Two-dimension phonon structure of scatterer with gap characteristic and material with gap composed by the same

Abstract

The invention provides a two-dimensional phonon structure provided with lacune feature scatterers and a band gap material of the structure. Under the condition that the parameter condition (such as lattice constant, material component etc.) does not change, a strip or more strips of hair cracks used for sound absorption are opened on the scatterer. The acoustic band gap characteristics with relatively wide band gap and relatively low initial frequency can be realized by adopting the structure. Compared with the prior two-dimensional phonon structure with the acoustic band gap characteristics,under the condition of keeping the original parameters of phononic crystals unchanged, the structure of the invention fulfills the purpose of widening the range of band gap and reducing the initial frequency of band gap through opening cracks on the scatters. On the basis of Bragg scattering and local resonance principles, a hair crack anechoic mechanism is added and the initial frequency and width of the band gap are adjusted by changing the parameters (number, width and position) of cracks, thus obtaining better acoustic band gap characteristics compared with the original phonon structure.

Description

technical field The invention belongs to machinery, and specifically relates to a two-dimensional phonon crystal structure and a bandgap material with gap characteristic scatterers, which are applied to acoustics, urban environment, industrial noise control and aviation noise control. Background technique In urban and industrial noise control, the classic sound absorption and sound insulation technologies are still mainly used at present, such as designing sound insulation structures according to the mass theorem. Since the 1990s, with the discovery and development of phononic crystals, people began to pay attention to the application of phononic crystal technology to design and prepare sound insulation structures with acoustic band gap characteristics. In phononic crystals, by increasing the density ratio, sound velocity ratio, physical parameter ratio (elastic modulus, etc.) The absorption layer and other methods are used to obtain a certain range of acoustic band gap or ...

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