含裂纹混凝土的三维渗透性分析

发布时间：2018-02-23 13:08

本文关键词： 裂纹混凝土三维渗透性相互作用直推解嵌入单元弹性比拟　出处：《工程力学》2017年07期 　论文类型：期刊论文

【摘要】：该文假设含裂纹的混凝土材料是由孔隙基体和裂纹组成的二相复合材料,基于相互作用直推法(IDD)给出了三维周期裂纹渗透性的表达式。基于单元嵌入技术和弹性比拟的数值模拟新方法,解决了三维细观连续有限元实体模型的建模和网格划分问题,实现了含混凝土裂纹的三维渗透模拟。假设裂纹为圆盘状,引入周期性的概念并提出三维周期裂纹结构模型,分析裂纹直径、裂纹周期、裂纹倾角和裂纹间距等因素对整体等效渗透性能的影响。将得到的数值解和IDD理论解进行对比分析,结果表明:在裂纹密度较低时,数值解和理论解吻合得很好,但随着裂纹密度的增大,二者之间的误差逐渐增大;当裂纹趋于连通时,IDD解低估了裂纹之间的近场相互作用而偏离数值解;裂纹接近连通时,整体等效渗透率与裂纹密度呈对数关系,可用渐进对数表达式准确描述。
[Abstract]:In this paper, it is assumed that the cracked concrete material is a two-phase composite composed of pore matrix and crack. Based on the interaction direct method (IDD), the expression of 3-D periodic crack permeability is given. Based on the element embedding technique and the new numerical simulation method of elastic analogy, the modeling and meshing problems of three-dimensional meso-continuous finite element model are solved. The three-dimensional permeation simulation of concrete cracks is realized. The concept of periodicity is introduced, and a three-dimensional periodic crack structure model is proposed to analyze the crack diameter and crack period. The effects of crack dip angle and crack spacing on the equivalent permeability of the whole system are compared and analyzed. The results show that the numerical solution is in good agreement with the theoretical solution when the crack density is low. However, with the increase of crack density, the error between them increases gradually; when the crack tends to be connected, the IDD solution underestimates the near-field interaction between the cracks and deviates from the numerical solution; when the crack is close to connected, the IDD solution deviates from the numerical solution. There is a logarithmic relationship between the integral equivalent permeability and the crack density, which can be accurately described by the asymptotic logarithmic expression.
【作者单位】：清华大学水沙科学与水利水电工程国家重点实验室;
【基金】：国家重点基础研究发展计划(973)项目(2013CB035902) 国家自然科学基金重点项目(51339003) 水沙科学与水利水电工程国家重点实验室自主科研课题项目(2016-KY-05)
【分类号】：TU528

【参考文献】