Question

1. During a stress-strain test, the unit deformation at a stress of 5,000 psi was observed to be 0.000167 in./in. and at a stress of 20,000 psi it was 0.000667 in./in. If the proportional limit is 30,000 psi, what is the modulus of elasticity? What is the stress corresponding to a strain of 0.0002 in./in.? Would these results be valid if the proportional limit were 18,000 psi? Explain. 2. A steel wire 30 feet long, hanging vertically, supports a load of 500 lb. Neglecting the weight of the wire, determine the required diameter if the stress is not to exceed 20,000 psi and the total elongation is not to exceed 0.20 in. Assume that E-29 x 106 psi. 3. An aluminum bar having a cross-sectional area of 0.25 sq. in. carries the axial loads applied at the positions shown. IfE 10 x 106 psi, compute the total deformation of the bar. 8000 1b0 3000 Ib 7000 lb 2000 lb 4 5'

Numbers: 1-7

Answer 1

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