Dynamic analysis of a new autoparametric pendulum absorber under the effects of magnetic forces

Abstract

Autoparametric pendulum absorber is an effective device to suppress vibrations and has been used widely in many fields of engineering. However, the vibration absorption of the conventional pendulum absorber is effective only in a small bandwidth. To tackle this problem, a novel model of the autoparameteric absorber with attached magnets is proposed in this paper. Under the effects of the attractive magnetic forces produced by the magnets, the pendulum will absorb more vibration energy of the primary system. In this way, the performance of the pendulum absorber can be improved. In this research, the dynamic response of this new system is studied analytically and the vibration absorption performance is analyzed. Firstly, the magnetic forces produced by the permanent magnets are investigated analytically and the results are validated numerically. Then the response of the system is analyzed using the method of varying amplitudes and the results are validated by a numerical method. The optimal values of the parameters of the absorber are studied by using the small parameter expansion method. Finally, the optimal performance of this new absorber is analyzed, including the vibration amplitude of the hosting structure and absorption bandwidth. The results show that the vibration amplitude of the hosting structure is smaller and the absorption bandwidth is larger as compared to the conventional pendulum absorber.