Abstract: Unit structure model of local resonant phononic crystals is set up.The effects of array configuration, filling rate arrangement and the arrangement of scatterer thickness are studied on the sound insulation properties of non-uniform phononic crystals (NPCs) through the finite element method.So that the structure of NPCs in different frequency bands play a good sound insulation effect and reduce the local attenuation in acoustic band.When the scatterers are close to the incident direction of array configuration, the NPCs have more sound insulation.If the filling rate increases from the middle column to the both sides, the NPCs have less local attenuation.With the scatterer thickness decreasing from the middle column to both sides, the NPCs are suitable for suppressing the medium-high frequency vibration or noise.On the contrary, another arrangement structure, with the scatterer thickness decreasing from the middle column to both sides, is suitable for low frequency noise isolation.The NPCs with the aluminum vibrator, the steel vibrator or the lead vibrator have similar sound insulation properties at low frequency, and the sound frequency band at medium and high frequencies is moved to low frequency with the increase of vibrator density.The obtained results may be provided as a theoretical guidance for the NPCs playing good effect on noise reduction.

Key words: Unit structure model of local resonant phononic crystals is set up.The effects of array configuration, filling rate arrangement and the arrangement of scatterer thickness are studied on the sound insulation properties of non-uniform phononic crystals (NPCs) through the finite element method.So that the structure of NPCs in different frequency bands play a good sound insulation effect and reduce the local attenuation in acoustic band.When the scatterers are close to the incident direction of array configuration, the NPCs have more sound insulation.If the filling rate increases from the middle column to the both sides, the NPCs have less local attenuation.With the scatterer thickness decreasing from the middle column to both sides, the NPCs are suitable for suppressing the medium-high frequency vibration or noise.On the contrary, another arrangement structure, with the scatterer thickness decreasing from the middle column to both sides, is suitable for low frequency noise isolation.The NPCs with the aluminum vibrator, the steel vibrator or the lead vibrator have similar sound insulation properties at low frequency, and the sound frequency band at medium and high frequencies is moved to low frequency with the increase of vibrator density.The obtained results may be provided as a theoretical guidance for the NPCs playing good effect on noise reduction.