Shape Memory Alloy Adaptive Technologies for Aeronautics and Space Applications

From control surfaces to valves to landing gears, aircraft and space systems depend on reliable actuators to control components throughout the entire operations. These actuators demand an optimal volume/performance ratio, lightweight and a long life which for the most part has been fulfilled using conventional actuators such as hydraulic or electric motors. Nonetheless the need for lighter weight systems, more compact systems with higher energy densities are intensely sought for enabling more efficient aerospace systems. With the advent of new actuator forms, a shape memory alloy (SMA) actuator, a more efficient aircraft/spacecraft can be envisioned. SMAs are a unique class of multifunctional materials that have the ability to recover large deformations and generate high loads in response to thermal and/or mechanical stimuli. SMA benefits realized at the system and vehicle level transcend many disciplines, including aerodynamic, structural and controls. This enables a practical solution for reconfigurable/adaptive systems, and provides a variety of benefits to a range of platforms in subsonic or supersonic, transport or fighter, manned or unmanned vehicles. This presentation describes the current state of SMA research that has led to new material systems capable of operating at temperatures and loads relevant to aircraft environments. A discussion as to historical inhibitors of shape memory alloy applications, and how 10 years of research efforts spearheaded by the NASA Glenn Research Center has addressed these challenges and primed the aerospace market for future shape memory actuation successes.