Boeing and NASA have been developing lightweight and compact SMA actuators to support a growing need for improved aircraft efficiency and reduced emissions. Boeing Research and Technology has successfully integrated and deployed shape memory alloy actuator systems for various flight tests and wind tunnel model applications.
The Boeing effort on the Spanwise Adaptive Wing (SAW) project included the development, integration, and test of a compact integrated SMA actuator system to fold the outboard wing sections of the Prototype-Technology Evaluation Research Aircraft UAV during flight. Nickel-titanium-hafnium SMA torsional components were processed by Boeing to produce stable actuation at loads up to 400 inch-pounds and 88 degrees of angular range.
The SMA components were incorporated into a hinge assembly that mechanically coupled the inboard wing and the outboard folding winglet. A compact on-board control system used angle, torque, and temperature readings to command and maintain a range of wingtip angles over a wide variety of flight and test conditions.
An integrated simulation of the SMA actuators was developed to aid in the design of the actuator control system and for preflight performance predictions. The simulation was deployed using compact electronics and integrated into NASA’s flight simulator. This complete actuator system was tested using a combination of bench and wind tunnel testing prior to integration into the vehicle. The performance of the actuator control system, the SMA actuation, and the actuator simulation model were validated during three flight tests at Roger’s Dry Lake in December of 2017.
Abstract of Spanwise Adaptive Wing: Shape Memory Alloy Actuation System for In-Flight Wing Folding, by Mr. Micheal Bass, Mr. James H. Mabe, Boeing Company, Berkeley, Missouri.
Dr. Othmane Benafan, NASA Glenn Research Center, Cleveland, Ohio.
Dr. Stefan Bieniawski, Ms. Hannah Arntson, Boeing Company, Tukwila, Washington.
Presentation is from SMST 2019, May 13 – 17, Kostanz, Germany
https://www.asminternational.org/web/smst-2019/registration
