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Simulation of diffusional processes from the microscopic and macroscopic point of view
Author(s) -
Ilic Sandra,
Hackl Klaus
Publication year - 2009
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.200910188
Subject(s) - homogenization (climate) , dissipation , creep , mechanics , materials science , grain boundary , statistical physics , boundary value problem , physics , thermodynamics , composite material , microstructure , biodiversity , ecology , quantum mechanics , biology
Within this contribution, the modeling of diffusional processes will be elucidated by the example of solution‐precipitation creep. This deformation process occurs in polycrystalline and granular materials exposed to high temperatures and moderate stresses. The presence of water facilitating the material transport in the intercrystalline space especially intensifies the process. The continuum‐micromechanical model presented here considers the velocities of the material transport and the grain‐boundary motion caused in this way to be the main contributions to the dissipation term characteristic for this process. Simulating the real macrostructures in addition requires coupling with homogenization techniques. To this end, our particular choice pertains to the multiscale FE method with the advantages that it is adapted to the case of finite deformations and that it is applicable in the limit case when the ratio of the characteristic lengths of the micro‐ and macroscale tends to zero. As a final result, application of the mentioned method gives information on the time dependency of macroscopic deformations. (© 2009 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)