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.

对 2D（更重要的是）3D 微观结构裂纹萌生和扩展导致宏观裂纹、它们的进展路径以及最终由脆性材料（例如陶瓷）制成的结构部件失效的误差控制可靠预测仍然是一个广泛未解决的问题由于脆性材料的高应力区域中引发的微裂纹通常在形成后不久就具有晶粒的尺寸，因此对大尺度结构中微裂纹发展为宏观裂纹的研究显然是一个难题。多尺度现象，不能在单尺度数值分析中处理，也不能通过使用代表性体积元素（RVE）来解决。在这个项目中，我们将开发面向目标的误差估计器，用于组合模型和相关的数量。离散化自适应多尺度数值方法，用于预测具有规定误差容限的陶瓷中的裂纹萌生和进展。与模型简化方法相比，该项目使用的自适应建模技术将是从宏观到细观（和微观）的模型扩展方法。）规模以允许由于频繁重新网格化，高度复杂且不断变化的几何形状（例如推进裂纹）的数值模拟并不有利，因此将在本研究中开发与水平集技术相结合的适当扩展有限元方法。 Stefan Löhnert 博士的耦合项目，其关键词是“多尺度 XFEM”。在此项目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，实验数据也将在耦合项目。