Temperature and grain size effects on the behavior of CuAlBe SMA wires under cyclic loading

Abstract

This study evaluates the properties of a superelastic CuAlBe shape memory alloy under cyclic loading to assess its potential for applications in seismic resistant design. Wires phi = 0.5 mm, previously heated during different periods of time, are tested to study the effect of grain size, temperature and strain rate on the strength, equivalent viscous damping, and recentering properties of the alloy. The wires are subjected to quasi-static and dynamic tensile loading tests. The results show that nearly ideal superelastic properties can be obtained up to 3% axial strain. Overall, the damping potential of the alloy is moderate, typically less than 5%. Increased temperatures lead to a reduction in the equivalent damping and an increase in the forward transformation stress, and increased grain sizes lead to an increase in the equivalent damping and a reduction in the forward transformation and ultimate stresses.