Shape Memory Alloy in Tension and Compression and its Application as Clamping-Force Actuator in a Bolted Joint: Part 1 — Experimentation

Abstract

In recent years, there have been some endeavors in order to characterize and model Shape Memory Alloy (SMA) behavior both in tension and compression. However, the one-dimensional behavior of SMA has been mostly studied for the case of wire elements subjected to tension. The objective of this paper is to analyze the behavior of Ni-55.7% wt Ti SMA in tension, compression, and at various temperatures. The effects of cycling, annealing, and friction on the mechanical behavior of this material in compression are discussed as well and, where applicable, compared to those of tension. The compressed SMA rings are finally used as clamping-force actuators in loosed bolted joints. In the second part of this paper, the experimental findings are compared with the theoretical counterparts.