Pressurization service cycles.
Please help me solve problem 2.A thin-walled cylindrical pressure vessel made of titanium alloy Ti-6AI-4V with outside diameter Do= 720 mm and wall thickness of t = 6 mm is subjected to repeated pressurization service cycles from minimum zero to maximum 6 MPa pressure, P. Static loads are applied in the form of an axial tensile load, F, of 300 kN, and an applied moment, M, of 60 kN•m. It is designed for a service life, A, of 106 cycles. Perform analysis on a stress element on the OUTSIDE surface of the pressure vessel where the tensile stresses are maximum (element shown in the diagram below). a. Perform fatigue analysis to determine the safety factors in stress, Xs, and life, XN. Use von Mises for effective stress amplitudes, and use the SWT equation for the mean stress equation to determine equivalent completely reversed stress amplitude. b. Use the octahedral shear stress yield criterion (von Mises) to determine the safety factor against yielding. c. Check for Leak-Before-Break-Criterion and determine the safety factor on crack length, Xa.
