中心支撑钢框架抗震性态评估——屈服点谱法

Seismic Performance Evaluation of Concentrically Braced Steel Frames——Yield Point Spectra Method

屈服点谱(Yield Point Spectra,YPS)是一种新的位移-加速度反应谱形式。YPS方法可以用于对现有结构进行抗震评估,确定结构在给定地震作用下的峰值位移和延性,而且该方法形式简洁,概念清楚,与动力时程分析结果相比较,具有足够的精度。本文根据单条地震波构造了YPS图,对一个6层3跨的中心支撑钢框架结构进行峰值位移和层间位移角(Interstory Drift Indices,IDI)评估,结果表明按照我国现行规范设计的中心支撑钢框架结构在设防地震作用下充分发挥了塑性,在罕遇地震下作用下接近我国规范的弹塑性位移角限值,满足中震可修、大震不倒的设防要求。

Yield Point Spectra （YPS） is a new response spectrum with displacement-acceleration. The YPS method is used to value the seismic performance of the present building so as to estimate the peak displacement and ductility under the given earthquake. The method is simple, clear, and more accurate than the dynamic timehistory analysis. This paper presented the YPS according to the single earthquake wave and evaluated the peak displacement and interstory drift indices （IDI） of a concentrically braced steel frame （CBSF） with six stories and three bays. The result indicates that the CBSF designed according to the present China code will give a full play of the inelastic under the moderate earthquake; and the IDI is close to the elasto-plastic inter-drift limit required in the present China code under the rare earthquake, which can meet the requirement of ＂being repairable under the moderate earthquake, non-collapse under the strong earthquake＂.