Research On Structural Fractal Design And Simulation Analysis Of Noise Energy Collector Based On Piezoelectric Effect

In recent years,China has made remarkable achievements in industrial development,and our daily life has become convenient and quick.But the noise problem from industrial development also brings people more and more trouble.Therefore,the noise management has become a hot issue for lots of scientists and scholars.The traditional research direction for noise control is to cut off the noise source,isolate the noise transmission path and protect the noise victims.The recent method by harvesting noise to reduce noise is a novel,leading-edge research direction for noise control.However,the existing noise collector can only collect the noise near its natural frequency,which is only suitable for collecting the noise of single frequency,and cannot show a good effect for the noise of wide band frequency,so the efficiency is lower.It has been shown that the fractal structure has been applied to the collection of broadband vibration energy and gained a good result.In order to explore the structure suitable for collecting broadband noise energy,this paper draws on the scheme of collecting the broadband vibration energy by fractal structure in the past and also introduces the collector with the fractal features into the noise energy collection.With the increase of fractal series,fractal structure has the characteristics of reducing its own natural frequency and narrowing the frequency interval between different modes.Because of these characteristics,the structure facilitates can collect the broadband vibration response easily.The tree-fractal structure is relatively simple and easy to build model,its response to broadband vibration excitation also has the characteristics of general fractal structure.Therefore,in this paper,the tree-fractal structure is used as the noise collection device to study the vibration response under random excitation of wide frequency noise.In the study,the point sound source is excited into the model to explore its response to the broadband random excitation.The numerical simulation results show that the fractal structure has a resonant response at multiple frequencies under the random excitation of broadband noise,which increases the noise recovery efficiency greatly than the before noise collector at a single frequency point.Therefore,the fractal structure feature model can effectively collect broadband noise and is a potential collection device for broadband noise.