Structure improving low frequency sound absorption performance through magnetism

Abstract

The invention discloses a structure improving low frequency sound absorption performance through magnetism. The structure comprises two identical lateral supports perpendicular to the wall surface anda mechanical impedance plate parallel with the wall surface, wherein the wall surface, the mechanical impedance plate and the two lateral supports form a square resonant cavity, the resonant cavity is internally provided with a pair of magnetic material blocks, one magnetic material block is fixedly connected with the wall surface, the other magnetic material block is fixedly connected with the mechanical impedance plate, the two magnetic material blocks are arranged face to face, the sizes of the magnetic material blocks are identical, polarities of the magnetic material blocks are opposite,and a viscoelastic material ring is adhered between the two lateral supports and the mechanical impedance plate. The attraction force of the magnetic material blocks is the same as the sound pressurein the direction and is opposite to the elastic force of the viscoelastic material ring, the magnetic force generated by the magnetic material blocks counteracts a part of the elastic force of the viscoelastic material ring, the elastic force of the elastic material ring is reduced, and the low frequency sound absorption performance is improved.

Description

Technical field [0001] The invention belongs to the field of noise control, and particularly relates to a structure with sound absorption performance, which can absorb low-frequency noise below 500 Hz. Background technique [0002] Commonly used sound-absorbing materials for noise control structures are: glass wool, slag wool, rock wool, foam plastic, asbestos wool, felt, soft fiberboard and other porous sound-absorbing materials. Generally, porous sound-absorbing materials have good medium and high frequency absorption. Acoustic performance, but poor low-frequency sound absorption performance. The sound absorption structure of the micro-perforated plate is also often used for noise control. Its sound absorption mechanism is cavity resonance, which also has the problem of poor low-frequency sound absorption performance. In order to improve the low-frequency sound absorption, a method of thickening the sound-absorbing material layer is required. For the micro-perforated plate str...

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to solve the problems existing in the existing noise control structure, and to provide a structure that uses magnetism to improve low-frequency sound absorption performance, which can reduce the elastic coefficient of mechanical impedance without reducing its damping coefficient. Low frequency has high sound absorption coefficient and good sound absorption bandwidth

Images