Density dependence of the superelastic behavior of porous shape memory alloys: Representative Volume Element and scaling relation approaches

As the use of Shape Memory Alloys (SMAs) grows increasingly common in many industrial applications, the porous form of SMA is of particular interest as it associates both the shape memory effect and superelasticity with the characteristics of foam. However, numerical prediction of the mechanical response of SMA foam is very challenging due to the micro-macro nature exhibited by the material, as the porous microstructure is several orders of magnitude smaller than the overall dimensions of the macroscopic porous sample. To circumvent, or at least alleviate this computational weight, an attempt is made to describe the superelastic behavior of SMA foams using two approaches: Representative Volume Element (RVE) and scaling relation; the latter is based on modeling the fully-dense material with mechanical properties equivalent to those of its porous counterpart. This approach avoids direct modeling of the porous microstructure and thus contributes to a drastic reduction of the computational cost. A validation is made by comparing the numerical results obtained in this study with experimental results taken from the literature.