고체역학 (Gere) — Stresses in Beams (Basic Topics): Problem 5.11-5

5.11-5 A box beam is constructed of four wood boards as shown in the figure part a. The webs are $200\text{ mm} \times 25\text{ mm}$ and the flanges are $150\text{ mm} \times 25\text{ mm}$ boards (actual dimensions), joined by screws for which the allowable load in shear is $F = 1.1\text{ kN}$ per screw. (a) Calculate the maximum permissible longitudinal spacing $s_{\max}$ of the screws if the shear force $V$ is $5.3\text{ kN}$. (b) Repeat part (a) if the flanges are attached to the webs using a horizontal arrangement of screws as shown in the figure part b.