A mechanical contact model for superelastic shape memory alloys

Shape memory alloys (SMA) are nowadays widely used in different industries. The two extraordinary behaviors of superelasticity and shape memory effect make these alloys a super wear-resistant material. In a range of SMA applications, contact between adjacent surfaces occurs. In this research, a formerly-developed contact model, which individually considers each asperity, is extended to cases where superelastic shape memory alloys are used. Since constitutive equations of SMAs are based on stress and strain, to establish a relationship between classical contact models and the main arguments of these constitutive equations, a representative strain based on the pseudoelastic behavior of SMAs was defined. Experiments were conducted to verify the model’s predictions. In these experiments, a NiTi wire was pressed against a Steel plate; then, the measured penetration in the test and the values predicted by the contact model were compared. The reported results show an acceptable agreement between theory and experiment.