混凝土结构裂缝萌生开展的扩展有限元分析

发布时间：2018-02-16 19:23

本文关键词： 粘性单元 Matlab ABAQUS 扩展有限元裂缝扩展　出处：《重庆交通大学》2014年硕士论文　论文类型：学位论文

【摘要】：在钢筋-混凝土结构的有限元分析中，构件的裂纹处理一直是该领域研究的热点和难点。本文在分析总结扩展有限元理论的基础上，依托周志祥教授所承担的交通运输部建设科技项目“SWFC复合结构在西藏地区连续刚构桥中的应用研究”展开以下主要研究工作： ①在归纳总结扩展有限元现有研究成果的基础上，推导了以应力强度因子为未知量的裂尖应力表达式，，利用单位分解法把裂尖富集函数内插到标准形函数中，得到了新的形函数的矩阵表达。 ②基于ABAQUS扩展有限元的原理，以Matlab为平台，依据极限应变率扩展准则和改进的极限应变率扩展准则，针对裂尖富集函数的实现，编写了扩展有限元分析程序。编写的扩展有限元程序，不仅了考虑了已开裂单元的富集函数，而且应用裂尖富集函数，更准确的描述了裂尖渐进场，精确地追踪了裂缝尖端的应力的改变。该程序同时使用子三角形法进行裂尖网格密度重加密，运用水平集函数进行裂纹扩展路径的表示。 ③运用Matlab-XFEM程序对无穷板中边裂纹、板内多角度裂纹的静止状态和无穷板的边裂纹、复杂几何条件下的边裂纹的扩展状态进行了分析，表明新程序有不依赖网格密度和单元类型，具有无需指定裂纹扩展的路径并分析裂纹扩展路径快速准确的特点。 ④运用Abaqus软件建立了SWFC试验梁的有限元实体模型，分别按扩展有限元和损伤因子模型两种方法分析了裂纹扩展路径，与试验结果对比分析表明扩展有限元分析模型能更好的描述裂纹扩展路径。
[Abstract]:In the finite element analysis of reinforced concrete structures, the crack treatment of members is always a hot and difficult point in this field. In this paper, based on the analysis and summary of the extended finite element theory, Relying on Professor Zhou Zhixiang's scientific and technological project "Application of SWFC Composite structure in continuous rigid frame Bridges in Tibet", the following main research work has been carried out:. 1 on the basis of summing up the existing research results of extended finite element method, the crack tip stress expression with the unknown stress intensity factor is derived, and the enrichment function of the crack tip is interpolated into the canonical form function by using the unit decomposition method. The matrix representation of a new form function is obtained. 2 based on the principle of ABAQUS extended finite element, based on Matlab, according to the limit strain rate expansion criterion and the improved limit strain rate expansion criterion, the enrichment function of crack tip is realized. The extended finite element analysis program is written. The expanded finite element program not only considers the enrichment function of cracked elements, but also describes more accurately the progressive field of crack tip by using the enrichment function of crack tip. The stress change at the crack tip is accurately tracked. The program uses the sub-triangle method to reencrypt the density of the crack tip mesh and uses the level set function to express the crack propagation path. (3) the Matlab-XFEM program is used to analyze the edge cracks in infinite plates, the static state of multi-angle cracks in plates and the edge cracks in infinite plates, and the propagation states of edge cracks in infinite plates under complex geometric conditions. It is shown that the new program does not depend on mesh density and element type. There is no need to specify the path of crack growth and the analysis of the path of crack growth is rapid and accurate. (4) the finite element model of SWFC test beam is established by using Abaqus software, and the crack propagation path is analyzed according to the two methods of propagation finite element method and damage factor model, respectively. Compared with the experimental results, it is shown that the propagation finite element analysis model can better describe the crack growth path.
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U445.71

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