The nature of configurational forces

Abstract: "The standard forces associated with continua arise as a response to the motion of material points. That additional configurational forces may be needed to describe internal structure is clear from Eshelby's work on lattice defects. Eshelby's studies are statical, based on variational arguments. I take a different point of view. I believe that configurational forces should be viewed as basic objects consistent with their own force balance, rather than as variational constructs. My objective here is to demonstrate the power of configurational force balances in the study of dynamical phase transitions. In standard theories of Stefan-type solidification, curvature flows, and solid-solid phase transitions an extra interface condition -- over and above those that follow from standard balance laws -- is needed. What I believe to be a compelling argument in support of configurational forces is the conceptual unification that results: each of these 'extra' conditions is a consequence of the configurational balance applied across the interface. Configurational forces also lead to new results for existing theories (e.g., a weak formulation of the supercooled Stefan problem) and seem a valuable component in the formulation of new theories."