永久磁石受動形2次元磁気ダンパのモデリング

抄録

An approach is presented to the modeling of a two-dimensional permanent-magnetic passive damper proposed before. For the magnetomotive force caused by the displacement of a moving core, Maxwell's equations are solved with the Laplace transforms under some assumptions that simplify the equations to obtain an analysical solution. The distribution of the incremental magnetic intensity gives the incremental magnetic flux density around the moving core, and thus relates the displacement to the net force on the moving core. The tranfer function between the net force and the displacement defines the magnetic stiffness that is a complex number with positive real and negative imaginary parts when evaluated in frequencies. The magnetic stiffness is first derived with Bessel's functions of complex numbers, and then simplified with a hyperbolic function of complex numbers and a very simple form in higher frequencies. The numerical result is checked in good agreement with experimental results.