混凝土细观损伤模拟与数值尺寸效应研究

项目名称： 混凝土细观损伤模拟与数值尺寸效应研究

项目编号： No.51208374

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 建筑环境与结构工程学科

项目作者： 任晓丹

作者单位： 同济大学

项目金额： 25万元

中文摘要： 在混凝土细观随机结构实验观测的基础上，深入研究混凝土细观结构的组成特点，建立合理的混凝土细观结构的描述方法；在此基础上，基于固体计算力学最新发展的细观模拟方法，精细模拟混凝土细观裂缝群的产生和发展过程，研究混凝土细观应力随机重分布规律；基于多尺度理论，选取合适的状态变量作为尺度间的桥梁，从细观数值模拟结果出发求解宏观损伤随机演化规律，并与多维连续损伤模型相结合，构成多尺度随机损伤模型的完整体系；采用所建立的多尺度随机损伤模型模拟混凝土结构的全过程非线性行为，有针对性地探索尺寸效应等传统结构非线性分析难以处理的问题，为结构非线性分析与设计提供理论工具与技术支持。

中文关键词： 混凝土；损伤；多尺度；随机场；动力灾变

英文摘要： The constitutive law of concrete defines the functional relation between stress and strain and plays a fundamental role in the analysis of structures. However, except for several remarkable progresses, the constitutive modeling and nonlinear analysis of concrete structures still remain quite challenging. In recent 20 years, the rapid developments of damage mechanics, computational solid mechanics and multi-scale theories lead to a paradigm shifting for the constitutive modeling of concrete and lay a solid foundation for the proposed investigation. Based on the systematic experimental observations, the mesoscopic random structure of concrete is investigated and modeled with appropriate numerical descriptions. Then by introducing the newest mesoscopic methods of computational solid mechanics, the stochastic propagation of the mesoscopic crack group could be simulated accurately. To solve the stochastic damage evolution in the macro-scale, the bridging vehicle spanning between the mesoscopic crack propagation and the macroscopic damage evolution is investigated based on classic homogenization theory, while the multi-scale stochastic damage model could be established with the stochastic damage evolutions informed from the meso-scale. Based on the proposed model, the nonlinear behaviors of concrete structures are num

英文关键词： concrete；damage；multi-scale；random field；collapse