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Verification and validation of multiscale fracture in ceramics by discretization and model adaptivity

通过离散化和模型自适应验证陶瓷多尺度断裂

基本信息

批准号：
117309069
负责人：
Professor Dr.-Ing. Peter Wriggers
金额：
--
依托单位：
Institut für Baumechanik und Numerische Mechanik (IBNM)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2009
资助国家：
德国
起止时间：
2008-12-31 至 2014-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/117309069?language=en
关键词：
Verification validation multiscale fracture ceramics

项目摘要

The error-controlled reliable prediction of 2D - and more important - for 3D microstructural crack initiation and propagation leading to macrocracks, their progression paths and eventually the failure of a structural component made of a brittle material (such as ceramics) is yet a widely unsolved problem. Since microcracks initiated in highly stressed domains of brittle materials usually have a size of the order of crystal grains shortly after their formation, the investigation of microcracks developing to macrocracks in a large scale structure clearly is a multiscale phenomenon and cannot be treated in a single scale numerical analysis. It also cannot be solved by using representative volume elements (RVEs). In this project we are going to develop goal-oriented error estimators for quantities of interest for combined model-and-discretization-adaptive multiscale numerical methods in order to predict crack initiation and progression in ceramics with prescribed error tolerances. In contrast to model reduction approaches, the adaptive modeling technique used for this project will be a model expansion approach from macro to meso (and micro) scale to allow for an efficient numerical treatment. Since numerical simulations of highly complex and changing geometries, such as advancing cracks, with standard finite element techniques are not favorable due to frequent remeshing, an adequate extended finite element method in combination with level set techniques will be developed in the coupled project by Dr.-Ing. Stefan Löhnert with the key word „multiscale XFEM . The computational model developed in this and in the coupled project will be validated by comparison of adaptive numerical results with experimental data, which will also be measured in the coupled project.

误差控制的可靠预测的2D -更重要的是-三维微观结构裂纹的萌生和扩展，导致宏观裂纹，其发展路径，并最终失败的结构部件制成的脆性材料（如陶瓷）仍然是一个广泛未解决的问题。由于在脆性材料的高应力域中产生的微裂纹通常在形成后不久就具有晶粒级的尺寸，因此在大尺度结构中微裂纹发展为宏观裂纹的研究显然是一个多尺度现象，不能在单尺度数值分析中处理。它也不能通过使用代表性体积元素（RVE）来解决。在这个项目中，我们将开发目标为导向的误差估计量相结合的模型和离散化自适应多尺度数值方法，以预测陶瓷裂纹的萌生和发展与规定的误差容限。与模型简化方法相比，本项目使用的自适应建模技术将是一种从宏观到中观（和微观）尺度的模型扩展方法，以实现有效的数值处理。由于数值模拟高度复杂和不断变化的几何形状，如前进的裂纹，与标准的有限元技术是不利的，由于频繁的重新网格化，一个适当的扩展有限元方法结合水平集技术将开发在耦合项目由博士。Ing. Stefan Löhnert的关键词是“多尺度XFEM”。在此和耦合项目中开发的计算模型将通过自适应数值结果与实验数据的比较进行验证，这些数据也将在耦合项目中进行测量。