Mechanism Of Energy Transmission Control In Structures Based On Piezoelectric Transducers

Vibration energy, which widely exists in the environment, propagates in the medium as a form of waves. The structure-bone vibration in precision instruments and equipment may significantly reduce the precision of devices. The stronger vibration may even cause permanent damage. Vibration energy from sources passes through the propagation path and reaches the receiver. So via reducing the vibration in the source and path, the vibration problem in the receiver can be solved. Generally, source control is the most effective method to control vibration, but the source usually can’t be changed so that such method is infeasible. Therefore, in many practical applications, the propagating path control is the only effective way to suppress the vibration energy. In order to solve the energy source of active control and the adaptation of passive control, semi-active control becomes the focuses of vibration control. Piezoelectric materials are very suitable for the applications in active and semi-active control of energy delivery paths due to its excellent characteristics of electromechanical energy conversion.However, the research based on the piezoelectric effect of semi-active control for energy transfer is now mainly focused on the numerical simulation. Such research does not clearly reveal the relationship between mechanical, electrical and energy propagation. Therefore, in order to get the relationship and reveal its mechanism, a basic structure- beam is chosen to analyze the bending wave and establish the general energy transfer model of active control. The general rule of beam energy transmission control is summarized. And then a general passive system of energy transfer model is built to analyze the relationship between the mechanical parameters and energy transfer. The mechanical parameters of a piezoelectric transducer can be changed via circuits. Based on such characteristic, an energy transfer control model with piezoelectric system is built to analyze the mechanical parameters and energy transfer effect in terms of circuit. At last an active and a passive control experiment are performed in a long beam and get good results. But the result of the piezoelectric experiment in a small beam is not good enough due to the poor signal to noise ratio in the small beam. From the experimental results, it can be concluded that the circuit does changes system performance. By improving the analysis model, the theory curve can be more matches with the experimental results.This research has produced some preliminary results on the mechanism study, but deep exploration is still necessary. In the research a general method is proposed to get the mechanical parameter to suppress the vibration energy transmission in beams passively. Based on the piezoelectric effect, the control frequency bandwidth can be changed to achieve semi-active control.