Adaptive probabilistic modeling of localization, failure and size effect of quasi-brittle materials

准脆性材料局部化、失效和尺寸效应的自适应概率建模

• 批准号: 5427935
• 负责人: Professor Dr.-Ing. Konstantin Meskouris
• 金额: --
• 依托单位: Lehrstuhl und Institut für Massivbau
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2004
• 资助国家: 德国
• 起止时间: 2003-12-31 至 2008-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5427935?language=en
• 关键词: Adaptive; probabilistic; modeling; localization; failure

In structural materials, the presence of fine-scale features with random nature can greatly affect material properties such as stiffness, ultimate strength and the size of the fracture process zone. Unfortunately, if all microscale interactions are minutely taken into account in the numerical analysis, even deterministically, computational models of enormous size and complexity typically emerge. In order to capture the damage process in the microstructure while keeping the complexity of the problem down to manageable levels, we propose to combine and utilize the advanced techniques of the adaptive finite element method and of random field simulations in an single model. The developed model will allow us to gradually zoom into the fine scale of the material structure with locally inctreased computational demand in critical regions only. In these areas, the heterogeneity of the material described by randomly fluctuating fields is essential for the development of microcracks, localization of deformation and the subsequent formation of macrocracks. This interdisciplinary approach employing methods of adaptivity and stochastics will allow us to capture the size effect phenomena in its complexity and to provide a computational tool for robust analysis and reliability assessment of large structures with quasi-brittle materials that is hitherto not possible with the currently available methods and tools...

在结构材料中，具有随机性质的细尺度特征的存在可以极大地影响材料特性，例如刚度、极限强度和断裂过程区的尺寸。不幸的是，如果在数值分析中详细考虑所有微尺度相互作用，即使是确定性的，通常会出现巨大规模和复杂性的计算模型。为了捕捉在微观结构中的损伤过程，同时保持问题的复杂性降低到可管理的水平，我们建议联合收割机，并利用先进的技术，自适应有限元法和随机场模拟在一个单一的模型。开发的模型将使我们能够逐渐放大材料结构的精细尺度，仅在关键区域局部增加计算需求。在这些领域中，由随机波动场描述的材料的不均匀性对于微裂纹的发展、变形的局部化以及随后的宏观裂纹的形成是必不可少的。这种跨学科的方法，采用自适应和随机的方法将使我们能够捕捉其复杂性的尺寸效应现象，并提供一个强大的分析和可靠性评估的大型结构与准脆性材料，迄今为止是不可能的计算工具与目前可用的方法和工具。