Stevens, E 321
Excerpt: ... Tensile Testing and Mechanical Properties Assessment Performance Criteria The student will be able to: 1. Draw a schematic stress-strain diagram and identify: the elastic region, the plastic region, the yield stress, the ultimate tensile stress, the elongation to failure, and the elastic modulus. 2. Draw schematic stress-strain diagrams which broadly illustrate the differences in tensile behavior between different materials and materials classes. 3. Describe the role of stress concentrators in the failure of both brittle and ductile materials. Background Ohring Callister Procedure 1. The Elastic Modulus of Nylon Fishing Line In groups of two, determine the elastic modulus characteristic of nylon fishing line. Nylon is a generic name given to a family of related polymers. 100/200 lb test nylon monofilament fishing line has been hung from the lab ceiling. Use a set of calipers to determine the diameter of the line. Measure the distance of a fiducial mark on the line from the floor. Add a known weight to the cla ...
Iowa State, ME 325
Excerpt: ... M E 325 - Review for Exam 1 The Design Process What are the steps involved? What is the distinction between analysis and synthesis? Where are there possibilities for iteration? Factor of Safety What is a factor of safety? What kinds of questions should an engineer ask about a factor of safety? How should an engineer interpret a factor of safety How do you compute a factor of safety? Materials and Processing ductility brittleness fracture toughness impact resistance hardness even materials - uneven materials can you interpret a stress-strain diagram what is a proportional limit? where is it on a stress-strain diagram? can you tell if a material is ductile or brittle? where is the yield point where is the ultimate tensile strength point where is the fracture point what are quenching, tempering and annealing what properties do these processes impart? Optimization single variable multivariable - no constraints and with constraints can you set up the appropriate Hessian Matrix? what is + definite? - definite? s ...
Iowa State, ME 325
Excerpt: ... M E 325 - Review for Exam 1 The Design Process What are the steps involved? What is the distinction between analysis and synthesis? Where are there possibilities for iteration? Factor of Safety What is a factor of safety? What kinds of questions should an engineer ask about a factor of safety? How should an engineer interpret a factor of safety How do you compute a factor of safety? Materials and Processing ductility brittleness fracture toughness impact resistance hardness even materials - uneven materials can you interpret a stress-strain diagram what is a proportional limit? where is it on a stress-strain diagram? can you tell if a material is ductile or brittle? where is the yield point where is the ultimate tensile strength point where is the fracture point what are quenching, tempering and annealing what properties do these processes impart? Optimization single variable multivariable - no constraints and with constraints can you set up the appropriate Hessian Matrix? what is + definite? - definite? s ...
Wisconsin, MATERIAL S 350
Excerpt: ... Mechanical Testing Overview Steven Segal MS&E 350 10/9/07 A. The Purpose of Mechanical Testing a. Aids in the selection of an engineering material for a particular application b. Provide information of empirical, rather than fundamental, significance. c. Collected data/info is useful to designers, fabricators, and researchers B. Types of Testing a. Tension/Compression Test i. Tests the ability of a material to carry a static load b. Hardness Test i. Evaluates a material's resistance to plastic deformation c. Impact Test i. Determines the toughness of a material to conditions of shock loading d. Fatigue Test i. Evaluates the useful lifetime of a material under cyclic loading conditions e. Creep and Stress-rupture Test i. Evaluates the strength and useful lifetime of materials subject to a load at elevated temperatures for long periods of time The Tension Test Equations: a) Engineering Stress b) Engineering Strain c) Ultimate Tensile Strength d) Percent Elongation e) Percent Reduction in Area f) ...
Iowa State, AE 340
Excerpt: ... th an oblique angle of 30o a coefficient of friction of 0.306, and a forward speed of the mower is zero (so that the velocity of the knife relative to the plants coincides with the velocity of the knife relative to the mower. (a) Will the plant material slide along the edge when the knife moves toward the countershear? (b) What is the minimum coefficient of edge friction that will prevent sliding? Question 11.6 Assume an alfalfa plant with a stem diameter of 3 mm, stem modulus of elasticity of 1,800 N/mm2, and ultimate tensile strength of 35 N/mm2 is being cut at a height of 60 mm above the ground, i.e., the plant roots fix the stem to the ground and the knife loads the stem as a cantilever beam. (a) How large must the knife force be to load the plant fibers to their ultimate stress? (b) How far would the stem deflect when the plant fibers reached their ultimate stress? Question 11.8 Use Equations 11.10 and 11.11 to generate a curve of knife force versus knife displacement (ranging from 0 to 9 mm) during the ...
Fairfield, ME 311
Excerpt: ... Min. Ultimate Tensile Strengths of Common Spring Wires 400 From Hamrock, Table 17.2 & Eqn. 17.2 350 300 Sut (KSI) 250 Music Wire Chrome Silicon 200 Chrome Vanadium Oil-Tempered 150 Hard Drawn 100 0.010 0.100 Wire Diameter (in) 1.000 ...
Kettering, IME 301
Excerpt: ... IME 301 Engineering Materials Laboratory Seven: Tensile Testing Data Sheet Describe the tensile testing procedure. Material Properties Material Ductility Modulus Fracture Strength Ultimate Tensile Strength Yield Strength This data sheet is for your use. It should not be turned in with the homework. ...
Rose-Hulman, ME 328
Excerpt: ... 10. HW Assignment 1 a) We pick a microhardness test such as Knoop or Vickers. b) We look on Figure 6.18 and see that Rockwell C of 50 is about 500 on the Brinell hardness scale. The ultimate tensile strength will be (500 psi) x 500 = 250000 psi, or 250 ksi. ...
Grand Valley State, EGR 309
Excerpt: ... Grand Valley State University Padnos School of Engineering EGR 309-03: Machine Design Lab 5: Tensile Testing Jed Pipe Dale Slotman Professor Demmon 6-5-03 Abstract In this laboratory experiment, three materials were tested using a tensile tester. Stress strain curves were derived from the load and elongation results. The ultimate tensile strengths were used to determine exact material types and the material properties were compared to the measured results. The measured forces at yield and ultimate forces compared well to calculated forces from the published strengths. The measured modulus of elasticity, however, did not match well with the published value for all materials. Problem Statement The purpose of this lab was to gain experience with tensile testing of materials. Three materials were tested to determine material composition by calculating material properties. Procedure & Apparatus Equipment Used Instron Model 5582 Tensile Tester PC with Excel XP EGR 309 Lab 5 Handout Procedure ...
University of Michigan, MECHENG 382
Excerpt: ... ME 382 Lecture 02 THREE IMPORTANT TERMS FOR MECHANICAL DESIGN Stiffness: Ability of an object to resist deformation A stiff object can support large loads with little deformation A compliant object has large deformations under low loads Strength: ...
USC, AME 101L
Excerpt: ... l bar increases in length from 10 cm to 10.02 cm under an applied force of 500 lbf. (a) What is the stress in the bar? (b) What is the strain in the bar? (c) What is the change in diameter of the bar? (Note that the volume of the bar isn't constant; to answer this question you'll have to use Poisson's ratio.) Problem #5 (25 points) a) Measure the thickness of the wall of a can of your favorite carbonated beverage (other than beer; since almost all of you are under 21 I can't condone you testing cans containing a substance you can't legally drink!) Also measure the diameter of the can. b) Compute the cross-section area of the wall, i.e. x diameter x thickness c) The body of the can is made from 3004 aluminum alloy. Find (on the internet, or wherever) the ultimate tensile strength of this alloy. Multiply this strength by the cross-section area of the wall to estimate the tensile force that the wall of the can can withstand. d) Divide this force by the area of the end of the can, i.e. x diameter2/4, to determi ...
Cornell, CEE 3040
Excerpt: ... CEE 304 - Section #8 Example Problems (10-26-04) Confidence Intervals for Small Samples: 1. An environmental engineer is studying the concentration of organics in a groundwater source for a rural water supply. Twelve samples yielded a sample mean and variance of 24.3 g/l and 81 (g/l)2, respectively. a.) Construct a 99% confidence interval for the true mean concentration of organics in this source of water assuming individual observations have a normal distribution. b.) What is the probability the true mean value is contained in the particular interval you just calculated? 2. The sample average ultimate tensile strength for a sample of 35 high-strength magnetic alloy steel rings used in turbine generators was 152.3 ksi, while the sample standard deviation was 4.8 ksi. Obtain a 99% confidence interval for the true average tensile strength of such rings. 1 Hypothesis Testing Example Devore, Sec. 8.1, #11 The calibration of a scale is to be checked by weighing a 10-kg test specimen 25 times. Sup ...
Stanford, ME 111
Excerpt: ... y Su u f E Sf Rm Tm 2 Lets look at some typical uniaxial test stress-strain curves: Low-carbon steel = P A0 = L L0 Annealed high-carbon steel, aluminum = P A0 = 10/3/00 ME111 Lecture 3 L L0 3 Brittle Material - Cast Iron = P A0 Fracture Note that this material has no linear elastic range = L L0 10/3/00 ME111 Lecture 3 4 Material property data that can be determined from a uniaxial test: Measure of Elasticity Youngs modulus E= b a b a Measures of Strength Yield strength Sy = Sy = Py A0 Py Offset yield strength Ultimate tensile strength Fracture strength A0 P Su = u A0 P Sf = f A0 10/3/00 ME111 Lecture 3 5 2. Measures of Ductility Measures ability of a material to accommodate inelastic deformation without fracturing Ductility (fracture strain) f = Lf L L Ductility ratio f y rd = f > 5% -> ductile material 3. Measures of Toughness (or Impact Resistance) Modulus of Resilience: Rm = P ...
Washington, ME 354
Excerpt: ... Mechanical Properties of Materials In Tension by Patrick McAdams Laboratory Section AA, Tuesday 2:30 p.m., January 30, 2007 Daniel Flores Date of Laboratory: February 5, 2007 Report Submitted to: Jiangyu Li EXECUTIVE SUMMARY Three samples of four materials underwent tensile strain until fracture. These materials were 1018 steel, 6061-T6 aluminum, polycarbonate, and polymethylmethacrylate (PMMA). The tensile test was done using a 5585H Instron tensile test machine. During these tests, stress and strain was measured every tenth of a second. Using these stresses and strains, engineeringstress vs. engineering strain curves were created for each sample. With these curves, modulus of elasticity, yield strength, ultimate tensile strength, strain at fracture, modulus of resilience, and modulus of toughness were determined. From the strain at fracture, the ductility was looked at qualitatively for the materials. Steel, aluminum, and polycarbonate were observed to be ductile and, as a result, experienced necking ...
Iowa State, ME 324
Excerpt: ... ME 324 : Manufacturing Engineering HW #1 1.Using the same scale for stress, we note that the tensile true stress-true strain curve is higher than the engineering stress-strain curve. Explain whether this condition also holds for a compression test. 2.You are given the K and n values of two different materials, respectively. Is this information sufficient to determine which material is the tougher? If not, what additional information do you need, and why? 3.A paper clip is made of wire 1.5 mm in diameter. If the original material from which the wire is made is a rod 20 mm in diameter, calculate the longitudinal and diametrical engineering and true strains that the wire has undergone during processing. 4.Calculate the ultimate tensile strength (engineering) of a material whose strength coefficient is 700 MPa and a tensile-test specimen which necks at a true strain of 0.35. 5.A cable is made of three parallel strands of different materials, all behaving according to the equation s = Ke n .their properties and cr ...
Washington, MSE 170
Excerpt: ... LAB V MECHANICAL TESTING Study Questions: 1. The following engineering stress-strain data points were obtained for a 0.20% C plain-carbon steel: Stress (MPa) Strain (%EL) 0 0 207 0.1 379 0.2 414 0.5 469 1.0 496 2.0 510 4.0 524 6.0 517 8.0 503 10.0 476 12.0 448 14.0 386 16.0 352 19 fractu re a. b. c. d. e. f. Plot the stress strain curve. Determine the ultimate tensile strength of the alloy Calculate the elastic modulus of the alloy Determine the 0.2% offset yield stress of the alloy Determine the percent elongation (%EL) at fracture What kind of behavior is demonstrated ductile or brittle? 2. Using the ASM and ASTM handbooks online or in the engineering library, compare the values you calculated in question 1 above to the reference values. 3. Sketch your approximation of the stress strain curves of the following materials on one plot. 1018 Steel 2024 Aluminum Carbon Fiber Nylon 6,6 360 Brass 316 Stainless Steel 4340 Steel From your sketch, it should be easy to compare the yield strength, ultimat ...
Iowa State, ME 325
Excerpt: ... Failure Theories- Static Loading Maximum Normal Stress Theory Maximum Shear Stress Theory Distortion Energy Theory Common features of these theories: 1. They describe explicit mathematical relationships that relate external loading to stress at critical points in the multi-axial state of stress. 2. They are based on critical physical properties of the materials that are measurable 3. Each theory relates the state of stress to a measurable criterion of failure In general all failure theories say the same thing: When the maximum value of stress or strain in a multi-axial state of stress equals or exceeds the value of stress or strain that produces failure in a uni-axial stress test, the part fails. Maximum Normal Stress Theory Failure will occur in the multi-axial state of stress when the maximum principal normal stress exceeds the ultimate tensile or compressive strength, Sut, or Suc, respectively. if p> Sut, or Suc the part will fail 3 Sut Suc Sut 1 Suc According to the Maximum Normal Stress Theor ...