Chapter 14, Problem 14.47SP

Four wood boards $1$ in. by $\text{6}$ in. in cross section are stacked as shown and used as an $\text{8}$ -ft- long simply supported beam. A $\text{4}00$ -lb concentrated load is applied at the center of the span Neglecting the weight of the beam, calculate the following based on the full nominal (rough) dimensions:

Problem 14.47 (a) the maximum bending stress (boards not glued together)

(b) the maximum bending stress if the boards are glued together

(c) the maximum shear stress in the middle glued joint