背景和共振响应的时域划分及模态耦合简化分析  

Background response and resonant response divided in time domain and simplified analysis for modal coupling effects

作　　者：李玉学[1,2] 杨庆山[3] 田玉基[3] 向敏[1,2] 

机构地区：[1]石家庄铁道大学土木工程学院,河北石家庄050043 [2]石家庄铁道大学道路与铁道工程安全保障省部共建教育部重点实验室,河北石家庄050043 [3]北京交通大学结构风工程与城市风环境北京市重点实验室,北京100044

出　　处：《振动工程学报》2015年第2期269-276,共8页Journal of Vibration Engineering

基　　金：国家自然科学基金资助项目(51278314;51378061);河北省自然科学基金资助项目(E2012210002);教育部博士点基金资助项目(20120009110037);河北省高等学校科学技术研究优秀青年基金资助项目(YQ2013028);石家庄铁道大学优秀青年基金资助项目(Z9901503)

摘　　要：大跨屋盖结构风振响应具有多模态参振及模态耦合效应显著的特点。结合模态加速法基本思想,基于时程响应划分了大跨屋盖结构风致背景响应和共振响应,并推导了各自的计算公式,其中背景响应能够考虑所有模态及其耦合项的贡献。对于共振响应,引入模态能量的概念,由结构动力特征参数及风荷载参数定义模态耦合系数,据此识别强耦合模态。在此基础上,结构总共振响应可以由各参振模态的SRSS(平方和开平方,Square root of sum of squares)组合结果叠加强耦合模态的贡献得到,从而避免复杂的CQC(完全二次型,Complete quadratic combination)组合计算,实现有效考虑模态耦合效应的目的。最后,通过国家体育场屋盖主结构风致背景响应和共振响应计算对所提方法的有效性进行了验证。The wind-induced response of large-span roofs features with multi-mode participating and modal coupling effects sig-nificantly.Combined with idea of modal acceleration method and based on time-history response,wind-induced background re-sponse and resonant response of large-span roofs are divided,besides,the corresponding expression formulas are deduced re-spectively.The contributions of all modes and their coupling effects are take into account for background response expression formula.For resonant response,introduced the concept of modal strain energy,the modal coupling coefficient is defined by pa-rameters of both structural dynamic characteristics and fluctuating wind loads,which can be used to select coupling dominant modes.On the base of this,total resonant response can be obtained by combining the SRSS （Square root of sum of squares） results of each participant modes with the contributions of dominant coupling modes,so the complicated CQC（Complete quad-ratic combination）calculation is avoided,and the modal coupling effects are considered effectively.Finally,the effectiveness of the proposed method is verified by the analysis of wind-induced background response and resonant response for the main roof structure of the National Stadium.

关 键 词：大跨屋盖 时程响应 背景响应 共振响应 模态耦合 

分 类 号：TU311.3[建筑科学—结构工程] TU312.1