Nucleation and Kinetics of Phase Boundaries in Peridynami

Kaushik Dayal
Carnegie Mellon University

Abstract: Active materials such as shape memory alloys display unusual and important coupling between deformation, temperature, and other physics. These unusual couplings result from structural transformations between different crystal phases. Classical continuum processes are not closed, and require nucleation and kinetic information as additional input. We examine this in peridynamics, a nonlocal integral continuum model. Our computational results suggest that kinetics is inherent to this theory. The perspective of nucleation as arising from dynamic instability leads to interesting results that are consistent with simulations (and not with the traditional view of nucleation). We also find an unusual mechanism for a phase boundary to bypass an inclusion in a shape memory alloy.

Joint work with Kaushik Bhattacharya. Appears in J. Mech. Phys. Solids, 54:1811, 2006 Offprint available at