Simulation Of Non-Stationary Non-Gaussian Wind Pressure Field On Low-Rise Buildings

This thesis investigates two types of methods for simulation of non-Gaussian non-stationary wind pressure fields on low-rise buildings, that is, the unconditional simulation method and conditional simulation method. These two methods are aimed at the simulation of stationary non-Gaussian wind pressure fields and non-stationary non-Gaussian wind pressure field, respectively. The research in this thesis can be summarized as follows.In the first part of the thesis, which concerning the unconditional simulation of stationary non-Gaussian wind pressure field, the development and application of the wind field simulation methods are introduced. The characteristics and influence of the statistical parameters of wind pressure time-histories are investigated by analysis of wind tunnel test results. Two types of transformation process methods are discussed here for the simulation.(1) For the method on the basis of transformation process of simulation by the spectral representation method, the computational efficiency is improved by using interpolation method instead of double integral method to solve the correlation coefficients of the corresponding Gaussian process.(2) For the method based on the Hermite polynomial transformation, the steps of wind field simulation are simplified by setting the transformation parameters according to the statistical moment characteristics of the target wind pressure field. In this paper, the two methods are applied to non-Gaussian stationary wind pressure field on low-rise buildings in terms of the program coded by using Matlab.In the second part of the thesis, Conditional simulation of Non-stationary gaussian wind pressure field is studied first, which deals with zero-mean fourier coefficients by Kriging method. Then, the results of the conditional simulation are obtained by FFT inversion. It reduces the matrix dimensions of the Cholesky decomposition during conditional simulation, and improves the efficiency of calculation. On the basis, the problem of spectral distortion before conditional simulation is solved by correlation distortion method. The required non-stationary non-gaussian wind pressure field is acquired by time varying of the non-stationary gaussian process resulted from Hermite transform method.It proved the proposed method effective by examples.