Theoretical and numerical investigation of the elastic-plastic behavior of thick-walled cylinders

This chapter presents a theoretical and numerical investigation of the elastic-plastic behavior of thick-walled cylindrical pressure vessels loaded by combined large hydrostatic pressure and axial force. A novel approach is introduced for developing general theory, considering material behavior with nonlinear isotropic hardening. The adopted constitutive law is based on applying the von Mises yield criterion in association with the normality rule. The resulting stress and strain distributions are obtained and presented for a case study of combined internal pressure and axial load. The theoretical analysis is validated by comparing the results with those obtained numerically using nonlinear finite element simulation. This investigation addresses a persisting unresolved problem and provides a solution which results in continuous stress and strain fields throughout the cylinder wall. Earlier attempts cited in literature provided incorrect solutions due to invalid assumptions and/or inadequate selection of the yield criterion. The findings provide valuable information in the safety design of extremely loaded pressure vessels and establish the basis for further research in this field