Whole-space noise prediction method of rail transit bridge and steel rail

Abstract

The invention discloses a whole-space radiation noise prediction method of a rail transit bridge and a steel rail. The method comprises the following concrete steps: firstly, respectively establishing three-dimensional fine finite element models of a vehicle, a steel rail and a bridge, and acquiring the dynamic response of the bridge and the steel rail by means of time domain vehicle-rail-bridge coupling vibration analysis; secondly, obtaining modal acoustic vectors of the bridge and the steel rail by means of acoustic space Fourier transform, and calculating the radiation noise of the bridge and the steel rail at a near field point near a track center line by combining the dynamic response of the bridge and the steel rail; after that, respectively establishing a two-dimensional steel rail vibration acoustic coupling propagation model and a two-dimensional bridge vibration acoustic coupling propagation model, and solving the attenuation distribution laws of noise of the steel rail and the bridge at a far field point under the action of a steady-state excitation load by using an acoustic infinite element method; finally, selecting a certain near field point as a strong source point, and predicting the whole-space noise level of the bridge and the steel rail according to near field calculation results of the three-dimensional models and far field attenuation rates of the two-dimensional models.

Description

technical field [0001] The invention relates to the field of rail transit, in particular to a method for predicting the entire space of vibration radiation noise of rail transit bridges and rails. Background technique [0002] With the development of the economy, the construction speed of rail transit lines is increasing year by year. Because the cost of rail transit elevated bridges is lower than that of underground lines, elevated bridges have become one of the important forms on rail transit lines, accounting for a large proportion of the total line length. high. The vibration and radiation noise of the bridge structure caused by the passing of the train makes the noise level on the elevated rail transit line often higher than that on the ordinary line. Rail transit lines often pass through densely populated areas, and structural vibration and noise seriously affect the daily work and life of citizens, which makes the noise of rail transit viaducts an urgent problem to b...

AI Technical Summary

Problems solved by technology

[0007] (2) Establish a two-dimensional rail-bridge acoustic model, and consider the influence of the body boundary to calculate the radiated sound pressure value at the unit vibration velocity of the outer surface. The two-dimensional acoustic model adopts the boundary element method or infinite element method, and the boundary element method requires Set the CHIEF point or Burton-Miller method in the model to solve the problem that the eigenfrequency is not unique. The infinite element method needs to analyze the convergence of the radial order, radius and other parameters of the infinite element element;

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