Szary M.

Succesfull applications of rheological fluids changed classical damper characteristics with uncontrolable viscosity fluid by introduction of controlable viscosity fluids. Changes in viscosity affect damping constant, therefore, behavior of mechanical system can be controled by variable damping force or variable damping torque. Internal combustion engines and other machines use torsional vibration damper for limiting amplitudes of vibration at critical velocities. The design of this type of absorber consist of flywheel with friction rings that are free to rotate on the shaft and springs under tension to generate friction between a flywheel and friction rings. When an amplitude of torsional vibration increases, the flywheel do not follow the shaft oscillations and energy is dissipated by friction due to relative motion. The springs tension becames a critical parameter in effective energy dissipation process. The second design is known as a untuned viscous vibration damper. In this damper a torque results from the viscosity of fluid within the flywheel cawity and relative motion. This particular design can find a wider range of applications by utilization of rheological fluids with a controlable viscosity. In this paper discrete models of mechanical systems performing translation and torsional motion with controled damping are discussed. The modeling indicate that rheological fluids can be effectively applied to control unwanted vibrations in mechanical systems.