Micromechanics of precipitated near-equiatomic Ni-rich NiTi shape memory alloys
- 330 Downloads
The specific thermo-mechanical behavior of precipitated, near-equiatomic Ni-rich NiTi shape memory alloys, i.e., thermal actuation under stress and pseudoelasticity, are investigated via the finite element method. The deformation response of the material-at-large is simulated using a representative volume element, taking into account the structural effect of the precipitates, as well as the effect of the Ni-concentration gradient in the matrix. An existing rate-independent constitutive model, similar to the one employed to describe the matrix behavior, is calibrated based on the deformation response of the representative volume elements. The actuation and pseudoelastic response of the homogenized material are found to be very close to those of the representative volume elements. The obtained results reproduce and provide important insight into several of the experimentally observed precipitation-induced changes on the transformation characteristics of these materials.
Unable to display preview. Download preview PDF.
- 1.Abaqus: Analysis User’s Manual. Dassault Systèmes of America Corp., Woodlands Hills, CA (2009)Google Scholar
- 2.Azadi B., Rajapakse R.K.N.D., Maijer D.M.: One-dimensional thermomechanical model for dynamic pseudoelastic response of shape memory alloys. Smart Mater. Struct. 15, 429–442 (2003)Google Scholar
- 17.Hartl, D.J., Lagoudas D.C.: Aerospace applications of shape memory alloys. In: Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering. SAGE, pp. 535–552 (2007)Google Scholar
- 22.Khalil-Allafi, J., Dlouhy, A., Eggeler, G.: Ni4Ti3-precipitation during aging of NiTi shape memory alloys and its influence on martensitic phase transformations. Acta Mater. 50, 4255–4274 (2002)Google Scholar
- 25.Lagoudas, D.C. (eds): Shape Memory Alloys: Modelling and Engineering Applications. Springer, New-York (2008)Google Scholar
- 27.Lejeunes, S., Bourgeois, S.: Abaqus plugins for generating boundary conditions for homogenization problems (2010)Google Scholar
- 41.Tanaka K., Mori T.: Average stress in matrix and average elastic energy of materials with misfitting inclusions. Acta Metall. Mater. 21, 571–574 (1970)Google Scholar