A modified model of shape memory phenomena with return point memory

摘要

An amount of martensite phase in shape memory alloys (SMAs) depends not only on temperature and externally applied stress, but also on the previous thermomechanical loading history. In our paper, the constitutive model for hysteresis phase transition proposed by Ivshin and Pence is modified to obtain a model that is consistent with 'return point memory', a property of shape memory alloys that has been experimentally verified by a number of authors, as well as by our own experiments. The model is completed by equations that enable to calculate recovery tensile stresses generated in a constrained shape memory alloy specimen during thermal cycling. An illustrative example of the recovery stress transformational loops due to constrained thermal cycling is presented. It is shown that the simulated stress-temperature loops include return point memory behavior.