고체역학 (Beer) — Torsion: Problem 3.151

3.151 A steel pipe of 12-in. outer diameter is fabricated from \(\frac{1}{4}\)-in.-thick plate by welding along a helix that forms an angle of \(45^\circ\) with a plane parallel to the axis of the pipe. Knowing that the maximum allowable tensile stress in the weld is 12 ksi, determine the largest torque that can be applied to the pipe.