基于数值流形法的重力坝多裂纹扩展研究

发布时间：2019-05-12 02:43

【摘要】：传统数值流形法(NMM)在处理非连续变形问题时,仅限于几何构型不发生破坏的情况。针对这一不足,通过在裂纹尖端附近的物理片上增加用于模拟应力奇异性的增强位移函数,进一步发展了可用于几何构型破坏的扩展的高阶NMM。然后,将其应用到重力坝由连续到非连续的破坏过程分析中。首先,针对一含单裂纹的重力坝模型进行了敏感性分析,结果表明,在不同的扩展长度或网格密度下,其扩展路径基本相同且与文献结果保持一致。进而在此模型基础上又开展了多裂纹扩展分析,结果仅一条主导裂纹发生扩展,与文献结果基本一致。最后,针对印度的Koyna重力坝,通过设置不同的漫顶高度研究了其裂纹扩展路径的变化。结果表明,随着漫顶高度的增大,裂纹扩展路径逐渐趋向于水平方向扩展,而且坝体抵抗破坏的能力逐渐减弱。总体表明,NMM在求解实际工程问题时具有很好的数值稳定性和鲁棒性。
[Abstract]:When dealing with the problem of discontinuity deformation, the traditional numerical flow method (NMM) is limited to the case where the geometry is not destroyed. In order to solve this problem, by adding the enhanced displacement function to the physical film near the crack tip to simulate the stress singularity, the higher order NMM. which can be used for the propagation of geometric configuration failure is further developed. Then, it is applied to the failure process analysis of gravity dam from continuous to discontinuous. Firstly, the sensitivity analysis of a gravity dam model with single crack is carried out. The results show that the propagation path is basically the same under different propagation length or grid density and is consistent with the results in the literature. On the basis of this model, the multi-crack propagation analysis is carried out, and only one dominant crack propagates, which is basically consistent with the results in the literature. Finally, the crack propagation path of Koyna gravity dam in India is studied by setting different overtopping heights. The results show that with the increase of the height of the overtopping, the crack propagation path tends to propagate horizontally, and the ability of the dam body to resist failure is gradually weakened. It is shown that NMM has good numerical stability and robustness in solving practical engineering problems.
【作者单位】：长江科学院水利部岩土力学与工程重点实验室;中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室;
【基金】：国家自然科学基金(No.11502033,No.51579016,No.51309025,No.41672320) 国家重点基础研究发展计划(973)项目(No.2011CB710603)~~
【分类号】：O346.1

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