Design of shape memory alloy sandwich actuators: an analytical and numerical modelling approach

Shape memory alloy (SMA)-based actuator composites are characterised by a high force output which is activated by a temperature increase. In this work we exploit this property to design sandwich structures with SMA-matrix composite actuator skins capable of exhibiting a reversible, tailored flexural response. A theoretical model which predicts the resultant deflection and flexural moment produced as a result of selectively actuating one of the system skins was developed and confirmed using a multi-step Finite Element (FE) analysis which takes into account the fabrication pathway through which these systems may be manufactured. The model correlates the geometric parameters and material properties of the various components making up the system and provides a quantitative description of the role which each variable plays in determining the overall sandwich actuator performance. This is necessary for the future production and implementation of such systems in real-life applications.