The Effect of Thermoplastic Composite Processing on the Performance of Embedded Nitinol Actuators

Abstract

Intelligent materials are a class of material systems currently being devel oped for numerous applications. They usually consist of a composite or hybrid material system with fibrous or distributed actuators, various sensors and control modules The nitinol or shape memory alloy wire actuator is currently being developed for use in intelli gent material systems. In order for the nitinol actuator to be a reliable part of the adaptive hybrid system, the effect of the composite manufacturing on the nitinol performance must be determined. The results of a study investigating the effects of a "high temperature" ther moplastic composite processing cycle on the nitinol actuator are presented. The actuators were exposed to a number of thermoplastic processing cycle simulations at 400°C. Criti cal parameters, such as processing time, training of the actuators, and type of nitinol actu ators, were varied to determine their effect on the performance of the nitinol actuator. With processing times from 5 to 20 minutes, the nitinol actuator demonstrated a useable recovery stress (σ ur) between 173-265 MPa. The σ ur of unprocessed actuators, thermoset processed actuators and actuators embedded in an actual APC-2 composite material are compared to the data from the simulation tests. The performance of the embedded nitinol actuators agree well with the simulation.