Dynamics of magnetic bead chain in magnetic field

Experimental and numerical investigations have been carried out on dynamics of magnetic bead chain in magnetic field. By the observation of vibration of chains formed on a solenoid coil, resonant frequency of the chains and equivalent stiffness were estimated. It was deduced that the resonant frequency was irrelevant to magnetic field, while the equivalent stiffness depended on magnetic field. From the numerical study using Distinct Element Method, it was also shown that the equivalent stiffness increased with the increase in magnetic field and decreased with the increase in chain length. Experimentally observed dependency of stiffness on magnetic field was explained as the combined effect of both magnetic field and chain length.