The central wavelength of the first Bragg scattering bandgap is approximately twice that of the lattice.Therefore,a low-frequency Bragg scattering bandgap with a small structural dimension for phononic crystals is dif...The central wavelength of the first Bragg scattering bandgap is approximately twice that of the lattice.Therefore,a low-frequency Bragg scattering bandgap with a small structural dimension for phononic crystals is difficult to obtain.In this study,a folded S-type periodic structure is developed to reduce the dimension in the direction of vibration suppression by folding unit cells.According to the foregoing,an improved folded S-type periodic structure with different unit cell arrangements is designed to widen the bandgap frequency range.Energy band diagrams and frequency responses are calculated based on the Bloch theory and using the finite element method.Furthermore,a prototype of the improved folded S-type periodic structure is fabricated using a three-dimensional printing technique,and a vibration experiment is conducted.To verify the vibration reduction performance of the structure,numerical simulation and experimental results are compared.This type of folded periodic structure can effectively reduce dimensions to satisfy the dimension requirements pertaining to the direction of vibration suppression.Hence,the foregoing can aid in promoting the use of elastic bandgap structures in engineering.展开更多
基金supported by the National Natural Science Foundation of China(Nos.12072086,12211540384 and 11761131006)the Fundamental Research Funds for the Central Universities(No.3072022CF0203).
文摘The central wavelength of the first Bragg scattering bandgap is approximately twice that of the lattice.Therefore,a low-frequency Bragg scattering bandgap with a small structural dimension for phononic crystals is difficult to obtain.In this study,a folded S-type periodic structure is developed to reduce the dimension in the direction of vibration suppression by folding unit cells.According to the foregoing,an improved folded S-type periodic structure with different unit cell arrangements is designed to widen the bandgap frequency range.Energy band diagrams and frequency responses are calculated based on the Bloch theory and using the finite element method.Furthermore,a prototype of the improved folded S-type periodic structure is fabricated using a three-dimensional printing technique,and a vibration experiment is conducted.To verify the vibration reduction performance of the structure,numerical simulation and experimental results are compared.This type of folded periodic structure can effectively reduce dimensions to satisfy the dimension requirements pertaining to the direction of vibration suppression.Hence,the foregoing can aid in promoting the use of elastic bandgap structures in engineering.
