Design And Vibration Reduction Of Novel Two-Dimensional Chiral Phononic Crystals

The rapid development of various industries has greatly increased the need for adverse vibration and noise control.More and more new situations require vibration reduction and noise reduction,especially to create a wide frequency range of vibration reduction environment at low frequencies.In order to achieve a wider vibration suppression range at low frequencies,a series of designs and studies have been carried out on the gap characteristics in this paper,which combines the plane wave expansion method and the finite element method,based on the wave transfer theory in elastic dynamics and the lattice and energy band theory in solid physics.The paper mainly designs a new two-dimensional chiral phononic crystal structure,and studies the wave propagation characteristics of the new two-dimensional three-ligament,four-ligament and six-ligament new chiral structures,as well as the relationship between its geometric key parameters and the band gap characteristics,and geometrically optimize of the structure.In addition,three novel two-dimensional chiral phononic crystal structures were combined to obtain a combined phononic crystal structure.The energy band structure of the combined structure and the relationship between the combined structure and its basic chiral structure were analyzed.The research shows that the new two-dimensional chiral phononic crystal structure proposed in this paper has good wave attenuation ability and can suppress the wave propagation well in the band gap range.The band gap characteristics of the new structure are also affected by many factors.Among them,the increase of the number of ligaments will reduce the band gap,the increase of the rotation angle of the chiral structure within a certain range will reduce the practicability of the band gap characteristics,and the increase of the filling rate will reduce the practicability of the band gap characteristics.The band gap position of the structure is developed to a lower frequency and the band gap width is wider,but the relationship between the energy band structure of the combined structure and the energy band structure of the basic chiral structure is not clear.In this paper,the research work on new chiral phononic crystals has carried out a beneficial exploration for realizing vibration reduction in a wide frequency band at low frequencies,which has a certain guiding role for practical engineering applications.