Method for calculating acoustic scattering coefficient of periodic structure plate

Abstract

The invention provides a method for calculating an acoustic scattering coefficient of a periodic structure plate. The method comprises the following steps of: deducing a system equation suitable for the node sound pressure calculation of the periodic structure plate; on the other hand, modeling the periodic structure plate and a reference plate with the same size as that of the periodic structure plate by utilizing nodes; then establishing a shape function by virtue of a movable least square method; and after combining a periodic structure plate node model and a reference plate node model to obtain sound pressure difference at the nodes, solving the sound pressure of a receiving point and further solving a direction scattering coefficient and an average scattering coefficient. According to the method provided by the invention, a grid method is introduced into acoustic scattering coefficient numerical calculation of the periodic structure, so that a series of problems caused by the grids in a traditional numerical method can be solved. The method provided by the invention is good in adaptability, and can be used for locally increasing the node density without repartitioning the model when the calculated frequency upper limit is required to be improved. Proven by measurement, experiment and comparison, the method has the advantages of high precision degree and wide application prospect in numerical calculation of the scattering coefficient of the periodic structure.

Description

technical field [0001] The invention relates to the technical field of acoustic scattering, in particular to a method for calculating the acoustic scattering coefficient of a periodic structural plate, which is applied to calculating the acoustic scattering coefficient of a periodic structural plate of any shape. Background technique [0002] The periodic structure is a special interface sound scattering structure, which refers to the structure in which the geometric shape of the material is arranged according to the periodic rules in the macroscopic space. The periodic structure has already existed in form and is widely used because of its good sound diffusion performance. It is mostly used in concert halls, recording studios, theaters and other places that require high sound field diffusion. The key to the application of periodic structures is the acquisition of their scattering coefficients. There are usually two ways to obtain the acoustic scattering coefficient, one is...

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Problems solved by technology

[0003] At present, the numerical calculation of the scattering coefficient mainly adopts grid-based methods such as the boundary element method. Due to the existence of the grid, these methods have some inherent defects: firstly, the pre-processing is difficult, and the grid model must be generated before the calculation, so that the data preparation The workload is heavy, especially for relatively complex structural models, which are prone to distorted meshes; second, this type of method generally uses low-order polynomials as the interpolation function of the sound pressure function, and it is impossible to give a good solution to the problem of higher-frequency sound wave propagation. Approximation; Third, the calculation result is not smooth and continuous, and smoothing post-processing is required

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