Study on band gap characteristics of three-dimensional periodic structure wave impeding block
The wave impeding block(WIB)is commonly used to control vibration pollution caused by vibration sources such as power machines,rail transit,and construction.However,the WIB is limited by the cut-off frequency of soil layer,resulting in a narrow vibration isolation frequency band,making targeted vibration isolation in a specific frequency range difficult.Based on the principle of phononic crystal,a three-dimensional periodic structural wave impeding block(PSWIB)is proposed.The band gaps of the three-dimensional PSWIB with cube and sphere scatters are calculated using the COMSOL finite element method.The effects of structural and material parameters on band gap characteristics are discussed,and orthogonal test optimization design is conducted.Both theoretical and numerical calculation show that the attenuation zone obtained by the three-dimensional finite periodic structure wave impeding block is consistent with the band gap range of the infinite periodic wave impeding block,which has band gap.The maximum amplitude attenuation in the vibration attenuation zone can reach 54 dB.Compared to traditional wave impeding block,the three-dimensional periodic structure wave impeding block broadens the vibration isolation frequency band,overcomes the cut-off frequency limitation,and allows for the design of material parameters based on the vibration source characteristics to meet target frequency isolation requirements.