Method for calculating acoustic scattering coefficient of periodic structure plate based on mesh-free model

Abstract

The invention discloses a method for calculating an acoustic scattering coefficient of a periodic structure plate based on a mesh-free model. The method comprises the following steps: firstly, deducing a system equation which is suitable for calculating sound pressure of nodes of a periodic structure plate; and then, modeling the periodic structure plate and a reference plate of the same dimension through the nodes, and using a moving least square method to construct a shape function; finally, combining the system equation with the shape function to acquire the sound pressure difference at the nodes, so that sound pressure of a receiving point is calculated, and a direction scattering coefficient and a mean scattering coefficient are calculated. According to the method disclosed by the invention, a mesh-free method is introduced to calculate a numerical value of the acoustic scattering coefficient of the periodic structure, so that a series of problems caused by existence of meshes in a conventional numerical method are avoided. The method has good adaptability, and can locally increase node density without re-distributing the model when frequency upper limit is needed to be calculated. Compared with measurement experiment, the method has high precision, and has an extensive application prospect in the calculation of the scattering coefficient value 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 based on a gridless model, 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 scat...

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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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