Optimal Design of Shape Memory Alloy Compositeunder Deflection Constraint.

Shape-adaptive or morphing capability in both aerospace structures and wind turbineblade design is regarded as significant to increase aerodynamic performance and simplifymechanisms by reducing the number of moving parts. The underlying bistable behavior ofasymmetric cross-ply composites makes them a suitable candidate for morphing applications. Todate, various theoretical and experiential studies have been carried out to understand and predictthe bistable behavior of asymmetric laminates and especially the curvature obtained in their stableconfigurations. However, when the bi-stable composite plate is integrated with shape memory alloywires to control the curvature and to snap from a stable configuration to the other (shape memoryalloy composite, SMAC), the identification of the design parameters, namely laminate edge length,ply thickness and ply orientation, is not straightforward. The aim of this article is to present theformulation of an optimization problem for the parameters of an asymmetric composite laminateintegrated with pre-stressed shape memory alloys (SMA) wires under bi-stability and a minimumdeflection requirement. Wires are modeled as an additional ply placed at the mid-plane of thecomposite host plate. The optimization problem is solved numerically in MATLAB and optimaldesign variables are then used to model the SMAC in ABAQUS™. Finite element results arecompared against numerical results for validation.