带低屈服点钢耗能梁段高强钢框筒结构的结构影响系数和位移放大系数研究

A Research on the Structural Influence Coefficient and Displacement Amplification Coefficient of High-Strength Steel Fabricated Framed-Tube with Low-Yield-Point Steel Shear Links

在传统钢框筒结构的部分裙梁跨中处设置LYP225低屈服点钢耗能梁段,其余构件采用Q460高强度钢材,提出带低屈服点钢耗能梁段高强钢框筒结构(HSS-FTS-LSL)。在地震作用下耗能梁段发生剪切屈服耗散地震能量,梁、柱等构件由于采用高强钢从而保持弹性或部分进入塑性阶段。为了研究HSS-FTS-LSL的结构影响系数和位移放大系数,以楼层数、耗能梁段长度及布置方式为变量,按照我国规范设计了3组共8个HSS-FTS-LSL算例,并且考虑高阶振型的影响,采用分布侧向力调整法对各算例进行了Pushover分析,基于改进的能力谱法计算了8个算例的结构影响系数和位移放大系数,分析了结构层数、耗能梁段长度及布置方式对结构性能系数的影响并给出了建议取值。最后,根据提出的HSS-FTS-LSL抗震设计反应谱对其中一个结构算例进行重设计,并对重设计前后两个算例结构进行弹塑性分析,对比了二者的抗震性能以及用钢量,验证了本文提出的HSS-FTS-LSL结构影响系数建议值的合理性。

High-strength steel fabricated framed-tube structure with low-yield-point steel replaceable shear links(HSS-FTSLSL)was proposed,in which the shear links used LYP225 low-yield-point steel in the middle of deep beam,and the columns and deep beams were made of Q460 high-strength steel.In earthquake,the shear links dissipate seismic energy through shear yield while the main component remains elastic or partially enters plasticity.To investigate the structural influence coefficient and displacement amplification factor of HSS-FTS-LSL,three groups of 8 HSSFTS-LSL calculation examples are designed based on the Chinese standards,taking the different story,the length and the layout of links as variables.Pushover analysis was carried out for each case by stepwise lateral force adjustment method considering the effects of high-order vibration mode.Based on the improved capacity spectrum method,the structural influence coefficient R and displacement amplification factor Cd of eight cases were calculated.The influence of the above three variables on the structural performance coefficient is analyzed and the recommended values are given.Finally,according to the proposed HSS-FTS-LSL seismic design response spectrum,a structural example was redesigned.The elastic-plastic analysis of two specimens before and after the redesign was carried out,and the rationality of the proposed influence coefficient of HSS-FTS-LSL structure was verified by comparing the steel consumption and seismic performance of the two specimens.