摘要
为了研究高烈度区地震动多点激励对框架结构抗震性能的影响,基于多自由度空间结构体系地震响应分析的基本理论,采用大刚度法(LSM)在结构动力分析中的实现方式,并以实际工程为背景建立框架结构有限元模型,对该框架结构进行地震动力弹塑性计算,分析该类结构在青海高烈度区单点一致和多点非一致地震激励作用下的响应特点及抗震性能。结果表明:与单点一致激励相比,多点非一致激励会明显增大结构首层位移角,平均层间位移角由1/214增大为1/141;减小基底剪力和弯矩,其平均值分别降低了4%和3%;结构X方向的顶层位移减小,Y方向增大,Z方向则基本不变;并且多点非一致激励对结构层间位移的影响会随着结构基础支座间地震响应时间差的增大而减弱,X方向上的位移减弱效果明显,Z方向上仅出现响应滞后现象。故多点非一致激励能够更接近地震发生时的真实情况,对建筑结构采取多点非一致激励下的动力弹塑性分析很有必要。
In order to explore the effects of multi-point excitation of seismic ground motion in high intensity area on the seismic performance of frame structures,based on the basic theory of seismic response analysis of multi degree of freedom space structure system and the implementation of large stiffness method(LSM)in structural dynamic analysis,a finite element model of frame structures is established under the background of practical projects.The seismic dynamic elastic-plastic calculation is carried out for the frame structure.The response characteristics and seismic performance of the structure under single point consistent and multi-point inconsistent seismic excitation in Qinghai high intensity area are analyzed.The results show that compared with single point uniform excitation,multi-point non-uniform excitation will significantly increase the first floor displacement angle of the structure,and the average interlayer displacement angle will increase from 1/214 to 1/141.The average values of base shear and bending moment are reduced by 4% and 3% respectively.The top floor displacement of the structure decreases in the X direction,increases in the Y direction and remains unchanged in the Z direction.Moreover,the influence of multi-point non-uniform excitation on the interlayer displacement of the structure will be weaken with the increase of time difference of seismic response between the structural foundation supports.The effect of displacement reduction in the X direction is obvious,and only the response lag phenomenon appears in the Z direction.The multi-point non-uniform excitation can be closer to the real situation when the earthquake occurs.Therefore,it is necessary to adopt the dynamic elastoplastic analysis of buildings under the multi-point non-uniform excitation.
作者
周乐祥
杨青顺
卫骏
陈飞
ZHOU Lexiang;YANG Qingshun;WEI Jun;CHEN Fei(School of Civil Engineering,Qinghai University,Xining 810016,China)
出处
《青海大学学报》
2023年第1期57-64,共8页
Journal of Qinghai University
基金
青海省科学技术厅项目(2019-ZJ-975Q)。
关键词
多点非一致激励
弹塑性分析
有限元模拟
抗震性能分析
multi-point non-uniform excitation
elasto-plastic analysis
finite element simulation
seismic performance analysis
