Research On The Active Vibration Control And The Active Magnetic Constraining Layer Damping Treatments For Beams

The technique of active vibration control has been studied deep and widely since 1950s. The technique of active and passive magnetic constraining layer damping (APMCLD) treatment which is a new-developed control method, has got a lot of theoretic productions. However, we still have not enough experimental production.In this paper, we first obtained the motion equations of a cantilever beam, then we analysed it with the Newmark method. And we also used Matlab simulating the vibration of a cantilever beam which is under PID control. We introduced a linear-search method to PID control, which can make the parameters of PID control optimized automatically. Comparing the phasic chart of input signal, respond signal and perfect feedback signal, we developed a preferably method to solving the lag problem of the factual feedback signal which will result the partial failure. The amelioration reduced a lot of dependence between the algorithm and structural character. The improved PID method has a great increase in damping efficiency.Base on the theory of computer control, we designed a experiment platform, and experimentalized many times. Within pre-treatment and post-treatment, we obtained some preferable results, which proved that the PID control is a effective control method in fact. To a single-input and single-output vibration system, the factual damping efficiency of our control system can attain to about 72.58%, while the amplitude will reduce about 42%.The result of the experiments shows that, the bigger difference between excitation frequency and resonance frequency, the faster the damping efficiency reduced. In addition, because of inherent error, we have to enhance the sampling frequency to get a better control effect, however we need some better hardware at the same time.Then, with a brief systematic review on the headway of MCLD methods, the differential equations of motion were derived by employing Hamilton's principle. Then we got the vibration attenuation mechanism of MCLD. Base of our experiment, we discussed some problems which will be appeared when we design a experiment platform for APMCLD. We hope that the discussion will give a correct direction for the experimental study of MCLD.Finally, we gave a summary, which pointed out the advantage and disadvantage of our improved algorithm. We also pointed out that experiment is the most important thing in the research on APMCLD at the present time. Making a lot of experiment may give us some new ideas.