A strain gradient plasticity model of porous single crystal ductile fracture

A strain gradient void-driven ductile fracture model of single crystals is proposed and applied to simulate crack propagation in oligo-crystal specimens. The based on a thermodynamical framework for homogenized porous solids unifying generalizing existing formulations. This crystal relies multi-surface representation plasticity which the standard Schmid law enhanced account porosity, including void growth coalescence mechanisms. new criterion detect onset validated by comparison unit-cell simulations. can either be used as an additional yield surface or it follow well established Gurson–Tvergaard–Needleman approach effective porosity coalescence. formulation Lagrange multiplier relaxation plasticity. Material points simulations are performed order depict elementary features without effects. then simulation plane specimen loaded tension up failure. regularization ability convergence with mesh refinement demonstrated. Finally two- three-dimensional specimens presented. significant influence plastic anisotropy path, ductility toughness highlighted.