Improved Spectral Representation Method for the Simulation of Stochastic Wind Velocity Field Based on FFT Algorithm and Polynomial Decomposition

Abstract

For the simulation of fluctuating wind velocity field with n processes, the existing spectral representation method requires a total of n(n+1)/2 executions of the fast Fourier transform (FFT) algorithm. This requirement is found to be computationally expensive for large structures where the number of processes n becomes very large. An efficient spectral-representation-based method is proposed for the simulation of stochastic wind velocity field using Fourier-Stieltjes integral and polynomial decomposition of order q. The proposed approach is very efficient because only q×n executions of the FFT algorithm are required. Numerical investigations involving the simulation of stochastic wind velocities along the deck of a bridge show that the order of the polynomial decomposition q is very small compared to the number of processes n, and more than 5% of computation time can be saved for the simulation of 1 processes.