含可更换耗能梁段的钢框筒结构滞回性能研究

RESEARCH ON HYSTERETIC BEHAVIOR OF STEEL FRAMED-TUBE STRUCTURES WITH REPLACEABLE SHEAR LINKS

传统钢框筒结构(SFTSs)的裙梁跨深比较小,梁端往往先于柱端形成塑性铰,使得结构的延性和耗能能力较差。针对这一问题,提出在裙梁跨中设置易于更换的剪切型耗能梁段,即含可更换耗能梁段的钢框筒结构(SFTS-RSLs)。设计了30层的SFTS和SFTS-RSL算例结构,从中选取子结构进行精细化有限元分析,研究结构的滞回性能,并对整体算例结构进行非线性静力和动力分析,研究结构的整体抗震性能。分析结果表明:SFTS和SFTS-RSL具有相同的初始弹性刚度;相较于SFTS,SFTS-RSL具有较低的屈服荷载和极限荷载,较高的延性和耗能能力;设置耗能梁段可以减小结构的层间侧移,且不会加剧结构的剪力滞后效应;SFTS-RSL的损伤主要集中于耗能梁段,其余构件始终保持弹性状态。研究结果表明SFTS-RSLs是一种性能优良的双重抗侧力结构体系,可以通过更换耗能梁段实现震后结构功能的可快速恢复。

In steel frame-tube structures(SFTSs), the plastic hinges usually form at column-ends before beam-ends due to the low span-to-height ratio of deep beams, which can lead to lower ductility and energy dissipation capacity of the SFTSs. To address this problem, a replaceable shear link, acting as a ductile fuse at the midspan of deep beams, was proposed. In order to evaluate this proposal, buildings were designed to compare the seismic performance of SFTS-RSLs and SFTSs. Several sub-structures were selected from the design buildings, and finite element models(FEMs) were established to study their hysteretic behaviors. The nonlinear static pushover analysis and dynamic analysis were undertaken in comparing the seismic performance of the FEMs for each building. The results indicated that the SFTS-RSL and SFTS had similar initial elastic stiffness. Compared with the SFTS, the SFTS-RSL had lower yield strength and maximum strength, but higher ductility and energy dissipation capacity. The SFTS-RSL had lower interstory drift compared with the SFTS. Placing a shear link at the beam mid-span did not increase shear lag effects for the structure. The SFTS-RSL concentrated plasticity on the shear links. Other structural components remained elastic during the seismic loading. It could be expected that the SFTS-RSL would be a reliable dual resistant system, which could offer the benefit of being able to repair the structure rapidly by replacing the damaged shear links after earthquakes.