고체역학 (Beer) — Pure Bending: Problem 4.70

4.70 For the solid square rod of Prob. 4.69, determine the moment \( M \) for which the radius of curvature is \( 3 \text{ ft} \). (From Prob. 4.69: A solid square rod of side \( 0.6 \text{ in.} \) is made of a steel that is assumed to be elastoplastic with \( E = 29 \times 10^6 \text{ psi} \) and \( \sigma_Y = 48 \text{ ksi} \). Knowing that a couple \( M \) is applied and maintained about an axis parallel to a side of the cross section...)