Automatic polyhedral mesh generation and adaptive analysis of fracture processes in brittle polycrystalline materials

脆性多晶材料断裂过程的自动多面体网格生成和自适应分析

• 批准号: 529593906
• 负责人: Professorin Dr.-Ing. Carolin Birk
• 金额: --
• 依托单位: Fachgebiet Statik und Dynamik der Tragwerke
• 依托单位国家: 德国
• 项目类别: Research Units
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/529593906?language=en
• 关键词: Automatic; polyhedral; mesh; generation; adaptive

The proposed project addresses the numerical modeling of both intergranular and transgranular fracture phenomena in brittle polycrystalline material. Such materials, e.g. solar grade silicon, are used in various engineering applications where accurate prediction of failure modes is imperative. A major objective of the project is to devise, implement and benchmark robust and automatic mesh generation and analysis techniques tailored to the specific requirements of fracture modelling in solids that are composed of randomly oriented polygonal or polyhedral regions. Here, challenges arise due to the fact that grain sizes may vary strongly in size, grain boundaries must be retained and fine meshes may be required near grain boundaries and in transgranular fracture zones. To this end, an integrated meshing, refinement and modeling approach will be developed in close cooperation with project partners who are experts in the field of geometrical modeling. In addition to adopting a hierarchical polytree approach to facilitate highly localized refinement we aim to develop an innovative alternative meshing approach that is based on increasing mesh density by shifting nodes while retaining the connectivity. Automated analyses on hierarchical meshes are facilitated by the scaled boundary finite element method (SBFEM), which can be used on arbitrarily faceted star-convex polygonal or polyhedral domains with hanging nodes. Taking into account the geometrical aspects explained above, we also aim to develop an adaptive framework for brittle fracture modeling where both intergranular and transgranular failure modes will be addressed. To this end, we strive to develop a scaled-boundary based multi-phase field approach for purely mechanical fracture in a first step and to extend the latter to multi-physical / thermally-induced fracture in a second step. Since the SBFEM in its original form has been derived for linear elasticity, we therefore aim to further develop the concept of polygonal / polyhedral shape functions based on SBFEM to solve multi-physical fracture problems. The final simulation framework will facilitate multi-physical brittle fracture modeling on complex polycrystalline geometries and will thus contribute to the greater objective of developing polytope element technology for the analysis of nonlinear problems in mechanics.

该项目旨在对脆性多晶材料的沿晶和穿晶断裂现象进行数值模拟。这种材料，例如太阳能级硅，用于各种工程应用中，其中准确预测故障模式是必要的。该项目的一个主要目标是设计，实施和基准测试的强大和自动网格生成和分析技术，专门针对由随机取向的多边形或多面体区域组成的固体断裂建模的具体要求。在这里，由于晶粒尺寸可能在尺寸上变化很大，必须保留晶界，并且在晶界附近和穿晶断裂带中可能需要细网格，因此出现了挑战。为此，将与几何建模领域的专家项目合作伙伴密切合作，开发一种集成的网格划分、细化和建模方法。除了采用层次多叉树的方法，以促进高度本地化的细化，我们的目标是开发一种创新的替代网格化方法，是基于增加网格密度的移动节点，同时保持连接。比例边界有限元法（SBFEM）可用于任意分面的星凸多边形或多面体区域上的悬挂节点，便于分层网格的自动分析。考虑到上述几何方面的解释，我们还旨在开发一个自适应框架的脆性断裂建模，其中晶间和穿晶失效模式将得到解决。为此，我们努力开发一个基于比例边界的多相场方法，在第一步中的纯机械断裂，并在第二步中将后者扩展到多物理/热致断裂。由于SBFEM在其原始形式已经推导出线弹性，因此，我们的目标是进一步发展的概念，多边形/多面体形状函数的基础上SBFEM解决多物理断裂问题。最终的模拟框架将有利于多物理脆性断裂建模复杂的多晶几何形状，从而有助于更大的目标，开发多面体元技术的非线性问题的分析力学。