Shape optimization of SMA structures with respect to fatigue

This paper presents an efficient structural optimization approach for shape memory alloys (SMAs) with respect to fatigue. In the proposed method, a nonparametric shape optimization approach based on optimality criteria is applied to change the structural configuration. The design optimization framework is accomplished by relying on commercially available software and tools. In addition, both low- and high-cycle fatigue criteria are used to compute the fatigue factor at each material point, indicating its degree of safeness with respect to fatigue. Meanwhile, a 3D constitutive model is utilized to predict, with good accuracy, the stabilized thermomechanical stress state of a SMA structure subjected to multiaxial nonproportional cyclic loading. Finally, numerical examples are tested to demonstrate the effectiveness of the proposed method.