Numerical simulations of the pseudoelastic effect in CuZnAl shape-memory single crystals considering two successive martensitic transitions

Abstract

Shape memory alloys (SMAs) with double martensitic transitions are potential candidates for highly effective, nonstandard mechanical damping systems. This paper presents a numerical model that can be used to simulate pseudoelasticity in systems with two successive martensitic transformations, such as adequately oriented CuZnAl, CuAlNi and CuAlBe single crystals. The model is based on stress versus strain data obtained from the tensile test of a CuZnAl single crystal and is able to simulate the mechanical damping of SMAs with two successive martensitic transitions. The numerical model has been implemented as an algorithm and used to assess the mechanical damping capacity of a system based on CuZnAl SMA single crystals, considering the complete β-18R-6R cycle. A numerical model with a single degree of freedom is used and the behavior of the SMA-based damper is analyzed both under free and forced oscillation conditions. The results obtained indicate that the alloy studied is a very effective mechanical damper.