A wood beam in a historic theater is reinforced with two angle sections at the outside lower corners (see figure). If the allowable stress in the wood is 12 MPa and that in the steel is 140 MPa, what is the ratio of the maximum permissible moments for the beam before and after reinforcement with the angle sections? See Appendix F Table F-5(b) for angle section properties. Assume that E_w = 12 GPa and E_s = 210 GPa.

Transcribed Image Text:

240 mm L 102 x 76 x 6.4 480 mm 102 mm -6.4 mm