Shape recovery mechanics of fiber-reinforced shape-memory polymer composite

摘要

A fiber reinforced thermosetting styrene-based shape-memory polymer composite (SMPC) is developed, and the main objective is to investigate the deployment performances for SMPC. Firstly, the fundamental material properties, such as mechanical properties and shape recovery properties, are evaluated. It indicates that the SMPC shows nonlinear viscoelasticity at a temperature range between T_g -20°C and T_g +20°C. At/above T_g, the shape recovery ratio of SMPC upon bending is above 90%. The shape recovery properties of SMPC become relatively stable after some packaging/deployment cycles. Then, the micro-deformation mechanism is characterized by optical microscopy and SEM. The fiber microbuckling is the primary deformation mechanism in bending of SMPC, and it ensures that the SMPC can achieve high packaging strain and avoid fiber failure. With the microbuckling, SMPC materials are suitable to be used in deployable structure components because of their high strain-to-failure capability. For the analytical research, the relationship between deployment moment and angle is derived by using dynamic theory. It shows that the SMPC shell shows a linear bending stiffness when recovering, and meanwhile performs a self-locking function at the final state because of sharply increase in moment. It implies that SMPC is a good candidate material for deployable structures.