Karine Taillard

Relation between martensite volume fraction and equivalent transformation strain in an anisotropic CuAIBe shape memory alloy

This study concerns the pseudoelasticity of Shape Memory Alloys (SMA). A series of tests under tension-compression-torsion multiaxial loadings is used to show the validity of a conjecture concerning the relation between the volume fraction of martensite and the equivalent transformation strain. It is shown that the proportionality between an ad doc equivalent transformation strain and the volume fraction of martensite is confirmed under multiaxial proportional and nonproportional loadings.

Multiaxial One Way Shape Memory Effect and Superelasticity

The specific behaviour of Shape Memory Alloys (SMA) is due to a solid-solid transformation called martensitic transformation [1]. This reversible transformation consists mainly in a shear without volume change and is activated either by stress or temperature. This partition between austenite (high temperature phase) and martensite (low temperature phase) is responsible for the specific properties of SMA: the superelastic behaviour (isothermal) and the one way shape memory effect (non-isothermal).