고체역학 (Beer) — Pure Bending: Problem 4.90

4.89 and 4.90 For the beam indicated, a couple of moment equal to the full plastic moment \( M_p \) is applied and then removed. Using a yield strength of 42 ksi, determine the residual stress at (a) \( y = 1 \text{ in.} \), (b) \( y = 2 \text{ in.} \) 4.90 Beam of Prob. 4.76. [From Prob 4.76: The beam has an I-shaped cross section with top and bottom flanges of width 3 in. and thickness 1 in., and a web of thickness 1 in. and height 2 in. The material is elastoplastic with \( E = 29 \times 10^6 \text{ psi} \) and \( \sigma_Y = 42 \text{ ksi} \).]