Transient Response of Sandwich Beams with Electrorheological Core

The present work investigates the transient response of a three-layer sandwich beam with an electrorheological ( ER) core. Electrorheological fluids are a class of smart materials, which exhibit reversible changes in mechanical properties when subjected to an electric field. As applying an electric field to the core layer changes the dynamic characteristics of the structure, the ER layer can be used for suppressing the vibrations and reducing the settling time of the beam. A finite element model of the structure is developed and a direct integration algorithm is used to simulate the impulse response of the proposed sandwich beam. The core is modeled as a Bingham plastic material and effects of changes in the applied electric field on the structure settling time and its natural frequencies are represented for several thickness ratios. The variations of damping force vector, due to the dependence of the ER fluid shear stress, to the sign of shear rate, are considered in each iteration. The ER layer thickness and the applied electric field level have a significant influence on the damping behavior of the model.