A wood beam AB with a rectangular cross-section (4 in. × 6 in.) serving as a roof purlin is simply supported by the top chords of two adjacent roof trusses. The beam is subjected to distributed load q acting in the vertical direction through the centroid of the purlin cross-section. The top chords of the trusses have a slope a = 278. The purlin has a length L = 75 in. Determine the permissible distributed load q based on the allowable compressive and tensile stress in the beam σ_all = 2 ksi.

Transcribed Image Text:

L A y q B h α