The Design Of Dynamic Vibration Absorbers And The Research Of The Low-frequency Sound Isolation Technology On Thin Plate

The rapid development of high-speed railway has brought great convenience to people’s travelling. But the attendant noise problem has increasingly caught our eyes. Traditional acoustic technology works well for the high-frequency. But its performance for low-frequency noise control is not that good as we expected, particularly in the application of the sheet structure. So we need to have a breakthrough based on the traditional acoustic technology. Active sound insulation technology is thus introduced as an innovation which can be a good supplement for the deficiency of the controlling low-frequency noise on traditional acoustic technology.This paper is to study the acoustic insulation technologies based on dynamic vibration absorber. The first step is analyzing the properties of the thin plate according to the theory and simulation and finding the design method of dynamic absorber absorber’s parameter. After that, the first generation of dynamic absorbers is designed and the parts of the dynamic vibration absorber are processed and assembled. In order to verify the performance of the acoustic insulation technologies based on dynamic vibration absorber, we will do active acoustic insulation experiments on a thin plate experimental platform in an anechoic-reverberation chamber. The results showed that the acoustic insulation technologies based on dynamic vibration absorber can effectively improve the performance of the sound insulation of the thin plate. According to the observation during the experiment and the analysis of the experimental results, we find the drawbacks of the first generation of dynamic vibration absorber, and then optimizing the structure of the second generation of dynamic vibration absorber. In order to get a wider control frequency band, the second generation of dynamic vibration absorber is designed not only by using four-oscillator system,but also by the damping structure. By simulating, we find that the acoustic insulation technologies based on the second generation of dynamic vibration absorber can effectively improve the performance of the sound insulation of the thin plate in band100-200Hz.Finally, this paper also do an acoustic simulation for the thin plate which installed the second generation of dynamic vibration absorber,and then attach the viscoelastic material block and steel plate to the thin plate, the simulation results show that the sound insulation of the thin plate is further promoted by this method.