A boundary element application for mixed modeloading idealized sawtooth fracture surface

In this paper\ a 1!D elastic!plastic BEM formulation predicting the reduced mode II and the enhanced mode I stress intensity factors are presented[ The dilatant boundary conditions "DBC# are assumed to be idealized uniform sawtooth crack surfaces and an e}ective Coulomb sliding law[ Three types of crack face boundary conditions\ i[e[ "0# BEM sawtooth model!elastic center crack tip^ "1# BEM sawtooth model!plastic center crack tip^ and "2# BEM sawtooth model!edge crack with asperity wear are presented[ The model is developed to attempt to describe experimentally observed non!monotonic\ non!linear dependence of shear crack behavior on applied shear stress\ superimposed tensile stress\ and crack length[ The asperity sliding is governed by Coulomb|s law of friction applied on the inclined asperity surface which has coe.cient of friction m[ The traction and displacement Green|s functions which derive from Navier|s equations are obtained as well as the governing boundary integral equations for an in_nite elastic medium[ Accuracy test is performed by comparison stress intensity factors of the BEM model with analytical solutions of the elastic center crack tip[ The numerical results show the potential application of the BEM model to investigate the e}ect of mixed mode loading problems with various boundary conditions and physical interactions