TY - JOUR A1 - Forest, S. A1 - Sievert, Rainer A1 - Aifantis, E. C. T1 - Strain gradient crystal plasticity: Thermomechanical formulations and applications JF - Journal of the mechanical behavior of materials PY - 2002 SN - 0334-8938 VL - 13 IS - 3-4 SP - 219 EP - 232 PB - Freund Publ. CY - London AN - OPUS4-2858 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Forest, S. A1 - Boubidi, Pascal A1 - Sievert, Rainer T1 - Strain Localization Patterns at a Crack Tip in Generalized Single Crystal Plasticity JF - Scripta materialia KW - Crack KW - Single crystal KW - Crystal plasticity KW - Cosserat medium KW - Strain localization PY - 2001 DO - https://doi.org/10.1016/S1359-6462(00)00684-9 SN - 1359-6462 SN - 1872-8456 VL - 44 IS - 6 SP - 953 EP - 958 PB - Elsevier CY - Oxford AN - OPUS4-3972 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Forest, S. A1 - Sievert, Rainer T1 - Nonlinear microstrain theories JF - International journal of solids and structures N2 - A hierarchy of higher order continua is presented that introduces additional degrees of freedom accounting for volume changes, rotation and straining of an underlying microstructure. An increase in the number of degrees of freedom represents a refinement of the material description. In addition to available nonlinear Cosserat and micromorphic theories, general formulations of elastoviscoplastic behaviour are proposed for microdilatation and microstretch continua. A microstrain theory is introduced that is based on six additional degrees of freedom describing the pure straining of the microstructural element. In each case, balance equations and boundary conditions are derived, decompositions of the finite strain measures into elastic and plastic parts are provided. The formulation of finite deformation elastoviscoplastic constitutive equations relies on the introduction of the free energy and dissipation potentials, thus complying with requirements of continuum thermodynamics. Some guidelines for the selection of a suitable higher order model for a given material close the discussion. KW - Continuum mechanics KW - Higher order continua KW - Micromorphic KW - Cosserat KW - Elastoviscoplasticity KW - Finite deformation PY - 2006 DO - https://doi.org/10.1016/j.ijsolstr.2006.05.012 SN - 0020-7683 VL - 43 IS - 24 SP - 7224 EP - 7245 PB - Elsevier CY - New York, NY AN - OPUS4-13734 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pinomaa, T. A1 - Lindroos, M. A1 - Jreidini, P. A1 - Haapalehto, M. A1 - Ammar, K. A1 - Wang, Lei A1 - Forest, S. A1 - Provatas, N. A1 - Laukkanen, A. T1 - Multiscale analysis of crystalline defect formation in rapid solidification of pure aluminium and aluminium-copper alloys JF - Philosophical transactions of the Royal Society - Series A N2 - Rapid solidification leads to unique microstructural features, where a less studied topic is the formation of various crystalline defects, including high dislocation densities, as well as gradients and splitting of the crystalline orientation. As these defects critically affect the material’s mechanical properties and performance features, it is important to understand the defect formation mechanisms, and how they depend on the solidification conditions and alloying. To illuminate the formation mechanisms of the rapid solidification induced crystalline defects, we conduct a multiscale modelling analysis consisting of bond-order potential-based molecular dynamics (MD), phase field crystal-based amplitude expansion simulations, and sequentially coupled phase field–crystal plasticity simulations. The resulting dislocation densities are quantified and compared to past experiments. The atomistic approaches (MD, PFC) can be used to calibrate continuum level crystal plasticity models, and the framework adds mechanistic insights arising from the multiscale analysis. This article is part of the theme issue ‘Transport phenomena in complex systems (part 2)’. KW - Rapid solidification KW - Crystalline defects KW - Molecular dynamics KW - Phase field crystal KW - Phase field method KW - Crystal plasticity PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542156 DO - https://doi.org/10.1098/rsta.2020.0319 SN - 1364-503X VL - 380 IS - 2217 SP - 1 EP - 20 PB - Royal Society CY - London AN - OPUS4-54215 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -