Kinetics and nucleation of phase boundaries

                                   by

               Lev Truskinovsky,  University of Minnesota

                 JWB 333,  1:10pm Tuesday, May 7, 1996

                                Abstract

  In spite of a recent progress in our understanding of the absolute
  stability of elastic phases under applied loads, the presence of
  metastable configurations which is apparently a generic phenomenon,
  remains a major puzzle. In this talk, by considering most elementary
  one dimensional model of martensitic transformation, we address the
  question of the critical perturbation which breaks metastability. We
  shall first consider several alternative ways to regularize the
  elasticity equations for materials supporting several phases and try
  to justify them from the point of view of the prototypical discrete
  model of elastically interacting particles. This brings internal
  structure to sharp interfaces simulating phase boundaries, specifies
  the mechanism of dissipation and allows us to obtain the kinetic
  relation closing the original system of equations. We then interpret
  nucleation in terms of an instability of the regularized system with
  respect to finite perturbations.  This suggests that the nucleation
  criterion can be formulated in terms of the intensity of the
  perturbations and the prescribed "level of noise" in the system.


 Lev Truskinovsky
 Department of Aerospace Engineering and Mechanics
 University of Minnesota
 Minneapolis, MN 55455, USA

Requests for preprints and reprints to: trusk@aem.umn.edu
This source can be found at http://www.math.utah.edu/research/