A Unified High-Order Semianalytical Model and Numerical Simulation for Bistable Polymer Composite Structures.

Bistable polymer composite structures are morphing shells that can change shape and maintain two stable configurations. At present, mainly two types of bistable polymer composite structures are being studied: cross-ply laminates and antisymmetric cylindrical shells. This paper proposes a unified semianalytical model based on the extensible deformation assumption and nonlinear theory of plates and shells to predict bistability. Moreover, the higher-order theoretical model is extended for better prediction accuracy, while the number of degrees of freedom is not increased; this ensures a lower computational cost. Finally, based on these theoretical models, the main factors affecting the stable characteristic of the two bistable polymer composite structures are determined by comparing the models of various orders. The main challenges in describing the bistable behavior, such as bifurcation points and the curvatures of stable states, are addressed through prediction of the corner transversal displacement in stable configurations. The results obtained from the theoretical model are validated through nonlinear finite element analysis.