On the formation of martensite in front of cracks in pseudoelastic shape memory alloys

摘要

In the present study we use finite element stress and strain analysis to study the stress induced martensitic transformations near the crack of compact tension (CT) specimens of pseudoelastic NiTi shape memory alloys. For this purpose, Aurichio's model for pseudoelasticity s implemented into the finite element code ABAQUS. The material parameters required in the model were adjusted according to load-/unloading data from pull-pull tests on pseudoelastic NiTi wires. Stress induced martensite forms near the notch of a CT specimen with pre-crack. The presence of a sharp pre-crack alters the results considerably. The results presented in this paper provide some guidance for interpretation of fracture mechanics tests on pseudoelastic shape memory alloys.