고체역학 (Beer) — Stress and Strain—Axial Loading: Problem 2.112

2.112 For the composite bar of Prob. 2.111, if \(P\) is gradually increased from zero to 98 kips and then decreased back to zero, determine (a) the maximum deformation of the bar, (b) the maximum stress in the tempered-steel bars, (c) the permanent set after the load is removed. Context from Prob. 2.111: Two tempered-steel bars, each \(3/16\) in. thick, are bonded to a \(1/2\)-in. mild steel bar. This composite bar is subjected to a centric axial load of magnitude \(P\). Both steels are elastoplastic with \(E = 29 \times 10^6\) psi and with yield strengths equal to 100 ksi and 50 ksi, respectively, for the tempered and mild steel. The length of the bar is 14 in. and its width is 2.0 in.