FLUCTUATING WIND SPEED NUMERICAL SIMULATION OF U-SHAPED AQUEDUCT BASED ON ARMA MODEL

摘要

The large-span U-shaped aqueduct belongs to the windsensitive structures. Its analysis of the windinduced dynamic response is one of hot issues in the wind engineering field recently. Time domain analysis is regarded as one of the better methods to analyze the wind-resistant aspect. Research may gain an insight into the dynamic characteristics of vibration of structures under wind loads via the wind-induced response time domain analysis. Samples of wind speed time series are necessary when time domain analysis is conducted. Reproducing samples of wind speed time series by computer numerical simulation is a better method which is usually applied. Wind field acted on structures is random in both time and space. And based on the condition that aqueduct structure is always large scale and complication, the numerical simulation of its fluctuating wind speed series has a certain difficulty. The main objective of the present paper is to simulate the fluctuating wind speed time series of U-shaped aqueduct with resorting to Autoregressive Moving Average (ARMA) method. This method deduces fluctuating wind speed of every space point based on known power spectrum of the fluctuating wind speed by the transfer function. And it is efficient in simulating wind speed time series which has time and space correlativity. At the last part, it verifies the feasibility of wind speed time series simulation based on the ARMA model by presenting comparison of values of power spectrum of the fluctuating wind speed and correlation functions between target and simulation.