Solution Behavior of the Transient Heat Transfer Problem in Thermoelectric Shape Memory Alloy Actuators

The main purpose of this paper is to study the solution behavior of the transient heat transfer problem for one-dimensional symmetric thermoelectric shape memory alloy (SMA) actuators. It is proved that for the transient cooling problem with constant electric current density of magnitude |J | there is a value J0 of |J | such that when |J | < J0, the temperature in SMA is always decreasing to its steady state, and when |J | > J0, the temperature in SMA may not be always decreasing, which is an important property of thermoelectric SMA actuators reported by Lagoudas and Ding [Internat. J. Engrg. Sci., 33 (1995), pp. 2345–2364]. A lower bound of J0 is given. The physical implications of main results are also discussed.