Effect of change in coil orientation for SMA spring

Abstract

This work is concerned with fabrication of SMA coil spring which shows perfect recovery despite slip deformation by using the 'initial tension'. We have developed a new method of providing the initial tension to SMA springs by changing coil orientation after the shape setting treatment. In this paper, some examples are introduced that a perfect recovery with a greater force, though permanent deformation is involved in the deformation, can be attained by the initial tension. Besides generation of two way shape memory effect is presented using the reverse of coil orientation. (C) 20111 Elsevier B.V. All rights reserved.