고체역학 (Gere) — Stresses in Beams (Advanced Topics): Problem 6.3-9

6.3-9 A simple beam that is 5.5 m long supports a uniform load of intensity q. The beam is constructed of two angle sections, each L 150 × 100 × 10, on either side of a 50 mm × 200 mm (actual dimensions) wood beam (see the cross section shown in the figure part a). The modulus of elasticity of the steel is 20 times that of the wood. (a) If the allowable stresses in the steel and wood are 110 MPa and 8.3 MPa, respectively, what is the allowable load \( q_{allow} \)? Note: Disregard the weight of the beam, and see Table F-5 of Appendix F for the dimensions and properties of the angles. (b) Repeat part (a) if a 25 mm × 250 mm wood flange (actual dimensions) is added (see figure part b).