A simply supported composite beam with a 3.6 m span supports a triangularly distributed load of peak intensity q0 at mid span (see figure part a). The beam is constructed of two wood joists, each 50 mm x 280 mm, fastened to two steel plates, one of dimensions 6 mm x 80 mm and the lower plate of dimensions 6 mm x 120 mm (see figure part b). The modulus of elasticity for the wood is 11 GPa and for the steel is 210 GPa. If the allowable stresses are 7 MPa for the wood and 120 MPa for the steel, find the allowable peak load intensity q0,max when the beam is bent about the z axis. Neglect the weight of the beam.

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6mm × 80mm steel plate 50 mm 280 mm wood joist 280 mn 6mm × 120 mm steel plate 4o A 1.8 m 1.8 m