Discrete element method model of electromagnetic particle damper with a ferromagnetic end cover
Particle damping technology is a passive vibration control technology and can be used in harsh environments such as high temperature and bitter cold. However, particle dampers (PDs) are out of function in the abnormal physical environments such as the micro-gravity condition and the centrifugal load filed due to their structure and damping mechanism, thus the applications of PDs in these environments are limited. In order to conquer the negative effects of the abnormal physical fields, the magnetic force is introduced to improve the damping effect of a PD by using the electromagnetic field. The relationship of the magnetization of the ferromagnetic particle and the intensity of the applied magnetic field is derived based on the Ampere’s circulation theorem. The magnetized particle is considered as a magnetic dipole, and the magnetic force between particles is studied. Then the magnetic field in the electromagnetic coil with a ferromagnetic end cover is analyzed, the magnetic force on the particles caused by the magnetic field is expressed as a formula. The DEM model of an electromagnetic particle damper with a ferromagnetic end cover (EPDF) is obtained accordingly, which is verified by comparing with test data. Moreover, the effects of electric current on the damping performances of EPDFs are studied. Through the control of current, the EPDF can be used in the abnormal physical environments mentioned above, and the damping performances of EPDFs in these environments will be investigated in the further work.
Keywords: Particle damper, Ferromagnetic end cover, Magnetic dipole, Magnetic field, DEM,