H. Tobushi, T. Sakuragi, Y. Sugimoto, Aichi Institute of Technology, Toyot, Japan
If a shpae-memory alloy (SMA) thin strip is applied to the elements subjected torsion, a rotary driving element with a simple mechanism can be developed. In order to develop the rotary driving elements with SMA thin strip, the torsion test, the recovery torque test and torsional fatigue test were carried out for TiNi SMA thin strip. The basic characteristics for torsion of SMA thin strip were obtained. Torque increases in proportion to torsional angle and temperature. Recovery torque increases in proportion to torsional angle and temperature. Fatgue life decreases in proprtion to torsional angle. The fatigue life of the heat-treated material is longer than that of the as-received material. The fatigue limit of torisional angle of the heat-treated material is almost the same as that of the as-received material. In oerder to develop the rotary driving elements, an opening and closing door driven by SMA thin strip is demonstrated.
Summary: If the shape-memory alloy thin strip is applied to be subjected to torsional moment, the simple and compact rotary-driving SMA element can be developed. In the present study, the basic deformation properties of thin strip of TiNi SMA subjected to torsional moment were invested. The characteristics of recovery torque was also investigated. In applications of rotary driving elements, the fatigue properties are very important. In the present study, the fatigue properties of SMA thin strip subjected to cyclic torsional deformation were investigated. In order to develop the rotary driving elements, a model of opening and closing door was demontstrated.
