고체역학 (Beer) — Shearing Stresses in Beams: Problem 6.5

6.5 The rolled-steel beam shown has been reinforced by attaching to it two $12 \times 175\text{-mm}$ plates, using $18\text{-mm-diameter}$ bolts spaced longitudinally every $125\text{ mm}$. Knowing that the average allowable shearing stress in the bolts is $85\text{ MPa}$, determine the largest permissible vertical shearing force.