巨型框-筒结构的地震反应分析

Study on Seismic Response of Megaframe-Tube Structures

关键词:  巨型框-筒  地震反应  有限元法  时程分析

Key words:  megaframe-tube  seismic response  finite element method  time-history analyses

摘要:

采用空间有限元计算模型和时程分析方法,分析巨型框-筒结构的地震反应,比较巨型框-筒结构与普通框-筒结构的抗震性能.结果表明:两者的受力性能相似,巨型框-筒结构的前2阶自振周期比普通框-筒结构稍大,而其后13阶自振周期均比普通框-筒结构小;两者的振型图相似,第3、6阶振型以扭转为主;迁安地震波、EL Centro地震波和天津宁河地震波作用下,2种结构在控制结构体系的顶点位移、顶层速度、最大楼层加速度相差均不超过7%,而底层剪力、弯矩相差略大,且巨型框-筒的底层最大弯矩均小于普通框-筒;罕遇地震作用下,结构的顶层位移、速度、加速度反应谱相似.说明巨型框-筒结构具有良好的抗震性能,可以用于高层建筑的抗震设计.

Abstract:

The finite element method of structural dynamics is applied to analyse the seismic response of megaframe-tube structures,and a comparison is made between the megaframe-tube and traditional frame-tube structures. The results of the examples in this paper show that the characteristics of seismic response for these two kinds are similar,the first two periods of megaframe-tube structure are little more than frame-tube structure,and the next 13 periods are opposite,these two kinds of structures have similar mode shapes,the 3rd and 6th mode shapes are torsion shape.Under Qian'an,EL Centro and Tianjin Ninghe earthquake excitations,the differences of top floor displacement,velocity and acceleration of these two kinds of structures are less than 7%,but the differences of the bottom floor shear force and moment are a little bigger,and the maximum values of the bottom floor moment of the megaframe-tube structure are all less than that of frame-tube structure.Under rare seism, the top floor displacement,velocity and acceleration time histories of these two kinds of structures are similar.All these show that megaframe-tube system has a good seismic performance, and can be applied to the seismic design of tall buildings.