Single-story steel structure with LVEM-isolated floor: Elastic seismic performance and design response spectrum
Single-story steel structure with LVEM-isolated floor: Elastic seismic performance and design response spectrum
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DOI：
10.1016/j.engstruct.2019.109314
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发表时间：
2019-10
影响因子：
5.5
通讯作者：
Yang Xiang;Y. Koetaka;N. Okuda
中科院分区：
文献类型：
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作者：
Yang Xiang;Y. Koetaka;N. Okuda
通过使用层压粘弹性材料（LVEM）隔离地板，可以降低结构的抗震需求。这种lem隔震楼板系统具有嵌入式大质量隔震比、减轻楼板加速度、易拆除等优点。本文主要研究单层钢结构lvm隔震楼板系统的弹性抗震性能，lvm隔震楼板系统采用丙烯酸粘弹材料。建立了结构体系的数值模拟方法和动力分析程序。在此过程中，用Kelvin-Voigt模型对LVEM隔离器进行了模拟。通过振动台试验验证了数值模拟方法的有效性。基于广泛的响应历史分析结果，量化了几个关键参数对弹性结构抗震需求的影响。考虑的参数包括结构自然周期(T)、质量隔离比和LVEM隔振器的刚度。得到了对应于环境温度θ= 20 ℃时子结构和LVEM隔振器的位移响应谱，即λ s - t谱和λ vem - t谱。在结构设计中，λSis用于校核下部结构的抗震能力，λ vemis用于确定LVEM隔振器的适当变形空间。随着LVEM隔震器柔韧性的增强和质量隔震比的增大，下部结构的抗震需求普遍降低。分析了环境温度变化对弹性设计谱的影响。一般情况下，随着质量隔离比的增大和LVEM隔振器刚度的减小，这种效应更为明显。为量化环境温度变化对λ s -t光谱和λ vem -t光谱的影响提供了分析数据。根据这些数据，可以有效地进行结构设计和评估。
The seismic demand of a structure could be reduced by isolating the floors using laminated visco-elastic materials (LVEM). Such a LVEM-isolated floor system exhibits many advantages, such as the embedded large mass-isolation ratio, the mitigation of floor acceleration, the easy-to-demolish characteristic, etc. This paper focuses on the elastic seismic performance of single-story steel structures equipped with the LVEM-isolated floor system, wherein the LVEM-isolators are made of acrylic visco-elastic materials. The numerical simulating approach and the dynamic analysis procedure are developed for the structural system. In the procedure, the LVEM isolators are simulated by the Kelvin-Voigt model. The numerical simulating approach is validated by shaking table tests. Based on the results of an extensive response history analysis, the effects of several key parameters on the elastic structural seismic demand are quantified. The considered parameters include the structural natural period (T), the mass-isolation ratio, and the stiffness of the LVEM isolators. The displacement response spectra for both the substructure and the LVEM isolators, namely, theλS−Tspectra and theλVEM−Tspectra, are developed corresponding to the ambient temperatureθ= 20 °C. In the structural design,λSis used for checking the seismic capacity of the substructure, whileλVEMis used for determining an appropriate deforming space for the LVEM isolators. The seismic demand of the substructure generally decreases as the LVEM isolators become more flexible and the mass-isolation ratio becomes larger. The effect of ambient temperature-changing on the proposed elastic design spectra is analyzed. Generally, such effect is more pronounced when the mass-isolation ratio increases and the stiffness of the LVEM isolator decreases. Analysis data is provided for quantifying the effect of ambient-temperature-changing on theλS−Tspectra and theλVEM−Tspectra. Based on the data, the structural design and evaluation could be carried out efficiently.