고체역학 (Beer) — Pure Bending: Problem 4.168

4.167 Steel links having the cross section shown are available with different central angles $\beta$. Knowing that the allowable stress is 12 ksi, determine the largest force $P$ that can be applied to a link for which $\beta = 90^\circ$. 4.168 Solve Prob. 4.167, assuming that $\beta = 60^\circ$.