Evaluation of the Modal Coupling Effect in Midstory Isolation Systems Based on Random Vibration Analysis
Evaluation of the Modal Coupling Effect in Midstory Isolation Systems Based on Random Vibration Analysis
复制标题
DOI：
10.1155/2021/9382235
复制
发表时间：
2021-09
影响因子：
1.6
通讯作者：
Xiao Song;Songtao Xue
中科院分区：
文献类型：
--
作者：
Xiao Song;Songtao Xue
目前，中层隔震技术在历史建筑改造和多功能建筑中具有很大的应用潜力。隔震层位置的变化引起的耦合效应可能会放大结构的地震反应，这是进行深入分析所必需的。本文的目的是评估耦合效应的大小，并划定考虑耦合效应的区域。基于复振型叠加法，推导了简化模型随机响应的显式计算公式。采用上部隔震体系剪力系数的均方根(RMS)比作为性能指标来评价MSI体系的耦合放大效果。参数分析表明，耦合区域与上下结构与隔震层的质量比和频率比密切相关。通常，根据性能指标的阈值，根据频率比的参数，要考虑的耦合效应区域可以分为两部分。随着上隔振系统与整个系统质量比的增大，其中一个耦合区域逐渐缩小并最终消失，说明在一定条件下，该区域的耦合放大效应可以忽略。最后，对三个具有代表性的微星结构数值算例进行了时程分析，验证了频域分析结果的可靠性。研究成果可为微星结构的初步设计提供技术指导。
At present, the midstory isolation (MSI) technology has great potential for application in historical buildings’ retrofitting and multifunction buildings. The coupling effect due to the variability of the location of the isolation layer may amplify the structural seismic response and is required for in-depth analysis. This paper aims to evaluate the magnitude of the coupling effect and delimitate the region of the coupling effect to be considered. Based on the complex mode superposition method, the explicit formulas for calculating the random response of the simplified model are deduced. The root-mean-square (RMS) ratio of the shear force coefficient of the upper isolation system is adopted as the performance indicator to evaluate the coupling amplification effect of the MSI system. Parameter analysis indicates that the coupling region is closely related to the mass ratio and frequency ratio of the upper and lower structures to the isolation layer. In general, the region of the coupling effect to be considered can be divided into two parts according to parameters of frequency ratios, depending on the thresholds of the performance indicator. As the mass ratio of the upper isolation system to the entire system increases, one of the coupling regions shrinks and eventually disappears, indicating that the coupling amplification effect in this region can be neglected under certain conditions. Finally, the time-domain analysis of three representative numerical cases of MSI buildings was performed to verify the reliability of the results obtained from the frequency-domain analysis. The research results can provide technical guidance for the preliminary design of the MSI buildings.