Large displacement stability analysis of elastic–plastic unsymmetrical sandwich cylindrical shells

The paper presents stability analysis of elastic–plastic, free supported sandwich cylindrical shell with unsymmetrical faces, loaded by longitudinal forces, transversal pressure, and shear. The J2 incremental Prandtl–Reuss plastic flow theory constitutive relations were used in the analysis and it was assumed that geometrical strain-displacement relations are nonlinear ones. It was also assumed that the shell faces have different thicknesses and these are made of different isotropic compressible materials with linear stress-hardening. Active loading processes are accepted in the analysis, the stability equations are derived using strain energy formulation. Ritz method is used to solve the equations and an iterative computational algorithm was elaborated to get numerical results.