Evaluation of the damping characteristics of a hybrid piezo-shunt nanocomposite using a two-step homogenization approach

Abstract

Composite materials containing piezoelectric particles have attracted remarkable attention because of their distinctive electromechanical conversion characteristics. These supreme properties lead to their applications in various fields, such as vibration damping of structures. The damping parameter of dynamic systems is crucial, especially when they undergo resonance phenomena. Multi-phase polymer matrix composites consisting of piezoelectric particles are innovative material systems that have been recently introduced to convert the mechanical vibrations into electrical energy, and subsequently dissipate into heat through an internal electrical circuit. The present study aims to analytically investigate the viscoelastic characteristics of a shunted three-phase composite composed of a polymer matrix, electrically conductive nanoparticles and piezoelectric particles. The effective viscoelastic characteristics of a shunted composite are calculated using one- and two-step homogenization procedures and by considering the viscoelastic characteristics of constituent materials. The influence of several key parameters, namely, the non-dimensional frequency, the volume fraction of electrically conductive nanoparticles and piezoelectric particles, and the shape of the inclusions, on viscoelastic characteristics, such as phase angles, the storage modulus and loss modulus, are examined. The viscoelastic characteristics are considerably affected by these parameters, and the perceived behavior is justified by the governing equations. The assessment of results confirms that the damping characteristics can be improved by careful selection of a volume fraction of constituent materials and control of the excitation frequency of the smart composite, while avoiding additional costs and likely inconveniences in the fabrication process.