Postbuckling Behavior of Angle-Ply Laminated Joined Circular Conical-Cylindrical Shells

Abstract

The prebuckling and the postbuckling behaviors of the angle-ply composite laminated joined circular conical-cylindrical shells subjected to torsion, external pressure, axial compression, and thermal loading are studied considering the variation of stiffness coefficients along the meridional direction in the conical section. The analysis is carried out using the semi-analytical finite element method based on the first-order shear deformation theory. The nonlinear governing equations, derived using Sanders-type kinematic relations, are solved using the Newton-Raphson iterative technique coupled with the displacement control method to trace the prebuckling followed by the postbuckling equilibrium path. The presence of asymmetric perturbation in the form of a small magnitude load spatially proportional to the linear buckling mode shape is considered to initiate the bifurcation of the shell deformation. The influences of the semicone angle, the ply angle, and the number of circumferential waves on the prebuckling/postbuckling response of the angle-ply laminated joined circular conical-cylindrical shells are investigated. The critical buckling load shows a decreasing trend for positive semicone angle cases and an increasing one for negative semicone angle cases with the increase in the magnitude of the semicone angle of the mechanically loaded shells. The shells with a positive semicone angle mostly depict asymmetric bifurcation buckling under uniform decrease in temperature whereas the shells with a negative semicone angle depict asymmetric bifurcation buckling under a uniform rise in temperature. The ratio of the minimum load in the postbuckling path and the critical buckling load may significantly be lower than unity depending upon the shell parameters and loading situations.