Sandwich structures with tunable damping properties: On the use of Shape Memory Polymer as viscoelastic core

A Shape Memory Polymer (SMP), the tBA/PEGDMA, is used as viscoelastic core in sandwich structures. The dynamic mechanical characterization of this SMP highlights promising damping properties. The composite sandwich is developed by coupling the SMP with aluminum skins. The SMP core temperature is tuned from the Time-Temperature Superposition Principle through a rainbow calibration curve in order to correspond to optimal values of damping ratio in the frequency range of interest. The damping performances predicted by a Finite Element model are validated experimentally using modal analysis. The experimental results are found to be in good agreement with the predictions of the Finite Element model. Furthermore, it is found that the controlled heating of the SMP core allows damping the structure over a wide frequency range. The methodology which is proposed in this paper is applicable to any viscoelastic material exhibiting frequency - and temperature - dependent high damping properties.