{ "id": "1205.3578", "version": "v2", "published": "2012-05-16T07:14:52.000Z", "updated": "2013-04-15T11:05:08.000Z", "title": "A degenerating PDE system for phase transitions and damage", "authors": [ "Elisabetta Rocca", "Riccarda Rossi" ], "categories": [ "math.AP" ], "abstract": "In this paper, we analyze a PDE system arising in the modeling of phase transition and damage phenomena in thermoviscoelastic materials. The resulting evolution equations in the unknowns \\theta (absolute temperature), u (displacement), and \\chi (phase/damage parameter) are strongly nonlinearly coupled. Moreover, the momentum equation for u contains \\chi-dependent elliptic operators, which degenerate at the pure phases (corresponding to the values \\chi=0 and \\chi=1), making the whole system degenerate. That is why, we have to resort to a suitable weak solvability notion for the analysis of the problem: it consists of the weak formulations of the heat and momentum equation, and, for the phase/damage parameter \\chi, of a generalization of the principle of virtual powers, partially mutuated from the theory of rate-independent damage processes. To prove an existence result for this weak formulation, an approximating problem is introduced, where the elliptic degeneracy of the displacement equation is ruled out: in the framework of damage models, this corresponds to allowing for partial damage only. For such an approximate system, global-in-time existence and well-posedness results are established in various cases. Then, the passage to the limit to the degenerate system is performed via suitable variational techniques.", "revisions": [ { "version": "v2", "updated": "2013-04-15T11:05:08.000Z" } ], "analyses": { "keywords": [ "degenerating pde system", "phase transition", "phase/damage parameter", "momentum equation", "weak formulation" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2012arXiv1205.3578R" } } }