plywood

Problem 587
A beam carries two concentrated loads P and triangular load of 3P as shown in Fig. P-587. The beam section is the same as that in Fig. P-577 on this page. Determine the safe value of P if f_b ≤ 1200 psi and f_v ≤ 200 psi.
 

Problem 577
A plywood beam is built up of 1/4-in. strips separated by blocks as shown in Fig. P-577. What shearing force V will cause a maximum shearing stress of 200 psi?