Three-dimensional analyses of ductile failure in metal reinforced by staggered fibres

Ductile matrix failure in a metal reinforced by short parallel fibres is st udied numerically in terms of full three-dimensional cell model analyses. T he model is extended here, relative to the simplest possible cell, such tha t transversely staggered fibres are accounted for and such that effects of different sizes of two neighbouring fibres can be studied. The matrix mater ial is described in terms of a porous ductile material model, which account s for the nucleation and growth of voids to coalescence. Most predictions a re based on an isotropic hardening model, but results for kinematic hardeni ng are used to study the effect of a metal that forms a rounded vertex on t he yield surface. The damage evolution tends to first show the formation of an open crack near the ends of the longer fibres, by void coalescence in t he matrix, and subsequently a similar crack evolves near the ends of the sh orter fibres.