Shape memory polymers are smart materials characterized by a recoverability memory effect and a large strain, but their mechanical properties such as low stiffness need to be improved for mechanical applications with large recovering force. Researchers have reported that the characteristics of shape memory polymers can be significantly improved when the shape memory polymers are used with fiber–reinforced composite material. In this study, a carbon fiber fabric-reinforced shape memory polymer composite hinge was designed, fabricated, and characterized for space deployable structure applications. The main idea is that the carbon–epoxy composite itself and the shape memory polymer are combined, which means both epoxy resin and shape memory polymer resin are used together and the epoxy resin remains in a B-stage after curing. As such, the stiffness and shape recovery ratio are increased. The shape memory polymer composite hinge specimens with four plies of carbon fiber fabric and a shape memory polymer were prepared for the experiment. The glass transition temperature, which was 70.9°C, was determined using dynamic mechanical analyzer. The effect of temperature on shape recovery capability was investigated. We investigated the reasons of damage evolution to shape memory polymer composite tapes occurring in the folding and deploying process. To do that, damage to the hinge was observed with a USB digital microscope and a scanning electron microscopy and then explained with ABAQUS analysis. The results confirm that the shape memory polymer composite hinge is a good candidate for an antenna in spacecraft in space.

This study introduces a method for measuring the blocking force of a shape memory polymer composite hinge to quantify the performance of a shape memory polymer composite hinge for space deployable structure applications. A detailed design of how to select heating elements for a self-deployable configuration is also suggested. The shape memory polymer composite hinge consists of two reverse carpenter shape memory polymer composite tapes that were made from carbon-epoxy fabric, shape memory polymer resin, and two heating elements. The heating elements were attached to the shape memory polymer composite tape using the composite manufacturing method, and they were used as the heating source in the deployment test. The blocking force and moment of the hinge were measured using a pulley–mass system setup to examine the mechanical performance of the hinge. During the test, the shape change was recorded with a camera to calculate the moment arms. While the blocking force was 7.21 N in the initial test, it decreased slightly with the working cycle and was 6.27 N in the repeated test. The maximum hinge moment was 0.47 N m in the repeated test. In addition, the results revealed that a pop-up phenomenon occurred at the middle period of deployment. These results confirm that the shape memory polymer composite hinge works well with heating elements and provide a guideline for performance evaluation of the shape memory polymer composite hinge.

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