고체역학 (Beer) — Transformations of Stress and Strain: Problem 7.121

7.121 Solve Prob. 7.120, assuming that the magnitude $P$ of the two forces is increased to 120 kN. (Reference Prob. 7.120: A pressure vessel of 250-mm inner diameter and 6-mm wall thickness is fabricated from a 1.2-m section of spirally welded pipe AB and is equipped with two rigid end plates. The gage pressure inside the vessel is 2 MPa, and centric axial forces $P$ and $P'$ are applied to the end plates. Determine (a) the normal stress perpendicular to the weld, (b) the shearing stress parallel to the weld.)