The thermomechanical behavior of shape memory alloys (SMAs) may be modeled either by microscopic or macroscopic point of view. Shape memory, pseudoelasticity and thermal expansion are phenomena related to the SMA behavior. Constitutive models consider phenomenological aspects of these phenomena. The present contribution considers a one-dimensional constitutive model with internal constraint to describe SMA behavior including the effect of plastic strains. The proposed theory contemplates four phases: three variants of martensite and an austenitic phase. Different material parameters for austenitic and martensitic phases are considered. Thermal expansion phenomenon and plastic effects are also contemplated. Hardening effect is represented by a combination of kinematic and isotropic behaviors. A plastic-phase transformation coupling is incorporated into the model. A numerical procedure is developed and numerical results show that the proposed model is capable to capture the general thermomechanical behavior of shape memory alloys.

Smart materials have a growing technological importance due to their unique thermomechanical characteristics. Shape memory alloys belong to this class of materials being easy to manufacture, relatively lightweight, and able to produce high forces or displacements with low power consumption. These aspects could be exploited in different applications including vibration control. Nevertheless, literature presents only a few references concerning the experimental analysis of shape memory alloy dynamical systems. This contribution deals with the experimental analysis of shape memory alloy dynamical systems by considering an experimental apparatus consisted of low-friction cars free to move in a rail. A shaker that provides harmonic forcing excites the system. The vibration analysis reveals that shape memory alloy elements introduce complex behaviors to the system and that different thermomechanical loadings are of concern showing the main aspects of the shape memory alloy dynamical response. Special attention is dedicated to the analysis of vibration reduction that can be achieved by considering different approaches exploiting either temperature variations promoted by electric current changes or vibration absorber techniques. The results establish that adaptability due to temperature variations is defined by a competition between stiffness and hysteretic behavior changes.