Damping effect of multi-layer beams with embedded electro-rheological fluid

The damping effect of multi-layered composite beams with embedded ER fluid layers is investigated. A three-layer beam was composed of the aluminum lay ers bonded together by silicone rubber with an internal cavity filled with ER fluid. The damping factor of the beam can be controlled by the voltage b etween the elastic layers. To increase the damping effect, an inner layer w as inserted into the cavity so that the composite beam consists of three el astic layers and two ER fluid layers. The frequency characteristics of the three-layer beam and the five-layer beam were investigated experimentally a nd numerically. The results show that the damping factor of the composite b eams can be considerably raised by increasing the electric field. The natur al frequency of the beams increases with the field due to the variation of stiffness of the ER fluid layers. The influence of size of inner layer on t he damping effect of the five-layer beam was also investigated. It is shown that the damping factor of a five-layer beam could be larger than that of a three-layer beam if the size of the inner beam is appropriately designed.