고체역학 (Gere) — Stresses in Beams (Basic Topics): Problem 5.6-11

5.6-11 A beam $ABC$ with an overhang from $B$ to $C$ is constructed of a UPN 260 channel section with flanges facing upward (see figure). The beam supports its own weight (372 N/m) plus a triangular load of maximum intensity $q_0$ acting on the overhang. The allowable stresses in tension and compression are 138 MPa and 75 MPa, respectively. (a) Determine the allowable triangular load intensity $q_{0,allow}$ if the distance $L$ equals 1.2 m. (b) What is the allowable triangular load intensity $q_{0,allow}$ if the beam is rotated 180° about its longitudinal centroidal axis so that the flanges are downward?