Question

Page 7 of 9 Q4. (30%) Composite Beam Three identical wooden beams and two identical steel plates are bolted together to form the composite shown in the sketch. Determine the largest allowable bending moment, Malom, when the member is bent about the horizontal axis. Include sketch of transformed area, and list all assumptions and equations. Material/Properties Wood Steel Elastic Modulus 2,900,000 psi 29,000,000 psi Allowable Normal Stress 3,000 psi 18,000 psi 10 in 2.5 in 0.25 in a) Determine n b) Sketch the transformed area c) Calculate the section properties d) Setup the equations for calculating stresses in wood and steel as functions of moment, respectivel Determine the controlling allowable normal stress that controls the magnitude of e)

Answer 1

2y) Fransforwed widn of wood aP 2-dactual 2-5 -0-25 ir 0 25 woocd sechion to teel Section 04 661 inch 12- 12 i stess , mÎnenbem wcodend steel will be some t. whene Wshess in wwoo Gall-for steel Kooops. 4 steel ㅘ çtressed to 18000 psi wood uril be stessed Sooo 1800 psí Cfrom equation butgoo psi is less oan wood's allowable Stsess which s 3ooo psi. and-stress G,"cap steel so Mall- Cafstee)-3450b-in (Ans)