Papers Published

  1. Doke, Nitin S. and Gavin, Henri P., Non-proportional damping and semi-active control, Proceedings of the International Modal Analysis Conference - IMAC, vol. 1 (1999), pp. 431 - 436 .
    (last updated on 2007/04/09)

    Electro-rheological (ER) and magneto-rheological (MR) materials exhibit variable stiffness and damping properties when subjected to strong electric or magnetic fields. While pre-yield visco-elasticity is a very important feature of these materials when subjected to oscillatory shears, the resultant stresses are primarily dissipative. Including an ER and MR device in a lumped-parameter structure (i.e., a building frame), results in large damping forces where the devices connect to the frame. Such structures are therefore not proportionally damped. This paper examines non-proportional damping in the context of ER and MR devices for controlling base-excited structures.

    Rheology;Stiffness;Damping;Viscoelasticity;Electric field effects;Magnetic field effects;