Mechanical analysis of a tip-loaded deployable truss based on shape memory polymer composite
A tip-loaded deployable truss (TLD truss) with gusseted base and auxiliary support frame has been developed to carry a heavy tip load. This paper presents details in a sequence of material characterization, structure description, finite element analysis, and mechanical experiments. It uses carbon fabric reinforced cyanate-based shape memory polymer composite as the driving source to unfold the packaged truss. The glass transition temperature of the shape memory polymer composite is 195 °C. The recovery moment of the composite increases first and then decreases with the increase of the recovery ratio. Three different structural forms have been compared by modal analysis and swept sine simulations; results show that the TLD truss with a tip load of 1.3 kg has the highest stiffness. Thus it was selected and manufactured to carry out a series of experiments, including swept sine vibration, acceleration and shock testings of the packaged TLD truss, and modal testing of the deployed TLD truss. No damage was observed, indicating the TLD truss has a relatively high stiffness and could withstand the required mechanical environment.