Study On Vibration Reduction Performance Of Deformable Acoustic Metamaterial Plate

Acoustic metamaterials are a cyclical artificial composite structure in recent years.Negative equivalent parameters appear in some special frequency bands,which are called bandgap.The presence of bandgap makes the acoustic metamaterials have obvious advantages over low noise reduction compared to conventional sound insulation materials,but there is also a narrower band gap problem.In the development of acoustic metamaterials,the characteristics of the acoustic metamaterial plate due to its light weight,can be carried and easy to get negative equivalent parameters have been widely concerned and have been developed in recent years,but the band gap is narrow The problem still exists.In this paper,a scheme of deformable acoustic metamaterial plates is proposed to study how to improve the frequency band gap of acoustic metamaterials by using mass deformation and to explore the relationship between band gap and its damping performance.This is helpful to promote the vibration The development and application of the field is of great significance.Firstly,the finite element software is used to simulate the energy structure and vibration transmission loss of the acoustic metamaterial plate before and after the deformation of the mass block.It is found that the deformation of the mass block can shift the position and width of the band gap,the ultra-material plate has a strong attenuation ability for the frequency band in the bandgap,and there is a correspondence between the frequency band gap and the vibration performance.The influence of the pre-stretching amount of the rubber film and the attachment area of the mass on the bandgap position and width of the acoustic super-material plate is analyzed,and the scheme is improved and optimized according to the change rule.Then,the viscoelastic constitutive model of the rubber is described by the fractional Kelvin-Voigt model.The vibration equation of the rubber film is regarded as a viscoelastic rectangular plate,and the analytical solution of the vibration equation is obtained.The experimental results show that the elastic modulus of the rubber film increases with the increase of the vibration frequency,and the band structure of the acoustic metamaterial plate is simulated and analyzed.It is found that with the increase of the elastic modulus of the film,The position of the band gap will become high,the width of the band gap will become smaller and smaller.Finally,two acoustic metamaterial plates were fabricated according to the design scheme to simulate the state of the mass before and after the deformation,and the vibration experiment was carried out,and the corresponding frequency response curve was obtained.The experimental results show that the damping capacity of the mass after deformation is stronger than that before the deformation of the mass block,and the vibration in the band gap is strong.