고체역학 (Beer) — Shearing Stresses in Beams: Problem 6.86

6.86 Solve Prob. 6.85, assuming that the thickness of the beam is reduced to $1/4$ in. (Prob. 6.85: The cantilever beam $AB$, consisting of half of a thin-walled pipe of $1.25$-in. mean radius and $3/8$-in. wall thickness, is subjected to a $500$-lb vertical load. Knowing that the line of action of the load passes through the centroid $C$ of the cross section of the beam, determine (a) the equivalent force-couple system at the shear center of the cross section, (b) the maximum shearing stress in the beam. (Hint: The shear center $O$ of this cross section was shown in Prob. 6.74 to be located twice as far from its vertical diameter as its centroid $C$.))