Research On Vibration Model And Vibration Isolation Effect Of The Locally Resonant Sonic Crystal

Sonic crystal is material with elastic vibration bandgap where the propagation of vibrations is forbidden. This property provides new prospects for technology of vibration attenuation. The formation of the bandgap of locally resonant sonic crystal has great theoretical value. The lattice constant of locally resonant sonic crystal is one or two orders smaller than the wavelength of the wave which lies in the bandgap. Thus, this kind of sonic crystal has many advantages in the application of vibration absorption and noise control in low frequency.First, the basic theory, property and recent research of sonic crystal have been introduced. Based on conclusion inducted by the Professor Wen's experiment about how three components of locally resonant sonic crystal's parameter (scatterer, coating layer and matrix) influence the bandgap and the two-dimensional locally resonant sonic crystal modal which is first introduced by Martin Hirsekon, we establish the model for the starting frequency of the three-dimensional first bandgap and educe the calculation formula of the frequency. Then we use the ANSYS software to set up the 16-unit model of local resonant crystal and calculate the modal frequency and displacement-frequency curve of harmonic analysis.. In Chapter 5, we introduce the four-microphone system to measure the sound transmission of our three-dimensional locally resonant sonic crystal. In the end, a summary of our work and outlook for future works of the sonic crystals are presented.