Study of a Torque Limiter Based on NiTi Pseudoelastic Tapes

Herein, a new torsional device based on shape memory alloy elements and operating as torque limiter is presented. It consists of a set of pseudoelastic NiTi tapes working in series configuration. The tapes are assembled radially with respect to the rotational direction and work sequentially in beam-like bending mode. The trend of the resulting torque may span from pulsating to continuous by changing the number of tapes. Furthermore, the use of NiTi material enables a temperature-dependent response. Due to the particular mounting, the flag-shaped pseudoelastic mechanical behavior typical of NiTi is partially hidden; however, the use of pseudoelastic elements provides a stable cyclic response and enables the possibility to tune the output torque.