Analysis of void growth in a ductile material in front of a crack tip

The growth of microvoids in a ductile material is analysed in front of a crack tip loaded by a remote KI field. For this purpose, a circular region with radius R around the crack tip containing statistically distributed initially circular microvoids of radii r is discretised. The material behaviour is described by classical J2 plasticity with power hardening law in the scope of finite deformations. The process region is subdivided into a patch of randomly generated polygons simulating a real crystallic microstructure with a characteristic length scale. Within these polygons the material behaviour is represented by the identical, above-mentioned assumptions and constitutive model but with a statistical deviation from their average values. The second part focuses on the representation of geometrically necessary dislocations in the context of the applied finite strain description within the FE formulation. The aim of this investigation is a deeper understanding of correlations between material and geometrical properties of mode I dominated ductile damage and failure processes. Results of the parameter studies show strain distributions around typical microvoids and along the ligament.