고체역학 (Beer) — Pure Bending: Problem 4.47

4.47 A concrete slab is reinforced by 5/8–in.-diameter steel rods placed on 5.5-in. centers as shown. The modulus of elasticity is \( 3 \times 10^6 \) psi for the concrete and \( 29 \times 10^6 \) psi for the steel. Using an allowable stress of 1400 psi for the concrete and 20 ksi for the steel, determine the largest bending moment in a portion of slab 1 ft wide.