고체역학 (Gere) — Stresses in Beams (Advanced Topics): Problem 6.5-2

6.5-2 A beam with a channel section is subjected to a bending moment \( M \) having its vector at an angle \( \theta \) to the \( z \) axis (see figure). Determine the orientation of the neutral axis and calculate the maximum tensile stress \( \sigma_t \) and maximum compressive stress \( \sigma_c \) in the beam. Use a UPN 200 channel section with \( M = 0.75 \text{ kN}\cdot\text{m} \) and \( \theta = 20^\circ \).