无限元边界在半无限域动力时域分析中的应用

Application of infinite element boundary in dynamic time history analysis of semi-infinite domain

本文采用底部节点力的形式在模型底部输入正弦波,分析了利用无限元边界对半无限空间的地震响应进行数值模拟分析的可靠性。首先利用ABAQUS软件进行数值建模,并将理论解与数值解以时程曲线和均方差的形式进行对比分析,验证了无限元边界的有效性和精确度;研究了分别在剪切波和压缩波两种工况下模型宽度对动力时程分析结果的影响,并给出了推荐建模尺寸。结果表明:通过无限元边界计算半无限域的动力响应时,采用节点力的方式输入正弦波,模型的加速度时程响应与理论解基本保持一致;通过分别在模型底部输入剪切波和压缩波,发现建模尺寸对地表加速度响应的影响十分显著;取模型宽度为建模高度的4到8倍时,计算效率高,计算精度满足工程使用的要求。

In this paper, a sine wave is input at the bottom of the model in the form of bottom nodal force, and the reliability of numerical simulation analysis of seismic response in a semi-infinite space by using the boundary of infinite element is analyzed. First, use ABAQUS software for numerical modeling, and compare the theoretical and numerical solutions in the form of time history curve and mean square error to verify the validity and accuracy of the infinite element boundary. The influence of the model width on the dynamic time history analysis results under the two working conditions of wave, and the recommended modeling size is given. The results show that: when calculating the dynamic response of the semi-infinite domain through the boundary of the infinite element, the nodal force is used to input the sine wave, and the acceleration time history response of the model is basically consistent with the theoretical solution;by inputting the shear wave and the compression wave at the bottom of the model respectively, Found that the modeling size has a significant impact on the surface acceleration response;when the model width is 4 to 8 times the modeling height,the calculation efficiency is high, and the calculation accuracy meets the requirements of engineering use.