Deformations and thermal response of active flexible rods with enbedded shape memory alloy actuators

摘要

The problem of plane deformations of flexible rods with embedded SMA line actuators is considered. A simple formula for calculating the shape change of flexible rods under uniform prestrain of an embedded actuation wire is given. The results are compared with previously obtained results based on a shear-lag model for the evaluation of actuation force, a finite element solution and experimental data. It is shown that the present model gives very good accuracy and simplicity. A thermal analysis of the SMA cool-down from the austenitic finish temperature is also considered in this paper. A solution for heat conduction in a cylindrical rod with off-center heat source is presented. The results show that for common elastomeric flexible materials the rate of heat conduction is slow. As a result frequency control of the thermal cycle in flexible rods is not as efficient as the mechanical shape control.