Experiments and Simulations on the Shape Memory Process of Thermally-Induced Shape Memory Polymer Composite Thin-Wall Structure Considering Progressive Damage

As a deployable mechanism and structural integrated component, the shape memory polymer composites (SMPCs) will inevitably be damaged during folding and storage. However, damage effects on the shape memory behaviour of the SMPCs lack thoroughly investigations. This article aims to research the entire shape memory process of the SMPCs with the consideration of progressive damage. Firstly, uniaxial tensile tests and DMA tests with three-point bending mode are conducted to obtain basic mechanical properties and shape memory capabilities of the SMPCs. A 5 cm-long SMPCs thin-wall tube is subsequently applied in radial flattening and shape recovery experiments. The thin-wall tube's damage state and shape recovery process are investigated and evaluated in detail. The Von-Mises and 3-D Hashin's failure criteria are applied on damage evaluation of pure polymer matrix and yarns, respectively. As a result, a homogenized stiffness degradation model was developed through multi-scale analysis method. The homogenized progressive damage model is combined with the shape memory constitutive equation based on phase transition theory to form a simplified algorithm to accurately describe the mechanical behaviour of the SMPCs in the shape memory process. The algorithm is implemented by user subroutine UMAT of finite element analysis packages Abaqus. It is verified that the proposed algorithm could accurately describe the mechanical behaviour for the SMPCs in entire shape memory process.