The influence of orthotropy principal directions of a bilayered conical shell on the limit load in elastic and elastic-plastic stress state

The objective of the paper is to derive the equations and presenting the method of solution of elastic-plastic stability problem of an open bilayered conical shell with nonhomogeneous precritical stress state developed by a composed external load. An iterative solution procedure, algorithm of calculation and source code were elaborated and tested. Next, a comparative analysis was performed for isotropic and orthotropic materials, and the critical loads were determined for orthotropic layers with variable direction of principal axes of orthotropy in specific layers. The finite element method was also used to perform the analysis of stress distribution, strains and displacements and the results were compared for different layer thickness and variable material properties.