• Meraghni, Fodil
• Zineb, Tarak Ben
• Collard, Christophe
• Bourgeois, Nadine
• Merzouki, Tarek

Abstract

This paper deals with the experimental and numerical analysis of the effect of stress-strain heterogeneities due to elastic anisotropy, grain orientations and their effects on martensitic transformation for a Cu-Based SMA multicrystal. The shape of each grain is measured successively by optical microscopy and Electron Back Scattered Diffraction technique. During a tensile loading at room temperature, the displacement field of the free surface is measured by Digital Image Correlation. The considered shape for the finite element analysis is designed on the basis of the experimental characterization of the shape of each grain. The model is intended to simulate the behaviour of the multicrystal. The experimentally obtained data, such as the actual applied boundary conditions at the edge of the area, crystallographic orientation, and some material parameters of the literature chosen to be in conformity with our case, are introduced in the numerical model designed by the Abaqus finite element code. A SMA micromechanical constitutive law, implemented in this FE code, is considered for the behaviour description of each grain. It describes the effect of a martensitic transformation on the behaviour of a single crystal by taking into account the possible activation of various martensite variants. The study shows that the experimental and numerical results are in good agreement. Moreover, numerical results show the stress state in grains is disturbed by the neighboring grains and this disturbance has a strong influence on the martensite variant activation.

Topics

• impedance spectroscopy
• surface
• single crystal
• grain
• experiment
• simulation
• activation
• optical microscopy
• finite element analysis