高层建筑风振分析中的模态组合问题
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- 英文论文题名：Modal Combinations in Prediction of Wind-Induced Building Responses
- 论文作者：汤昱薇 ; 谢霁明
- 英文论文作者：TANG Yuwei ; XIE Jiming ; Zhejiang University
- 年：2016
- 作者机构：浙江大学大学建筑工程学院;
- 论文关键词：高层建筑抗风设计 ; 结构风效应 ; 模态相关性 ; 模态组合法 ; CQC法 ; 基于互谱密度函数的CS法
- 英文论文关键词：wind effects on tall buildings ; wind-resistant design ; modal correlations ; modal combinations ; CQC method ; CS method
- 会议召开时间：2016-07-28
- 会议录名称：第二十七届全国振动与噪声应用学术会议论文集
- 语种：中文
- 分类号：TU973.2
- 学会代码：ZDZD
- 会议名称：第二十七届全国振动与噪声应用学术会议
- 会议地点：中国黑龙江哈尔滨
- 主办单位：中国振动工程学会振动与噪声控制专业委员会
- 学会名称：中国振动工程学会振动与噪声控制专业委员会
- 页数：5
- 文件大小：1277k
- 原文格式：D
- 会议级别：全国
摘要
大多数超高层建筑具有两个侧移振动固有频率非常接近的特点,使得风振响应分析中不能忽略其模态相关性。但目前普遍采用的SRSS与CQC模态组合方法存在理论上的不足,在实际工程应用中不能正确把握风致结构响应特点,对结构的抗风优化设计带来一定的困惑甚至误导。SRSS方法完全忽略了模态相关性。CQC方法虽然在一定程度上考虑了模态相关性,但未能反映模态相关性中的相位关系,导致过于保守的计算结果。根据随机振动的基本理论,本文建立了基于风荷载互谱密度函数的模态组合新方法(称为"CS模态组合法")。这一方法能够完整考虑相邻模态之间的幅值相关性与相位相关性,原理清晰,计算简单,具有实际可操作性。与时域模拟结果的比较验证了这一新方法的可靠性与精确性。
Most super-tall buildings have the natural frequencies of the first two sway modes being very close to each other.For this type of structures,it has been well recognized that the modal correlation effects cannot be ignored in their wind response analysis.However,the current available methods of modal combinations,SRSS and CQC methods,are found to be inadequate to address the modal correlations for wind effects,and the results with these methods can lead to incorrect prediction on wind response or cause confusion in structural optimization design.While SRSS method totally neglects the modal correlations,CQC method takes into account of modal correlations for magnitude but overlooks their phase correlations.Therefore CQC method often results in overly conservative estimates on wind responses.Based on fundamental principles of random vibrations,a new method of modal combinations is proposed in this paper.The new method makes use of information from cross-spectrum of aerodynamic forces to precisely estimate the modal correlations in both magnitude and phase angles,and is therefore referred as"CS method".Owing to its clear presentation in principle and easy adoption in calculation,this method is ready for engineering applications.Time domain simulation validates the precision and reliability of this new method.
Most super-tall buildings have the natural frequencies of the first two sway modes being very close to each other.For this type of structures,it has been well recognized that the modal correlation effects cannot be ignored in their wind response analysis.However,the current available methods of modal combinations,SRSS and CQC methods,are found to be inadequate to address the modal correlations for wind effects,and the results with these methods can lead to incorrect prediction on wind response or cause confusion in structural optimization design.While SRSS method totally neglects the modal correlations,CQC method takes into account of modal correlations for magnitude but overlooks their phase correlations.Therefore CQC method often results in overly conservative estimates on wind responses.Based on fundamental principles of random vibrations,a new method of modal combinations is proposed in this paper.The new method makes use of information from cross-spectrum of aerodynamic forces to precisely estimate the modal correlations in both magnitude and phase angles,and is therefore referred as"CS method".Owing to its clear presentation in principle and easy adoption in calculation,this method is ready for engineering applications.Time domain simulation validates the precision and reliability of this new method.
引文
[1]Xie,J.,Kumar S,and Gamble S.,Wind loading study for tall buildings with similar dynamic properties in orthogonal directions[P].2003,Proc.,11th Int.Conf.Wind Eng.Lubbock,Texas
[2]Tschanz T,Davenport A.G.,The base balance technique for the determination of dynamic wind loads[J].J.Wind Eng.Ind.Aerody.,1983,13:429-439.
[3]Boggs,D.W.,Validation of the aerodynamic model method[J],J.Wind Eng.Ind.Aerody.,1992,41-44,1011-1022
[4]Irwin P.A.&Kochanski W.W.,Measurement of structural wind loads using the high frequency pressure integration method[P],1995,Proc.ASCE Structures Congress,Boston,1631-1634
[5]Xie J.,&To A.,Design-orientated wind engineering studies for CCTV new building[P],2005,Proc.6th Asia-Pacific Conf.on Wind Eng.,Seoul,Korea
[6]Holmes J.D.,Mode shape corrections for dynamic response to wind[J],J.Eng.Struct.,1987.9,210-212.
[7]Xie J.and Irwin P.A.,Application of the force balance technique to a building complex[J],1998,J.Wind Eng.Ind.Aerody.,77-78(98),579-590.
[8]Xie J.&Garber J.,HFFB Technique and Its Validation Studies[J].Wind&Structures,An International Journal,2014.No.4.
[9]Wilson,E.L.,Kiureghian,A.D.and Bayo,E.R.,A replacement for the SRSS method in seismic analysis[J],Earthquake Engineering and Structural Dynamics.1981.Vol.9
[2]Tschanz T,Davenport A.G.,The base balance technique for the determination of dynamic wind loads[J].J.Wind Eng.Ind.Aerody.,1983,13:429-439.
[3]Boggs,D.W.,Validation of the aerodynamic model method[J],J.Wind Eng.Ind.Aerody.,1992,41-44,1011-1022
[4]Irwin P.A.&Kochanski W.W.,Measurement of structural wind loads using the high frequency pressure integration method[P],1995,Proc.ASCE Structures Congress,Boston,1631-1634
[5]Xie J.,&To A.,Design-orientated wind engineering studies for CCTV new building[P],2005,Proc.6th Asia-Pacific Conf.on Wind Eng.,Seoul,Korea
[6]Holmes J.D.,Mode shape corrections for dynamic response to wind[J],J.Eng.Struct.,1987.9,210-212.
[7]Xie J.and Irwin P.A.,Application of the force balance technique to a building complex[J],1998,J.Wind Eng.Ind.Aerody.,77-78(98),579-590.
[8]Xie J.&Garber J.,HFFB Technique and Its Validation Studies[J].Wind&Structures,An International Journal,2014.No.4.
[9]Wilson,E.L.,Kiureghian,A.D.and Bayo,E.R.,A replacement for the SRSS method in seismic analysis[J],Earthquake Engineering and Structural Dynamics.1981.Vol.9