Shape Memory Alloys Applied to Automotive Adaptive Aerodynamics.

Shape memory alloys (SMAs) are gaining popularity in the fields of automotive and aerospace engineering due to their unique thermomechanical properties. This paper proposes a numerical implementation of a comprehensive constitutive model for simulating the thermomechanical behavior of shape memory alloys, with temperature and strain as control variables to adjust the shape memory effect and super elasticity effect of the material. By implementing this model as a user subroutine in the FE code Abaqus/Standard, it becomes possible to account for variations in material properties in complex components made of shape memory alloys. To demonstrate the potential of the proposed model, a skid plate system design is presented. The system uses bistable actuators with shape memory alloy springs to trigger plate movement. The kinematics and dynamics of the system are simulated, and effective loads are generated by the shape memory alloy state change due to the real temperature distribution in the material, which depends on the springs' geometrical parameters. Finally, the performance of the actuator in switching between different configurations and maintaining stability in a specific configuration is assessed. The study highlights the promising potential of shape memory alloys in engineering applications and demonstrates the ability to use them in complex systems with accurate simulations.