Problem 5.8-11 A square wood platform, 8 ft 3 8 ft in area, rests on masonry walls (see figure). The deck of the platform is constructed of 2 in. nominal thickness tongue-and-groove planks (actual thickness 1.5 in.; see Appendix F) supported on two 8-ft long beams. The beams have 4 in. 3 6 in. nominal dimensions (actual dimensions 3.5 in. 3 5.5 in.). The planks are designed to support a uniformly distributed load w (lb/ft 2 ) acting over the entire top surface of the platform. The allowable bending stress for the planks is 2400 psi and the allowable shear stress is 100 psi. When analyzing the planks, disregard their weights and assume that their reactions are uniformly distributed over the top surfaces of the supporting beams. (a) Determine the allowable platform load w 1 (lb/ft 2 ) based upon the bending stress in the planks. (b) Determine the allowable platform load w 2 (lb/ft 2 ) based upon the shear stress in the planks. (c) Which of the preceding values becomes the allowable load
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