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.

对于3D微观结构裂纹的倡议和传播，误差控制的2D可靠预测导致了宏观裂纹，它们的进展路径以及最终是由脆性材料（例如陶瓷）制成的结构成分的失败是一个广泛的固定问题。由于在脆性材料的高应力结构域中启动的微裂料通常在形成后不久就具有晶体晶粒的大小，因此对大规模结构中向宏cracks开发的微裂纹的研究显然是多尺度现象，并且不能在单个尺度的数值分析中进行治疗。也不能通过使用代表量元素（RVE）来解决它。在这个项目中，我们将开发面向目标的误差估计量，以用于组合模型和自发性自适应多尺度数值方法的兴趣量，以预测具有处方误差的陶瓷的破解启动和进展。与模型还原方法相反，该项目使用的自适应建模技术将是从宏到中索（和微型）量表的模型扩展方法，以允许有效的数值处理。由于对高度复杂和变化的几何形状（例如前进的裂纹）的数值模拟，并且由于经常进行的标准有限元技术不利，因此将在博士的耦合项目中开发出适当的有限元方法与级别集合技术结合使用。 StefanLöhnert具有关键词„多尺度XFEM。在此和耦合项目中开发的计算模型将通过比较自适应数值结果与实验数据的比较来验证，这也将在耦合项目中进行测量。