Effects of nonlocal damage in porous plastic solids

Abstract A nonlocal constitutive formulation for a porous ductile material is investigated, in which delocalization relates to the damage mechanism. An elastic-viscoplastic material model is used, with delocalization incorporated in terms of an integral condition on the rate of increase of the void volume fraction. Two model problems are analysed to study the effect of including this material length, one relates to localization of plastic flow in shear bands, while the other considers a metal matrix composite. Both model problems involve final failure in strongly nonhomogeneous strain fields, and it is shown that the inherent mesh sensitivity of the numerical failure predictions can be removed by using the nonlocal material model considered here.

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