Micromechanical finite element analysis of metal matrix composites using nonlocal ductile failure models

Finite element studies of ductile damage in the matrix of particle and fiber reinforced metal matrix composites are presented. Three material models capable of supporting such simulations at the constituent level are discussed within a unified framework. They comprise an element removal technique triggered by a ductile damage indicator as well as versions of the ductile rupture models of Gurson and Rousselier. Nonlocal averaging is employed for reducing the mesh dependence typically displayed by continuum damage methods upon the onset of local softening. Implementation issues specific to the use of nonlocal damage models in a continuum micromechanics framework are discussed.The efficacy of the approach in limiting the mesh sensitivity of the predicted behavior of composites subject to matrix damage is demonstrated for a simple three-dimensional matrix-particle configuration. Applications of the method to multi-particle and multi-fiber unit cells subjected to uniaxial tensile loads are presented and effects of microgeometrical parameters on the mechanical response are discussed.