A variable stiffness joint with superelastic material

The aim of this paper is to provide the design of a variable stiffness joint able to perform large rotations without undergoing plastic strain. The joint comprises two leaf springs of variable length, allowing to adjust the stiffness of the joint according to the desired performance. Large rotations are achieved by employing superelastic material for the leaf springs, instead of common linear elastic material. The behaviour of the joint has been investigated by means of finite element analyses; in addition, the first attempt to develop a simple mathematical model for the superelastic material as alternative to finite element method is described.