Effect of pseudoelastic hysteresis of shape memory alloy springs on the aeroelastic behavior of a typical airfoil section

The literature on aeroelasticity includes studies on the use of smart materials as sensors and actuators in vibration control problems. Although different smart materials are available, shape memory alloys have received growing attention in aerospace applications. The hysteretic response of shape memory alloys exhibiting pseudoelasticity provides energy dissipating and damping capabilities for these materials, and therefore, the effectiveness of the pseudoelastic behavior of shape memory alloys has been investigated for passive structural vibration control. However, its effect on the aeroelastic behavior of lifting surfaces has not been covered in the literature. Hence, this article addresses the modeling and analysis of a 2-degree-of-freedom typical aeroelastic section with shape memory alloy springs introduced through the pitch degree of freedom. A state-space model is employed for the simulations of the coupled system, and a two-state approximation to Theodorsen aerodynamics is used for the determination of the aerodynamic loads. The effects of the hysteretic behavior of the shape memory alloy springs on the aeroelastic behavior of the typical section are investigated at the flutter boundary and at post-flutter regime.