TY - JOUR A1 - Levkovitch, Vladislav A1 - Sievert, Rainer A1 - Svendsen, B. T1 - Application of extended crystal plasticity to the modeling of glide and kink bands and of crack opening in single crystals JF - Computational materials science N2 - In this work, the influence of the development of geometrically necessary dislocations (GNDs) at a crack tip in single crystals on the hardening and crack propagation behaviour is investigated. In particular, we are interested in examining the effect of such additional hardening on the development of glide and kink bands at the crack tip as well as on the process of crack opening. To this end, following Nye and many others, local deformation incompatibility in the material is adopted as a measure of the density of GNDs. Their development results in additional energy being stored in the material, leading to additional kinematic-like hardening. A thermodynamic formulation of the model in the context of the dissipation principle facilitates the derivation of the corresponding hardening relation. Results suggest that this additional hardening retards kink-band development, but has little or no influence on glide-band development. It also influences the crack tip opening displacement (CTOD). It turns out that the simulated CTOD correlates well with experimentally determined crack-propagation rates for different crack growth direction in the crystal. KW - Thermodynamics KW - Single crystal plasticity KW - Geometrically necessary dislocations KW - Hardening KW - Glide and kink bands KW - Crack-opening displacement PY - 2005 SN - 0927-0256 VL - 32 IS - 3-4 SP - 426 EP - 434 PB - Elsevier CY - Amsterdam AN - OPUS4-7067 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -