A Novel Design of a Torsional Shape Memory Alloy Actuator for Active Rudder

Area of Science:

• Materials Science and Engineering
• Mechanical Engineering
• Aerospace Engineering

Background:

• Shape Memory Alloy (SMA) actuators offer lightweight and compact alternatives to conventional actuation systems.
• SMA torsional actuators are gaining traction for applications requiring rotational motion, simplifying modules and reducing weight.
• Active rudder systems in aeronautics present a growing demand for efficient and reliable electrical actuation.

Purpose of the Study:

• To present the conceptual design, operating principles, and experimental characterization of SMA torsional actuators.
• To evaluate the working performance of these actuators for an active rudder application in aeronautics.
• To confirm the functionality and performance of a bi-directional SMA torsion spring-actuated device.

Main Methods:

• Conceptual design and development of a pair of SMA torsion springs for bi-directional actuation.
• Utilized Joule heating and natural cooling for actuator operation.
• Experimental characterization and performance testing of the active rudder system.

Main Results:

• The developed active rudder system using SMA torsion springs demonstrated successful functionality.
• A rotation angle of approximately 30° was achieved at a heating current of 5 A.
• The study identified relatively slow operating speed as a key drawback for rudder positioning.

Conclusions:

• SMA torsional actuators are feasible for active rudder applications, offering advantages in weight and compactness.
• The experimental results validate the performance of the SMA torsion spring-actuated device.
• Operating speed limitations can be addressed through advanced control strategies and minor actuator mechanism modifications.