风振响应计算的新方法——广义坐标合成法  

New approach for predicting wind-induced response-generalized coordinates synthesis method

作　　者：陈凯[1] 符龙彪[1] 钱基宏[1] 金新阳[1] 

机构地区：[1]中国建筑科学研究院,北京100013

出　　处：《振动与冲击》2012年第3期172-178,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金(50878202);建设部研究开发课题(2008-k2-33)

摘　　要：风振响应通常根据激励的功率谱矩阵,采用完全二次型组合(CQC)或其改进算法进行计算。但对于已由风洞试验给出激励时程的结构而言,采用广义坐标合成法(GCS)可获得更高的计算效率和更快的计算速度。该方法利用单自由度广义坐标方程的频域数值解法,求解广义坐标时程,进而根据振型叠加法得出响应时程或响应方差。对于加速度响应,首先计算广义坐标的加速度时程,然后再叠加。求解响应方差时,GCS的计算量和计算规模通常不到CQC改进算法的1/10,而计算结果与CQC方法完全等价。该方法的另一突出优点是可方便的得到响应时程,这为开展响应构成和概率特性的研究创造了有利条件。通过两个典型算例阐述了该方法地具体应用,证明该方法具有高效、快速、准确的特点。The wind-induced structural responses are usually predicted by the complete quadratic combination（CQC） method or its improved forms on the basis of power spectral density matrix of excitation-source.However under the condition that the excitation time history is already given by wind tunnel tests,a preferred approach named generalized coordinates synthesis（GCS） method can be more efficient and less time-consuming.The single-degree-of-freedom generalized coordinate equation was solved in frequency domain and the response time history or covariance matrix was accordingly obtained by means of mode superposition.The actual acceleration response also can be predicted from acceleration time history of generalized coordinates.If only the response covariance matrix is required,the computational cost and resource of GCS method are generally less than 10% of the traditional or improved forms of CQC method while the results are mathematically equivalent between them.Another significant advantage of GCS method is the response time history can be derived readily from the generalized coordinates,which provides convenience for study on the components and the probability distribution of responses.Two typical examples demonstrate and verify that the GCS method is efficient,fast and accurate.

关 键 词：风振响应 完全二次型组合法 虚拟激励法 谐波激励法 广义坐标合成法 

分 类 号：TU311.3[建筑科学—结构工程] O324[理学—一般力学与力学基础]