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) ...
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 ...
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 ...