Thermal Postbuckling Characteristics of Laminated Conical Shells with Temperature-Dependent Material Properties

Abstract

The nonlinear thermoelastic buckling/postbuckling characteristics of laminated circular conical/cylindrical shells subjected to uniform temperature rise are studied employing semi-analytical finite element approach based on first-order shear deformation theory and field consistency principle. The nonlinear governing equations, con- sidering geometric nonlinearity based on von Karman's assumption for moderately large deformation, are solved using Newton-Raphson iteration procedure coupled with displacement control method to trace the prebuck- ling/postbuckling equilibrium path. The presence of asymmetric perturbation in the form of small magnitude load spatially proportional to the linear buckling mode shape is assumed to initiate the bifurcation of the shell deforma- tion. The study is carried out to highlight the influences of semicone angle, number of layers, material properties, and number of circumferential waves on the nonlinear thermoelastic response of the laminated circular coni- cal/cylindrical shells. The participation of axisymmetric and asymmetric modes in the total response of the shells is brought out through the deformation shape analysis. The comparison of thermoelastic pre- and postbuckling characteristics of shells with temperature-dependent material properties is made with those considering constant material properties, and the behavior is found to be significantly different depending upon the shell parameters and degradation rate of material properties. The shells exhibit softening type of prebuckling nonlinear response and snap-through-type/stable postbuckling response depending upon the geometrical/material parameters.