Thermo-mechanical Interlaminar Stress and Dynamic Stability Analysis of Composite Spherical Shells

Abstract

Three-dimensional Finite Element Method (FEM) based thermo-mechanical stress analysis of a laminated Fibre Reinforced Polymer (FRP) composite made spherical shell structure subjected to an elevated thermal filed has been carried out. FE simulation has been carried out through ANSYS 14.0, using Brick 8-node solid 185 layered elements. Shell structures due to curvature effect show thermo-mechanical stress concentration effects not only at the edges but also at various other critical locations in its domain. Appropriate FE mesh size has been adopted to capture these stress concentration effects and has been established through validation with analytical results. Out-of-plane thermo-mechanical interlaminar stresses (σrr, τθr, τɸr) has been assumed to be responsible for damage initiation and hence have been analysed in details in order to reveal the critical ply-interface. In order to study dynamic stability of the shell structure under thermal environment, different lamination schemes have been adopted ([0/θ]4, θ 00, 150, 300, 450, 600,750, and 900). It has been observed that, plies oriented parallel to the cantilevered edge of the shell structure are providing minimum deformation under an elevated thermal environment. However, the laminated shell shows a geometrically non-linear behaviour as the ply-orientation angle has been varied.