Test method for sound absorption coefficient in passenger compartment of rail train based on semi-anechoic chamber of whole vehicle

Abstract

The invention relates to a compartment sound absorption coefficient test method based on whole vehicle semi-anechoic chamber for a rail train, and belongs to the field of a compartment sound coefficient test method for the rail train. According to the method, the whole vehicle semi-anechoic chamber which can be enough to accommodate a tested single train compartment is built, a special whole vehicle semi-anechoic chamber construction index is given out, special positions and determination methods of an omnidirectional sound source, a reference microphone and a sampling point sensor array are also definitely given out, and meanwhile, an experiment formula for solving a compartment sound absorption coefficient under the whole vehicle semi-anechoic chamber environment and a solution method ofeach parameter are given out. By the train compartment sound absorption coefficient test method, the inherent problem of a standing wave method and an external reverberation chamber can be solved, aspecially-made sample is completely prevented, and the sample fabrication cost is reduced; and no harm is generated to the train, all sound absorption coefficients of a train attention region can be tested in one time, and the method has actual appliance significance to a sound absorption coefficient test experiment formula of a large space-based empty barrel structure.

Description

technical field [0001] The invention belongs to the field of testing methods for the interior sound absorption coefficient of rail train passenger compartments, and in particular relates to a method for testing the sound absorption coefficient of rail train passenger compartments based on a semi-anechoic chamber of a complete vehicle. Background technique [0002] With the development of the field of modern rail transit, the noise level in the vehicle has received more and more attention as an important indicator of comprehensive comfort evaluation. In-car noise refers to various noises that exist in the passenger compartment of the train when the train is running. How to minimize the noise level in the car and improve the ride comfort is an important factor to be considered in the development and design of modern rail train products. [0003] The use of interior materials with excellent sound absorption performance is an important measure to improve the quality of interior...

AI Technical Summary

Problems solved by technology

[0011] In order to solve the problem of establishing a reverberation field inside the structure under test and measuring the decay time of the sound pressure level inside the passenger compartment by interrupting the sound source method to derive the sound absorption coefficient, the method is only suitable for small spaces and not suitable for empty barrels inside the passenger compartment of rail trains with huge dimensions. In addition, the influence of external noise on the measurement results must be eliminated when the sound absorption coefficient test is carried out for the interior of the rail train passenger compartment. It is difficult to meet the test environment requirements in ordinary occasions, and the solution formulas and empirical parameters required for the test are not available. For reference, it is a technical problem that requires a lot of experience accumulation, groping and summarization to obtain. The present invention provides a method for testing the sound absorption coefficient of rail train passenger compartment based on the semi-anechoic chamber of the whole vehicle

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