一种考虑高阶振型影响的模态条件均值目标谱方法研究  

A MODAL CONDITIONAL MEAN TARGET SPECTRUM METHOD TO CONSIDER HIGHER MODE EFFECT

作　　者：高嘉伟 杜轲[1,2] GAO Jia-wei;DU Ke(Institute of Engineering Mechanics,China Earthquake Administration,Harbin 150080,China;Key Laboratory of Earthquake Engineering and Engineering Vibration of China Earthquake Administration,Harbin 150080,China)

机构地区：[1]中国地震局工程力学研究所,哈尔滨150080 [2]中国地震局地震工程与工程振动重点实验室,哈尔滨150080

出　　处：《工程力学》2022年第3期23-32,共10页Engineering Mechanics

基　　金：国家自然科学基金项目(51878631);黑龙江省自然科学基金项目(LH2019E098)。

摘　　要：采用传统条件均值谱作为目标谱匹配选波未能有效考虑结构的高阶振型影响,针对这一缺陷,在条件均值谱方法的理论基础上,提出了一种考虑高阶振型影响的模态条件均值谱方法。该方法以振型参与质量系数作为权重,将各振型下的条件均值谱组合起来,得到一条新的目标谱,称为模态条件均值谱。设计了一座30层的钢框架-中心支撑结构,分别生成其主周期的条件均值谱、模态条件均值谱以及一致危险谱作为目标谱,各选取11条地震动进行结构动力时程分析。结果表明,考虑了结构高阶振型影响的模态条件均值谱方法得出的结构响应,明显大于不考虑高阶振型影响的传统条件均值谱的结果。建议此方法推广用于高层工程结构作为目标谱。The traditional method uses conditional mean spectrum as the target spectrum to select ground motion,which fails to effectively take into account the influence of high mode vibration of the structure.To overcome this shortcoming,a modal conditional mean spectrum method considering the influence of higher mode effect is proposed.With the weight coefficients of mode participation mass ratios,the proposed method combines the conditional mean spectrum of each mode to obtain a new target spectrum,and is called the modal conditional mean spectrum.A 30-story steel frame-center support structure was designed,and the mean conditional spectrum of interested period,modal mean conditional spectrum and uniform hazard spectrum were generated,and then 11 ground motions were selected for structural dynamic time history analysis with the 3 target spectra respectively.The results show that the structural response obtained by the modal conditional mean spectrum method considers the influence of higher mode effect of the structure,and generates obviously greater result than the traditional conditional mean spectrum.It is suggested that the proposed method be extended to high-rise structures as target spectrum.

关 键 词：条件均值谱 模态条件均值谱 动力时程分析 高阶振型 钢框架-中心支撑结构 

分 类 号：TU355[建筑科学—结构工程] P315.9[天文地球—地震学]