Investigate the Pinning Effect of Ferro-Damp Induced by Non-uniform Magnetic Field

摘要

Under the non-uniform magnetic field, the pinning effect of ferro-oscillation is investigated in this study. Here the so called "magnetic pin" used to reduce seismic wave is found to occur at the position of the maximum field intensity induced. And which just bears a resemblance to be a standing point of ferro-wave or a pivot in leverage mechanism. In addition, vibrating amplitude of ferro-fluid related to magnetic field density and oscillating frequency will be also examined. Here the Diesel oil-based ferro-fluid of volumetric concentration φ = 0.01, a commercial product containing magnetite of micro-crystals about 100 nm sizes, is purchased from Matsumoto Co. While working oscillating frequency, 0-2.4 Hz, is subjected, both experimental and calculating results, estimated from the peak field intensity of 128 and 200 mT, are found to be consistent, where individual fluctuating amplitude, 1.0 and 0.8 mm will be assessed at testing spot with 1.2 cm deviated from magnetic pin. Even the higher magnitude, 1.4 mm, will be experienced if the shift of magnetic pin, induced by weaker field density, is conducted. Besides, the further augment of periodical shaking degrees at other point could be also successfully predicted based on the images captured by digital video-camera in this study.