Adherence of Two Elastic Solids in Contact

Laboratoire des Materiaux et Structures (UMR 113), CNRS-LCPC, 75732 Paris Cedex 15, 

The energy of the system U = (7(5,83) is a function of the extensive variables S (entropy), 8, suid A it can be decomposed into elastic energy and interface energy = —wA. The first differential of the energy can be written in the form 

Quantity G, which describes the variation of elastic energy with A at constant 8, is the strain energy release rate. We note that hA is a kind of potential energy which can be recovered by crack healing. The three relationships 

By noting that Pb is the potential energy Up of the load, these expressions show that 

The Maxwell relations (obtained from the equality of the mixed partial derivatives of q or F) give 

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