On the thermally induced bistability of composite cylindrical shells for morphing structures

The multistability of composite thin structures has shown potential for morphing applications. The present work combines a Ritz model with path-following algorithms to study bistable cylindrical panels. Polynomial discretisations of the displacements field are used to predict stable shapes' geometry and other aspects of the nonlinear structural behaviour. In order to improve the inherently poor conditioning properties of Ritz approximations of slender structures, a non-dimensional Shell Lamination Theory with Sanders nonlinear strains is developed and presented. An investigation on the relative importance of different nonlinear strain terms is shown to provide useful insight into the applicability of common assumptions about shell kinematics. In the current approach, we continue numerical solutions in parameter space, that is, we path-follow equilibrium configurations as the control parameter varies, find stable and unstable configurations and identify bifurcations. The numerics is carried out using a set of in-house MATLAB (R) routines for numerical continuation. Results are compared with detailed finite elements analysis throughout the course of the paper. (C) 2011 Elsevier Ltd. All rights reserved.