고체역학 (Beer) — Shearing Stresses in Beams: Problem 6.46

6.46 Three $20 \times 450\text{-mm}$ steel plates are bolted to four $L152 \times 152 \times 19.0$ steel angles to form a beam with the cross section shown. The bolts are of $22\text{-mm}$ diameter and are spaced longitudinally every $125\text{ mm}$. Knowing that the allowable average shearing stress in the bolts is $90\text{ MPa}$, determine the largest permissible vertical shear in the beam. (Given: $I_x = 1901 \times 10^6 \text{ mm}^4$.)