Basic properties and application of shape memory polymer composite to deployable hinge for solar arrays

Abstract

This paper is concerned about the basic properties of deployment of shape memory polymer composite (SMPC) and its application to deployable hinge for solar arrays. Shape memory polymer (SMP) used in this study is a thermoset styrene-based shape memory resin in contrast to normal thermoplastic SMPs. Carbon fiber fabric reinforced SMPC is discussed here. In order to investigate the basic performances of deployment for SMPC hinge, the experimental methods are used as follows: dynamic mechanical analysis (DMA), three point bending test and deployment tests. Results indicate that the glass transition temperature (T_g) of SMPC is approximate 63°C. SMPC shows typical linear elasticity and high bending modulus before glass transition in SMP, while exhibits apparent nonlinear viscoelasticity and low bending modulus within the range of glass transition in SMP. The shape recovery ratio of SMPC is above 90% at/above T_g, while drops sharply at below T_g. The deployment properties of SMPC depend strongly on the number of thermomechanical cycles, which become relatively stable after some packaging/deployment cycles. Moreover, deployment velocity and shape recovery ratio rise remarkably with the increase of temperature of SMPC. In the end, a prototype of solar array actuated by SMPC hinge, which is heated by passing an electrical current, deploys from about 180° to 0° in one minute. This SMPC hinge performs good deployment performances during numerous thermomechanical cycles.