Design On Variable Stiffness Space Deployable Structure Based On Shape Memory Polymer Composite

Shape-memory polymer composite (SMPC) is belonged as one of the novel smart materials, due to its structural fundamental and the capability of active shape-changing. One of the most desirable potentail applications of SMPC in space depolyable structure is promising. It is expected to would play a revolutionary role in the development and application of SMPC in the active and depolyable structure in space.On this background, carbon fiber reinforced epoxy-based SMPC was fabricated and designed to meet the requirment the aircraft and aerospace application. In subsquence, the SMPC structure was designed and optimized for the depolyable space SMPC hingle and truss. The main work is summarized as follows:(1) The thermomechanical properties, static mechanical properties, and dynamic mechanical properties of SMPC had been testified, respectively. All related parameters were obtained from the experiments and employed to the theoretical euqations of laminated composites, to calculate the modulus constants. And then, the theoretical results were therefore compared with the experimental results. It was found that there was a great agreement between theoretical and experimental results in this study.(2) Consequence, the experimental results and constrants were used as the basic parameters for design, by introducing the theoretical euqations of laminated composites and theoretical mechansic of materials. Here, we then simulated and design the geometrical shape, material constituents, thickness and thermal actuation for the SMPC through using the ABAQUS software. Based on these simulation results, the structure and design of SMPC were achieved.(3) The SMPC was prepared and designed as the main constituent in the hingle and truss structures, and obtain the design model for these two structures. The dynamic ADAMS software was used to simulate in the following step. Based on this dynamic software, the dynamic characteristics of hingle and truss structures made from SMPC had been testified. On the other hand, the analysis, output moment of force, as well as relationship between stress and strain had been carried out and verified.(4) Meanwhile, the hinge and truss structures had been fabricated and designed on the basis of simulation results. We therefore carried out the tests for the deployable solar panel and truss on the ground to simulate the special aerospace environment. From the simulation tests, we obtained the corresponding experimental results, and compared them with the simulation results to verify the theoretical validity. We compared actual laminate reply force with the output torque of bending laminate in finite element simulation; compared the actual process of the solar actuated by two hinges with the process of the solar actuated by two hinges in dynamics simulation; compared the actual process of truss unfolding with process of truss unfolding in dynamics simulation. The validities of design and simulation of space deployable hinge and truss had been well agreement with the experimental results.One of the most desirable potentail applications of SMPC in space depolyable structure is researched in this thesis. The results show that the shape memory composite material has good material performance, can meet the requirements of the space environment on the material, and is suitable for application in space depolyable structure.