ES230 Strength of Materials Lesson 7: Properties of Materials I

HOMEWORK (SOLUTION) 0. MecMovie M3.1 and M3.2 (do not hand in). Be sure to hit the “continue” button throughout these, as this will show

graphical illustrations as specimens deform, etc. 1. MecMovie M3.3. As with previous MecMovie assignments, simply print out the results page and hand it in. 2. A metal specimen with a diameter of 0.500 inches and a 2.0-inch gage length was tested to fracture, in tension.

Load and deformation data is given below. Graph the stress-strain BY HAND (do not use Excel), using two different scales (see Philpot Figure P3.16, as an example). Then, determine:

A. The proportional limit: 56.3 ksi (see graph) B. The modulus of elasticity (if the data is “noisy”, use a best-fit until the proportional limit): 30,450ksi

(see graph) C. The ultimate strength: 97.3 ksi (see graph) D. If the specimen had a distinct yield, locate this value on the graph and report it. If the specimen did not

have a distinct yield, determine the yield strength using 0.2% offset. The specimen had a distinct yield: Yield strength 66.7 ksi (lower yield 63.8 ksi)

E. The fracture stress: 81.0 ksi (see graph)

F. The true fracture stress if the final diameter at the location of the fracture was 0.387 inches: 135 ksi

Load Delta lbs inches psi in/in0 0 0 0.00000

2690 0.0009 13700 0.000455670 0.0018 28877 0.000908360 0.0028 42577 0.0014011050 0.0037 56277 0.0018512540 0.0042 63866 0.0021013150 0.0046 66972 0.0023013140 0.006 66921 0.0030012530 0.0079 63815 0.0039512540 0.0098 63866 0.0049012840 0.0121 65394 0.0060512840 0.0139 65394 0.0069512540 0.0209 63866 0.0104512540 0.0255 63866 0.0127514930 0.0487 76038 0.0243517020 0.0835 86682 0.0417518220 0.1252 92794 0.0626018820 0.1809 95849 0.0904519110 0.2551 97326 0.1275519110 0.2968 97326 0.1484018520 0.3107 94322 0.1553517620 0.3246 89738 0.1623016730 0.3339 85205 0.1669516130 0.3385 82149 0.1692515900 Bang 80978

ES230 Strength of Materials Lesson 7: Properties of Materials I

ES230 Strength of Materials Lesson 7: Properties of Materials I

ES230 Strength of Materials Lesson 7: Properties of Materials I

5. A steel member with a cross-sectional area of 1.5 in2 is 25-feet long and is made from the same material tested in the

previous problems. If the steel member was subjected to a force of 135 kips, determine the length of the member when the 135 kips is applied. Then, determine the length of the member after the 135 kips is removed.