Abstract:

Adaptive wings may promise a significant improvement in aerodynamic performance of airplanes. The shape memory alloy (SMA) torsion actuator is one of the key issues in actuator technologies for adaptive wings. Nickel-Titanium alloy wire is the sort of SMA in common use, and it possesses special mechanical properties. SMA torsion actuator has been made up of NiTi wires and a thin-walled tube,in which plastically elongated wires are winded on a tube with a certain angle referenced to the generatrix of the tube, and pasted on its surface. By controlling recovery strain and recovery force of SMA wires, SMA torsion actuator can yield torsion deformation and moment, thus can manage the wing spanwise torsion. In this paper, a primary mechanical model of SMA torsion actuator is established, and the relationship between the torsion angle of the tube and the temperature is analyzed theoretically and verified by experiments. In an experimental system, the AOA of a wing model connected with SMA torsion actuator can be changed continuously up to 15°, and good agreement is obtained between analytical and experimental data.

Key words: SMA, to rsion actuator, mechanical model, ex per imental analy sis