in the air, acting as a passive scalar. The decay of turbulence and approach to isotropy was analyzed by measuring velocity fields downstream of the grid. The power decay law was validated, with decay exponents of 1.504 and 1.389 for different turbulence intensities. A region of homogeneous isotropic turbulence was established, becoming isotropic farther downstream for higher flow speeds.
The document summarizes several physics experiments on topics like simple pendulums, inclined planes, inertia, and conservation of momentum. It includes the hypotheses, variables, procedures, results and conclusions for each experiment. The experiments are designed to investigate relationships between various physical quantities like the period of a pendulum varying with its length, the velocity of an object on an inclined plane relating to the angle of incline, and momentum being conserved before and after collisions.
1) The document is a revision checklist for additional GCSE science covering topics in physics including forces, motion, braking, terminal velocity, elasticity, energy, momentum, static electricity, electrical circuits, household electricity, current, charge, power, atomic structure, radiation, nuclear fission, and nuclear fusion.
2) It lists key terms, concepts, and formulas to define and explanations to provide for each topic.
3) The checklist provides resources for students to review physics content and ensure they understand the essential information for their GCSE exam.
Millikan's oil drop experiment precisely measured the charge of individual oil droplets falling through an electric field. By measuring the droplets' terminal velocities when falling and rising, Millikan calculated their electrical charges, which were always integer multiples of a single fundamental unit of charge - the electron's charge. Millikan's experiment was the first to directly measure the discrete, quantized nature of electric charge and determine the electron's charge as -1.6022 x 10-19 Coulombs.
This document summarizes several abstracts presented at the AIP Bi-Annual Postgraduate Conference on September 7-8, 2001. The abstracts covered topics related to gravitational waves, opto-acoustic interactions, quantum mechanics, spin waves, frequency sources, phonon lasers, nanostructure fabrication, and silicon nanowire growth. Experimental and theoretical work was presented across various fields of physics including general relativity, quantum physics, condensed matter physics, and nanotechnology.
1. The document discusses principles of quantum chemistry including classical mechanics and its inadequacies in explaining phenomena at the atomic level, Planck's quantum theory, and properties of electromagnetic radiation.
2. Key concepts covered include de Broglie's equation describing the wave-like nature of matter, Heisenberg's uncertainty principle, explanations of photoelectric effect and blackbody radiation.
3. The document also introduces quantum numbers, Hund's rule, Pauli's exclusion principle, and Aufbau's principle, which describe allowable electron configurations in atoms and molecules.
This article describes an experiment to demonstrate delayed-choice quantum erasure using polarization-entangled photon pairs in an undergraduate laboratory setting. The experiment implements two different methods to delay the erasure measurement until after the photons have passed through an interferometer and been detected. Experimental results show interference patterns when the erasure is performed, agreeing with quantum mechanics where the timing of measurements is irrelevant. The experiment allows students to explore fundamental quantum concepts in a hands-on way.
1. Abstract—The purpose of this lab is to find material properties
for two specimens using compressive testing. Students willanalyze
and compare the material properties found by quasi-static and
dynamic loading. The data that was taken on the UTS for the
quasi-staticloading was provided online by the professor. Students
used the Split-Hopkinson Pressure Bar to record data for the
dynamic loading. Students then found the material properties
from this raw data. This was done by using variations of stress and
strain equations as well as using knowledge of wave propagation
theory as it applied to the Split-Hopkinson Pressure Bar. It was
found that the Young’s Modulus and yield strength were higher
for both specimens in dynamic loading compared to quasi-static
loading.
Index Terms—Oscilloscope, Quasi-static loading, Split-
Hopkinson Bar Pressure, Wave Propagation Theory.
I. INTRODUCTION
The purpose of this final lab project is to determine the
material properties that a certain material displays under two
different loading methods, dynamic and quasi-static. If the
strain rate is found to be > 0.01 𝑠−1
, the loading is said to be
dynamic. If strain rate is found to be < 0.01 𝑠−1
, the loading is
said to be quasi-static.The strain rate a material is subjected to
is a large factor in determining its material properties.
To obtain data for the material properties using quasi-static
loading, the Instron 5967 Universal Testing Machine (UTS) is
used. The specimens are subjected to compressive loading
where the UTS will determine the strain for the specific loading.
Students did not physically use the UTS but data was taken and
provided by the professor for analysis and comparisons to the
material properties found by dynamic loading.
In order to obtain data for the material properties using
dynamic loading, students used the Split-Hopkinson Pressure
Bar. Voltage signals will be measured via an oscilloscope.
Fig. 1. Schematic of Split-Hopkinson PressureBar. Consists of 3 steel
bars (striker bar, incident bar, and transmission bar). A strain gage is
attached to the incident and transmission bar. The material is placed in
between the incident and transmission bar.
The strain gage used is in the ½ Wheatstone Bridge
configuration (fig 2).
Fig. 1. 1/2 Wheatstone Bridge configuration.
Once the strain gages are attached, strain can be calculated
using the following equation:
𝜀 =
2Δ 𝑉𝑔
𝑉𝑠 𝐺 𝑓
(1)
where Δ𝑉𝑔 is Vamp divided by the gain (550), 𝑉𝑠 is the
voltage source (5V), and 𝐺𝑓 is the gage factor (2.1).
After strain is calculated Hooke’s Law can be applied to
find strain.
𝜎 = 𝐸𝜀 (2)
The student strikes the incident bar with the mallet, which
will produce a compression wave that travels from the striker
Material Property Testing Under Quasi-Static
and Dynamic Loading
Ballingham, Ryland
Levine, Tevan
Parra, Gina
Section 3259 4/22/16
2. <Section3259 Lab6> 2
2
bar to the incident bar to the transmission bar. Wave
propagation theory is used analyze the experiment. Shown
below is wave propagation in the Split-Hopkinson Pressure
Bar.
Fig. 3. Wave propagation in theSplit-Hopkinson PressureBar.
TABLE I
VALUES CALCULATED FOR THE SPECIMEN
Value Equation
Wave Velocity (𝑪 𝑳)
𝐿 𝑖𝑛𝑐𝑖𝑑𝑒𝑛𝑡 𝑏𝑎𝑟
∆𝑇
(3)
Strain (𝜺 𝒔 )
2𝐶 𝐿 ∫ 𝜀 𝑟
( 𝑡) 𝑑𝜏
𝑡
0
𝐿 𝑠𝑡𝑟𝑖𝑘𝑒𝑟
(4)
Strain Rate
−2𝐶 𝐿 𝜀 𝑟
( 𝑡)
𝐿 𝑠𝑡𝑟𝑖𝑘𝑒𝑟
(5)
Stress
𝐴 𝑖𝑛𝑐𝑖𝑑𝑒𝑛𝑡 𝑏𝑎𝑟
𝐴 𝑠
𝐸𝑏 𝜀 𝑡 (6)
The values calculated from the equations above will be used
to determine material properties of each of the specimens. The
values will also be used to compare with those found by quasi-
static loading. The students will analyze and compare the values
found from both the quasi-static and dynamic loading tests.
II. PROCEDURE
Part 1
In the first week of lab, students familiarized themselves with
the Split-Hopkinson pressure bar and the theory of wave
propagation.Students were shown how to excite the striker bar
with a mallet in order to induce a strain wave that propagates in
the incident bar. The data is collected using a half-bridge
configuration and an oscilloscope. When collecting the data,
having the proper distance (approximately 3 cm) between the
incident bar and striker bar is important for the validity of the
data. After the striker bar is excited by the mallet, data is
obtained using the oscilloscope for later calculations. The
oscilloscope measures strain gage voltages and time and this
data is used to calculate strain wave propagation speed. A
qualitative uncertainty analysis is also performed.
Part 2
The second week of this lab builds on the first week on
lab by adding a transmission bar to the setup. Initially, the
incident bar and transmission bar are in contact with one
anotherin order to see how the strain wave propagates through
both the incident bar and transmission bar. After excitation
using the striker bar, the incident and transmission bars are no
in contact. The data was collected using a half-bridge
configuration and an oscilloscope. The data collected has a
voltage reading for the incident bar strain gage, a voltage
reading for the transmission bar strain gage voltage and a time
reading. This data shows howthe compression wave propagates
through the incident and transmission and reflects back and
forth within the transmission bar.
Part 3
In the last part of this lab, a test specimen was placed
between the incident and transmission bars using Vaseline with
the goal of deforming the specimen. First, dimension
measurements were taken of both the marble and aluminum
specimens using Vernier calipers. Once all the measurements
are taken, the specimens are tested. Testing is done by placing
the specimen between the incident and transmission bars. The
striker bar will be hit with a mallet in order to compress the
specimen. Like in the previous parts ofthis lab,data is collected
using a half-bridge configuration and an oscilloscope. With the
data obtained, material properties of both the marble and
aluminum can be obtained.
III. RESULTS
Results from the UTS and Split-Hopkinson Pressure Bar.
Fig. 4. Voltage vs time plot forincident andtransmissionbars duringdynamic
aluminum specimen testing. Orange represent the transmission bar signal and
blue represents the incident bar signal.
3. <Section3259 Lab6> 3
3
Fig. 5. Strain vs time plot for incident and transmission bars during dynamic
aluminum specimen testing. Orange represent the transmission bar signal and
blue represents the incident bar signal.
Fig. 6. Stress vs strain plot for incident andtransmissionbars duringdynamic
aluminum specimen testing.
Fig. 7. Voltage vs time plot forincident andtransmissionbars duringdynamic
marble specimentesting. Orange represent the transmissionbar signal andblue
represents the incident bar signal.
Fig. 8. Strain vs time plot for incident and transmission bars during dynamic
marble specimentesting. Orange represent the transmissionbar signal andblue
represents the incident bar signal.
Fig. 9. Stress vs strain plot for incident andtransmissionbars duringdynamic
marble specimen testing.
Fig. 10. Stress vs strain plot for incident and transmission bars during quasi-
static aluminum specimen testing.
4. <Section3259 Lab6> 4
4
Fig. 11. Stress vs strain plot for incident and transmission bars during quasi-
static marble specimen testing.
IV. DISCUSSION
Wave Propagation
The student performed three experiments that dealt with
wave propagation. The first of which was done in which there
was no contact between the incident and transmission bars. In
this case, the wave will develop in a way similar to of that in
wave propagation theory. The wave does not pass through the
bars because there needs to be contact between the two bars in
order for it to pass through. Air is not able to transmit energy
sufficiently. The wave will reflect back as tension, instead of
transmitting through. It will keep reflecting back and forth as
compression and tension until the wave stops.
In the second experiment, contact was made between the
incident and transmission bars. In this case, the wave will be
able to pass through the incident bar into the transmission, but
not entirely. This is because the bars are touching, but they do
not make a perfectly smooth surface for the wave to cross fully.
With perfect conditions,the wave would be able to pass through
to the transmission bar and would reflect back as tension. It
would not however be able to be transmitted back to the
incident bar, as tension waves cannot do so without a bonded
surface.
In the third experiment, a specimen was placed between the
incident and transmission bars. In this case, the wave partially
transmits between the incident bar, the specimen, and the
transmission bar as well. The wave will slow down as it goes
through the specimen and then speed up again as it enters the
transmission bar.
Stress in the specimen is proportional to the how much of the
wave is transmitted to the transmission bar. Strain in the
specimen is proportional to how much of the wave is
transmitted back to the incident bar.
Quasi-static Loading
Data from the quasi-static loading tests were provided
online by the professor. First, strain (𝜀) was calculated.
𝜀 =
∆𝐿
𝐿 𝑜
(7)
where 𝐿 𝑜 is the original length of the specimens and ∆𝐿 is the
extension of the specimen.
Stress (𝜎) can also be calculated from the data provided
online. Force (F) was provided along with the specimen
dimensions so stress can be found fromthe formula below.
𝜎 =
𝐹
𝐴
(8)
Where A is the cross sectional area of each specimen based
on the dimensions provided.
With stress and strain now found, Young’s Modulus (E) can
be calculated using the formula below.
𝐸 =
𝜎
𝜀
(9)
This method was used for the ductile (aluminum washer)
and brittle (marble) specimen that underwent quasi-static
loading.
Dynamic Loading
For dynamic loading, the properties of the wave traveling
through the bars were calculated first.
𝜀 =
2Δ 𝑉𝑔
𝑉𝑠 𝐺 𝑓
(10)
where 𝑉𝑠 is the source voltage (~5V), 𝐺𝑓 is the gage factor,
and Δ𝑉𝑔
Δ𝑉𝑔=
𝑉𝑎𝑚𝑝
550
(11)
Wave speed 𝐶 𝐿 through the bar is calculated below.
𝐶 𝐿 = √ 𝐸/𝜌 (12)
where 𝜌 is the density of the bar.
Since the both the incident and transmission bars are the
same materials throughout,the speed through both bars is the
same. With the strain through the incident bar calculated, the
strain in the specimen can be calculated using the following
equation.
𝜀 𝑠
( 𝑡) = −
2𝐶 𝐿
𝑙 𝑠
∫ 𝜀 𝑟
𝑡
0
( 𝑡) 𝑑𝑡 (13)
where 𝜀 𝑟 is strain through the incident bar. The reflected
signal strain was then calculated by performing the trapezoidal
rule on the first hump of the strain vs time curve. The below
equation for strain rate was used to derive equation (12).
𝜀 𝑠̇ = −
2𝐶 𝐿 𝜀 𝑟(𝑡)
𝑙 𝑠
(14)
5. <Section3259 Lab6> 5
5
The stress in the specimen was calculated from the formula
below.
𝜎𝑠 =
𝐴 𝑏
𝐴 𝑠
𝐸𝑏 𝜀 𝑡(𝑡) (15)
where 𝐴 𝑏 is the cross sectionalarea of the bar, 𝐴𝑠 is the cross-
sectional area of the specimen, 𝐸𝑏 is the Young’s Modulus of
the bar, and 𝜀 𝑡(𝑡) is the strain through the transmitted bar as a
function of time through.
The above method was used for the ductile (aluminum washer)
and brittle (marble) specimens.
Analysis and Comparison
Aluminum Specimen (large-washer)
The material properties for aluminum were found using
quasi-static and dynamic testing.The quasi-static test data was
provided on canvas. Table 1 shows the properties found for
each test.
TABLE II
ALUMINUM PROPERTIESFOR QUASI-STATIC/ DYNAMIC TESTS
Testing
Method
Young’s
Modulus
(GPa)
Yield Strength
(MPa)
Ultimate
Strength
(MPa)
Quasi-static 1.22 140 -
Dynamic 5.49 146 191
For a quasi-static compression test, the ultimate strength
value can’t be found because the material never fractures. It
appears that dynamic testing produces a larger value for
Young’s modulus. This is because the strain rate during the
dynamic testing is higher, causing material properties to
change. In most materials, the faster the strain rate the less
ductile the material becomes [1]. Material strength typically
increases with increasing strain rate as well. Due to this, it
makes sense that the Young’s modulus is higher during
dynamic testing. Yield strength were nearly identical for both
cases.
Marble Specimen
The material properties for marble were found using quasi-
static and dynamic testing. The quasi-static test data was
provided on canvas. Table 2 shows the properties of each test.
TABLE III
MARBLE PROPERTIES FOR QUASI-STATIC/ DYNAMIC TESTS
Testing
Method
Young’s
Modulus
(GPa)
Yield Strength
(MPa)
Ultimate
Strength
(MPa)
Quasi-static 3.67 - 64
Dynamic 4.37 - 119
Calculating a value for yield strength for marble wouldn’t make
sense as marble is a brittle material. The value for Young’s
modulus and Ultimate strength is higher for the dynamic test
for both cases. This makes sense because material strength
increases as strain rate is increases.
V. CONCLUSION
This lab was primarily focused on developing stress-strain
curves and material properties based on quasi-static and
dynamic loading tests.Upon doing this lab, it is realized that a
specific stress-strain response is not unique; instead it is based
on the strain rate applied to the specimens. It is clear to see that
material properties for the specimens that underwent dynamic
loading were higher than that of when they went through quasi-
static loading (Table II and Table III).
Improvements can be made to increase the accuracy of the
experiment. The incident bar and transmission bar should have
perfectly flat ends.This will allow the wave to travel smoothly
through the incident bar, to the specimen, and to the
transmission bar. This will obtain more accurate results,as there
will be no hindrance to the path the wave travels. Anotherway
to improve the accuracy of this lab is to run the loading tests
multiple times. This would allow students to better see the
relationship between strain rate and material properties. To find
more material properties, a test can be done in tension instead
of compression. This will illustrate material properties like
toughness, ductility, fracture strength, etc.
APPENDIX
TABLE IV
CALCULATED UNCERTAINTY VALUES
Parameter Value Uncertainty
Gage Factor 2.1 ± 0.0107
Wheatstone Bridge N/A ± 0.35 Ω
Strain Gage N/A ± 0.3%
Calibration
Constant
550 ± 0.5%
Calipers N/A ± 0.001 in
UTM N/A ± 2 x 10−4
m
𝑽 𝑮 5.50 V ± 0.5 V
𝑽 𝑺 5 V ± 0.05 V
𝑬 𝑩𝒂𝒓 200 GPa ± 5 GPa
𝝆 𝑩𝒂𝒓 7865
𝑘𝑔
𝑚3
± 160
𝑘𝑔
𝑚3
𝑪 𝑳 5042
𝑚
𝑠
± 80
𝑚
𝑠
𝑳 𝑺𝒕𝒓𝒊𝒌𝒆𝒓 𝒃𝒂𝒓 0.2286 m ±0.00127 m
𝑳𝑰𝒏𝒄𝒊𝒅𝒆𝒏𝒕 𝒃𝒂𝒓 1.21667 m ± 0.0127 m
𝑳 𝑻𝒓𝒂𝒏𝒔𝒎𝒊𝒔𝒔𝒊𝒐𝒏 𝒃𝒂𝒓 1.2115 m ± 0.0127 m
𝑨 𝑩𝒂𝒓 5.07 x
10−4
𝑚2
± 9.5 x 10−7
m
𝑫 𝑩𝒂𝒓 0.0254 m ± 2.55 x 10−5
m
𝑨 𝒂𝒍𝒖𝒎𝒊𝒏𝒖𝒎 7 x 10−5
m ± 8.9 x 10−7
m
𝑫 𝒂𝒍𝒖𝒎𝒊𝒏𝒖𝒎 0.0158 m ± 2.55 x 10−5
m
𝑻 𝒎𝒂𝒓𝒃𝒍𝒆 9.98 x 10−3
m ± 2.55 x 10−5
m
𝑾 𝒎𝒂𝒓𝒃𝒍𝒆 1.039 x 10−3
m
± 2.55 x 10−5
m
𝑳 𝒎𝒂𝒓𝒃𝒍𝒆 1.026 x 10−3
m
± 2.55 x 10−5
m
𝑨 𝒎𝒂𝒓𝒃𝒍𝒆