模拟混凝土破坏过程的微裂纹模型及其应用  

Micro-crack model for concrete rupture modeling and its applications

作　　者：吴佰建[1] 李兆霞[1] 郭力[1] 

机构地区：[1]东南大学土木工程学院,南京210096

出　　处：《东南大学学报（自然科学版）》2013年第5期1034-1038,共5页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(11072060)

摘　　要：提出了一种适用于定量模拟混凝土材料的微细观裂纹数值模型.该模型可用于模拟和分析材料破坏的全过程,包括砂浆/粗骨料界面上初始微裂纹的扩展、微裂纹的聚合、宏观主裂纹的形成与扩展及最终破裂的全过程.作为分析实例,对4组不同配比的16种混凝土拉伸试样进行了破坏过程仿真分析.结果表明,利用该数值模型可揭示混凝土常见的拉伸破坏模式与机理;骨料体积增加时,混凝土的延展性有增大趋势,强度则呈现减小趋势,这与已有文献中混凝土拉伸实验结果相符.该数值模型直接从失效机理出发,建立了定量描述含微细观裂纹的准脆性材料破坏过程的新方法,可望为该类材料/结构的失效控制或安全设计提供参考.A meso-scale multiple-crack model for modeling concrete rupture is proposed. This model can simulate the whole process of material rupture, including the growth of initial cracks on mortar/ aggregate interfaces, coalescence of cracks, formulation and growth of macro cracks, and the final concrete rupture. As applications, 16 specimens for 4 different concrete mixes are generated and calculated. Results show that the numerical model can be used for revealing common failure modes and mechanisms, the increase of aggregate volume fraction can improve concrete ductility, while at the same time, lower its strength, which coincides with existing experimental results. The model provides a new approach for numerically modeling the failure process of quasi-brittle materials. Since it is directly from the actual physics of concrete ruptures, hopefully this model can be utilized as an effective tool for failure control and safety design on concrete materials/structures.

关 键 词：准脆性材料 混凝土 数值模型 微细观裂纹 裂纹聚合 

分 类 号：O346.1[理学—固体力学]