Improved damping in sandwich beams through the inclusion of dispersed graphite particles within the viscoelastic core

Abstract

In this work, the passive damping in a sandwich beam is investigated for the inclusion of dispersed graphite particles within the viscoelastic core. The effective material properties of the viscoelastic particulate composite (VEPC) are estimated using a differential scheme and the elastic–viscoelastic correspondence principle. The corresponding results reveal increased effective storage moduli and decreased effective loss factor of a viscoelastic medium for the inclusion of graphite particles. As it implies both the possibilities of augmentation and deterioration of passive damping in the sandwich beam, the subsequent study is carried out on the variation of damping characteristics of the sandwich beam especially for different volume fractions of inclusion. It is found that the passive damping in the sandwich beam increases significantly for the inclusion of graphite particles within the viscoelastic core, and also an optimal volume fraction of inclusion corresponding to the maximum damping in the sandwich beam appears. Further study on the optimal utilization of VEPC patches within the core of the sandwich beam reveals a minimal change of weight of the overall beam for the replacement of patches of conventional viscoelastic material by VEPC patches while this replacement yields a remarkable improvement of passive damping in the sandwich beam.