A computational framework for microstructure evolution in metallic polycrystals is achieved by coupling large deformation Cosserat isotropic hyperelasticity with a phase-field model to take into account grain boundary formation and motion. Each material point has an associated crystal lattice orientation described by the Cosserat microrotation, which can evolve due to deformation or grain boundary migration. The analysis is restricted to transformations in the solid state. The numerical treatment of the proposed model requires some consideration. Discretization by finite elements leads to a strongly nonlinear, coupled system. The microrotation is parametrized to facilitate the numerical treatment of incremental updates of the Cosserat degrees of freedom. In order to reduce computation time and effort, a parallel computing mechanism based on domain decomposition is adopted together with an iterative staggered scheme to avoid the ill-conditioning inherent to the monolithic coupled system of equations.

中文翻译：

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通过 3D 有限应变 Cosserat 相场模型对微观结构演变进行基于有限元的仿真


通过将大变形 Cosserat 各向同性超弹性与相场模型耦合以考虑晶界形成和运动，实现了金属多晶微观结构演变的计算框架。每个材料点都有一个由 Cosserat 微旋转描述的相关晶格取向，该取向可能由于变形或晶界迁移而演变。分析仅限于固态中的转换。所提出的模型的数值处理需要考虑一些。有限元的离散化会导致强非线性耦合系统。对微旋转进行参数化，以便于 Cosserat 自由度增量更新的数值处理。为了减少计算时间和精力，采用基于域分解的并行计算机制和迭代交错方案，以避免单片耦合方程组固有的不良条件。