고체역학 (Gere) — Stresses in Beams (Basic Topics): Problem 5.6-6

5.6-6 A simple beam of length \( L = 5\text{ m} \) carries a uniform load of intensity \( q = 5.8\text{ kN/m} \) and a concentrated load \( 22.5\text{ kN} \) (see figure). (a) Assuming \( \sigma_{\text{allow}} = 110\text{ MPa} \), calculate the required section modulus \( S \). Then select the most economical wide-flange beam (HE shape) from Table F-1 in Appendix F, and recalculate \( S \), taking into account the weight of the beam. Select a new beam if necessary. (b) Repeat part (a), but now assume that the design requires that the HE shape must be used in weak axis bending (i.e., it must bend about the 2–2 (or \( y \)) axis of the cross section).