A thick-walled cylindrical pressure vessel as shown in Figure 2 is subjected to an internal pressure p, and has stress components: 6 O(TT) 1, 0 (zz) = {, where Q = (2+ -1). Assume that the pressure vessel is made of steel with elastic modulus E = 200 GPa, Poisson's ratio v= = 0.3, yield strength oys=1000 MPa, inner radius a = 1.0 m, outer radius b = 1.2 m, and length L = 10 m. Calculate the pressure pi at first yielding using the von Mises and Tresca conditions. Calculate the change in the wall thickness and axial dimension L of the vessel at yielding. (30 points) > J (00) = _ wit Fig. 2 (2x) CLA (FT)