Phase transformations and shape memory effects in finite length nanostructures

Melnik, R.V.N., Wang, L.X., Tsviliuk, O.I.

Proceedings SPIE, Behavior and Mechanics of Multifunctional Materials and Composites, Eds. Ounaies, Z. and Li, J., Vol. 7644,pp. 76440I-76440I-10, San Diego, USA,  2010

Abstract:

We discuss a relatively simple and computationally inexpensive model that has recently been developed to study phase transformations and shape memory effects in finite nanostructures. Our major focus is given to nanowires of finite length and other nanostructures where size effects are pronounced. The main tool used here is based on mesoscopic models developed with the phase-field approach which we and other authors have applied before to study ferroelectrics at the nanoscale. We study the cubic-to-tetragonal transformations in which case the 2D analogue of the model describes the square-to-rectangle phase transformations. The actual model is based on a coupled system of partial differential equations and is solved with a combination of the Chebyshev collocation method and the extended proper orthogonal decomposition. The developed model and its numerical implementation allow us to study properties of nanostructures and several representative examples of mechanical behavior of nanostructures are discussed.

Keywords:  finite length nanowires, low dimensional nanostructures, Chebyshev collocation, phase transformations, shape memory effects, coupled problems