Constitutive relationship and applications of shape-memory alloys

A constitutive relationship has been applied to study the behavior of structures and composites of the shape-memory alloy (SMA). The predictability of the constitutive relationship is confirmed by the uniaxial and multiaxial examples. The paper gives out the finite element algorithmic implementations, which is applied to implement as umat of ABAQUS. As two kinds of applications, CT (compact tensile) and TPB (three point bending) specimens and SMA-fiber enforced metal matrix and metal-fiber reinforced SMA-matrix composites are analyzed. The different distributions of martensite fraction of the CT specimens and TPB-specimens made of SMAs are explained by the different stress characteristics before the cracks. The study on the SMA-related composites shows that the bulk mechanic behavior depends on the volume of SMA and the non-SMA matrix/fiber properties.