고체역학 (Beer) — Pure Bending: Problem 4.42

4.42 The \(6 \times 12\text{-in.}\) timber beam has been strengthened by bolting to it the steel reinforcement shown. The modulus of elasticity for wood is \(1.8 \times 10^6 \text{ psi}\) and for steel is \(29 \times 10^6 \text{ psi}\). Knowing that the beam is bent about a horizontal axis by a couple of moment \(M = 450 \text{ kip}\cdot\text{in.}\), determine the maximum stress in (a) the wood, (b) the steel.