基于点面接触的三维结构地震接触模拟  

Seismic contact modeling of three-dimensional structures based on the node-to-segment contact technique

作　　者：钟红 郭胜山 涂劲[1] 李德玉[1] 王海波[1] ZHONG Hong;GUO Shengshan;TU Jin;LI Deyu;WANG Haibo(China Institute of Water Resources and Hydropower Research,Beijing 100048,China)

机构地区：[1]中国水利水电科学研究院工程抗震研究中心,北京100048

出　　处：《中国水利水电科学研究院学报（中英文）》2022年第4期287-294,共8页Journal of China Institute of Water Resources and Hydropower Research

基　　金：国家自然科学基金项目(51979292)。

摘　　要：工程结构包括拱坝、岩质边坡等在强地震作用下可能沿结构面、节理面等产生滑移,对接触面的模拟关乎结构抗震安全评价的可靠性。本文针对结构在地震作用下接触面产生较大滑移的情况,提出采用点面接触模型和动接触力模型进行模拟。推导了适于点面接触的动接触力模型公式;采用主从接触算法,通过全局搜索缩小搜索范围,在局部搜索层次基于内外算法确定接触点对,避免经典点面算法中存在的盲区问题,提高搜索判断的精度和效率。采用经典楔形体稳定问题对本文模型进行了验证,通过施加地震激励研究其动力稳定性,并将点面接触和点点接触的计算结果进行比较,发现前者获得的结构响应大于后者,且其差异随着地震加速度幅值的增大而增大。进一步将该模型应用于拱坝的地震响应分析,结果表明对于相对较小的地震,两种接触模型计算结果基本一致;但对于超强地震,横缝发生较大相对位移,点点接触模型的计算结果偏小,对应力值的低估更为明显。总的来说,对于结构在强地震作用下产生较大滑移的情况,采用点面接触模型可更好地反映实际情况。For engineering structures such as arch dams and rock slopes,sliding may take place along the joint surfaces and cracks due to strong earthquake shocks,and thus the contact modeling of the surfaces is important to the seismic safety evaluation of the structures.For the case of large sliding along the contact faces,a procedure based on the node-to-segment(NTS)contact technique and dynamic contact force model is presented.The dy⁃namic contact force model is reformulated to couple with the NTS technique.Based on the master-slave tech⁃nique,global searching is used to reduce the searching effort,and the inside-outside technique is employed for local searching to determine the contact pairs,by which the dead zone problem typical in classic NTS algorithm can be avoided,therefore improving the accuracy and efficiency.The presented procedure is verified by the stabil⁃ity analysis of a wedge.By introducing seismic excitation,the dynamic stability of the wedge is investigated,and the results are compared with those of the node-to-node(NTN)technique.It’s found that the response of the wedge by using the NTS technique is greater than that of the NTN technique,and this difference increases as the amplitude of acceleration time history increases.This model is also applied to the seismic analysis of an arch dam.It’s found that for a relatively small earthquake,both of the contact models lead to consistent results.For a very strong earthquake,however,when significant displacement of the contraction joints occur,the response obtained by the NTN model is smaller,which is especially true for the stress response.So for the cases with significant slid⁃ing of contact faces,the NTS contact technique is preferable as it can reflect the real situation better.

关 键 词：接触模拟 地震 点面接触 动接触力模型 楔形体稳定 拱坝 横缝 

分 类 号：TV312[水利工程—水工结构工程]