Simulation of the effect of elastic precipitates in SMA materials based on a micromechanical model

摘要

This paper deals with the modeling of Shape Memory Alloys (SMA) with embedded precipitates, and describes the effect of these precipitates on the phase transformation properties. It is based on a micro-mechanical constitutive model and uses a double scale transition technique. The first scale transition considers elastic inclusions embedded in an SMA matrix. It uses the Mori-Tanaka homogenization technique to determine the equivalent behavior of an SMA single crystal. The second scale transition leads to the effective behavior of an SMA polycrystalline aggregate. It is based on the behavior of each grain and uses a self-consistent homogenization technique. The constitutive non-linear equations of this model are then numerically solved. The results obtained under different loadings are detailed and discussed at the grain and at the sample (macroscopic) scales. Finally the effect of the volume fraction of precipitates on the transformation properties are discussed.