Fluctuating Wind Cross-spectral Analysis, Research And Complex Spatial Structure Of The Cqc Wind Vibration

In line with the social and technological development, engineering structures are becoming larger and more complicated. For the large-span, high-rise and towering structures, the wind loads are usually the major factors which control the security of the structures. Therefore, wind induced dynamic response of the complicated structures is paid more and more attention to. To the engineering application, resisting wind analysis of structures carries on almost within frequency domain. It is well-known that the application of the Square-Root-of-Sum-of-Squares (SRSS) method in wind-induced effects analysis for combining modal maxima can cause significant errors.based on the theory of random vibration,finite element method and numerical analysis, As a method of model combination , in this paper, CQC(Complete Quadratic Combination)method is used to calculate the wind-induced effects, the real and imaginary part of power Spectra of wind Loads are considered at the same time.The main works include the following aspects:The paper summarizes methods to describe fluctuating wind pressure, and adopts random vibration theory in the calculation of wind-induced responses within frequency domain.The amended periodogram method presented by Welch is used to estimate the auto-spectrum and the cross-spectrum with the real and imaginary part of the disturbing wind pressures. Overlap mode and window function are considered. Related research is performed via program on Fortran platform. And two examples are given to test that the program is effective and correct.The programs of CQC and SRSS method of wind-induced response are prepared, the imaginary part of the cross-spectrum of the fluctuating wind loads is considered. Infinite integral is replaced by simple but effective composite trapezoidal formula.Based on the wind tunnel data ,the wind-induced effect on a classic high-rise building has been analyzed by CQC and SRSS method. The sparse matrix is used to reduce the calculation time. Finally the results from CQC method and SRSS method are discussed and compared.