摘要
大跨度复杂悬挑屋盖结构存在模态频率密集和模态耦合明显等特征,传统频域完全二次型组合(CQC)法和时域方法均不同程度存在计算效率低下和内存需求巨大的问题而不适用于此类结构的风致响应计算。谐波激励法(HEM)和基于Ritz-POD的CQC(RPCQC)方法的提出实现了精度和CQC法一致的快速计算,这使得复杂大跨度屋盖结构风致响应的计算成为可能。为考虑高阶模态对屋盖风致响应的影响,提出了基于Ritz-POD的HEM(RPHEM),并用于深圳国际会展中心屋盖的风振分析,以SAP2000时域积分结果为标准,对比了不同参振模态阶数的自由振动模态和基于Ritz-POD模态对HEM计算结果的影响。结果表明,采用HEM需要500阶自由参振模态才能得到满意的结果,且其计算时间仅为SAP 2000的1/30,而采用120阶Ritz-POD模态即可达到同样精度,且所需时间仅为采用HEM的1/6,大大减少了HEM的计算量。如果采用已有的RPCQC方法,其存储120阶模态力谱矩阵所需的内存量为1.93 GB,且计算耗时同CQC方法一样巨大,这表明所提方法的有效性。
The large-span complex cantilevered roof structure characterizes dense modal frequency and remarkable modal coupling. Complete Quadratic Combination(CQC) method and time domain method in traditional frequency domain both have low computing efficiency and extensive computer memory requirements to some extent, and hence not suitable for calculating the wind-induced response of such structures. The proposed Harmonic Excitation Method(HEM) and Ritz-POD based CQC(RPCQC) method achieve fast calculation with the same accuracy as CQC method, which makes it possible to calculate the wind-induced response of large-span complex roof structures. In order to consider the influence of higher modes on the wind-induced response of roofs, a Ritz-POD based HEM method(RPHEM) was proposed and applied in the wind-induced vibration analysis for the roof of Shenzhen International Convention and Exhibition Center. Using SAP2000 time-domain integration results as a standard, the effects of free vibration modes and Ritz-POD modes with various modal orders on the calculation results of HEM were evaluated. The results show that 500 order free vibration modes are needed for HEM to get satisfying results, and the calculation time is only 1/30 of that from SAP2000. In comparison, 120 order Ritz-POD modes can achieve the same accuracy and the required calculation time is only 1/6 of the former, which greatly reduces the calculation time for HEM method. If the existing RPCQC method is used, the computer memory required to store the 120 order modal force spectrum matrix is 1.93 GB, and the calculation time is as enormous as CQC method, which indicates the effectiveness of the proposed method.
作者
刘彪
谢壮宁
黄用军
傅继阳
LIU Biao;XIE Zhuangning;HUANG Yongjun;FU Jiyang(State Key Laboratory of Subtropical Building Science,South China University of Technology,Guangzhou 510641,China;Guangzhou Times Holdings Group Co.,Ltd.,Guangzhou 510403,China;Shenzhen Aube Engineering Architectural Design Co.,Ltd.,Shenzhen 518053,China;Guangzhou University-Tamkang University Joint Research Center for Engineering Structure Disaster Prevention and Control,Guangzhou 510006,China)
出处
《建筑结构学报》
EI
CAS
CSCD
北大核心
2021年第4期7-14,共8页
Journal of Building Structures
基金
国家自然科学基金项目(51778243)。
关键词
大跨度悬挑屋盖
谐波激励法
时域方法
Ritz-POD法
风致响应
large-span cantilevered roof
harmonic excitation method
time domain method
Ritz-POD method
wind-induced response
