Experimental bench for shape memory alloys actuators design and testing

摘要

Shape memory alloys (SMAs) are used as active elements in novel actuation devices. Two generic types of SMA actuators can be distinguished according to the type of bias passive-bias actuators where an elastic component serves as a bias and active-bias actuators where two SMA elements are connected together. This paper describes an experimental testing bench developed for the characterization of SMA active elements and their testing in a real actuation environment. The characterization of SMA active elements is performed under three complementary testing modes: (a) constant-stress, (b) fixed-support, and (c) elastic-bias recovery modes. Force, displacement and temperature data acquired during testing of a given SMA active element are then used to assess the mechanical work-generation potential of this active element and, ultimately, for the design of an SMA actuator containing this element. Finally, a case study is presented to illustrate the experimental design methodology and results.