Stiffening and damping capacity of an electrostatically tuneable functional composite cantilever beam

Abstract

The damping capacity of a novel composite film, designed to exhibit high dielectric strength and a high friction coefficient for an electrostatic tuneable friction damper, is tested on a cantilever beam. Such a system consists of a carbon fibre reinforced polymer stiffening element which is reversibly laminated onto a host structure with a dielectric material by means of electrostatic fields. Damping is achieved when the maximum shear at the interface between the stiffening element and structure exceeds the shear strength of the electrostatically laminated interface. The thin films tested consist of barium titanate particles and alumina platelets in an epoxy matrix. Their high dielectric constant and high coefficient of friction compared to a commercial available polymer film, polyvinylidene fluoride, lead to a reduction of the required electric field to stiffen and damp the cantilever beam. Reducing the operating voltage affects different aspects of the studied damper. The cost of possible applications of the frictional damper can be reduced, as the special components necessary at high voltages become redundant. Furthermore, the enhanced security positively affects the damping system’s appeal as an alternative damping method.

A novel concept for adaptive friction damper based on electrostatic adhesion

“…Agrawal and Yang proposed an electro-magnetic friction damper for seismic-excited structures using an electromagnetic field to control the normal force across two plates and proved numerically that the semi-active control of the damper outperforms a passive friction damper [27]. Ginés et al investigated the damping properties of a multi-layered cantilever beam with variable stiffness and showed how electrostatic forces can be used to reduce costs and broaden the field of application of friction damping [28].…”