고체역학 (Gere) — Shear Forces and Bending Moments: Problem 4.3-9

4.3-9 A curved bar $ABC$ is subjected to loads in the form of two equal and opposite forces $P$, as shown in the figure. The axis of the bar forms a semicircle of radius $r$. Determine the axial force $N$, shear force $V$, and bending moment $M$ acting at a cross section defined by the angle $\theta$.