IMA Journal of Applied Mathematics Advance Access originally published online on August 24, 2006
IMA Journal of Applied Mathematics 2006 71(5):635-657; doi:10.1093/imamat/hxl014
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Primaldual methods of shape sensitivity analysis for curvilinear cracks with nonpenetration
Lavrent'ev Institute of Hydrodynamics, 630090 Novosibirsk, Russia and Institute for Mathematics, University of Graz, 8010 Graz, Austria
** Email: kovtunen{at}kfunigraz.ac.at
Based on a level-set description of a crack moving with a given velocity, the problem of shape perturb-ation of the crack is considered. Nonpenetration conditions are imposed between opposite crack surfaces which result in a constrained minimization problem describing equilibrium of a solid with the crack. We suggest a minimax formulation of the state problem thus allowing curvilinear (nonplanar) cracks for the consideration. Utilizing primaldual methods of shape sensitivity analysis we obtain the general formula for a shape derivative of the potential energy, which describes an energy-release rate for the curvilinear cracks. The conditions sufficient to rewrite it in the form of a path-independent integral (J-integral) are derived.
Keywords: curvilinear crack; nonpenetration; energy release; constrained minimization; shape sensitivity analysis; primaldual methods.
Received on 12 August 2004. accepted on 20 July 2005.