Multiscale modeling and extended finite element analysis of fracture processes in ceramics

陶瓷断裂过程的多尺度建模和扩展有限元分析

• 批准号: 117343076
• 负责人: Professor Dr.-Ing. Stefan Löhnert
• 金额: --
• 依托单位: Institut für Kontinuumsmechanik (IKM)
• 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 2013-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/117343076?language=en
• 关键词: Multiscale; modeling; extended; finite; element

The reliable prediction of three dimensional microstructural crack initiation and propagation leading to macrocracks and eventually the failure of a structure is yet an unsolved problem. Since microcracks which initiate in highly stressed domains in ceramics usually have a size of the order of the micro constituents 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. In this project we develop an adaptive multiscale method for the accurate prediction of crack initiation and development in ceramics. The adaptive modeling technique used for this project will be a model expansion approach for areas of interest in order to make a numerical treatment feasible. The goal-oriented error estimators for quantities of interest for the combined model and discretization adaptive multiscale numerical method will be developed in the joint project by Prof. Dr.-Ing. Peter Wriggers and Prof. em. Dr.-Ing Dr.-Ing E.h. Dr h.c. mult. Erwin Stein with the key word “multiscale adaptivity”. Since the numerical simulation of highly complex and changing geometries such as advancing cracks using standard finite element techniques is not favorable due to the frequent need of remeshing, we employ the extended finite element method in combination with level set techniques to describe the geometry and to simulate propagating cracks. The computational model developed in this project will be validated by comparison of numerical results to experimental data.

如何可靠地预测三维微结构裂纹的萌生和扩展，导致宏观裂纹并最终导致结构的失效，仍是一个悬而未决的问题。由于在陶瓷高应力区产生的微裂纹通常在形成后不久就具有微观成分量级的尺寸，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，不能用单一尺度的数值分析来处理。在这个项目中，我们开发了一种自适应多尺度方法来准确预测陶瓷中裂纹的萌生和发展。该项目使用的自适应建模技术将是对感兴趣区域的模型扩展方法，以便使数值处理可行。该联合模型的目标导向误差估计器和离散化自适应多尺度数值方法将由Dr.-ing教授共同开发。彼得·瑞格斯和艾姆教授。博士-E.H.H.c博士。莫特。欧文·斯坦以“多尺度适应性”为关键词。由于采用标准有限元技术对复杂多变的几何形状进行数值模拟，如裂纹扩展，需要频繁地重新划分网格，因此我们采用扩展有限元方法并结合Level Set技术来描述几何形状和模拟裂纹扩展。本项目所建立的计算模型将通过数值计算结果与实验数据的比较来验证。