A study of damping characteristics of alumina-filled epoxy nano-composites

Abstract

Damping behavior of polymeric composites with nano structured phases is significantly different from usual polymer composites. Viscoelastic homopolymers exhibit high material damping over a relatively narrow range of temperature and frequencies. In many practical situations a polymeric structure is required to possess better strength and stiffness properties together with a reasonable damping behavior. Viscoelastic polymers show higher loss factor beyond the glassy region which comes with a significant drop in the specific modulus. Addition of nano alumina particles to epoxy leads to improved strength and stiffness properties with an increase in glass transition temperature while retaining its damping capabilities. Experimental investigations are carried out on composite beam specimen fabricated with different volume fractions of alumina nano particles in epoxy to determine loss factor, tan δ. Impact damping method is used for time response analysis. A single point Laser is used to record the transverse displacement of a point on the composite beam specimen. Experimental results are compared with theoretical estimation of loss factor using Voigt estimation. The effect of interphase is included in theoretical estimation of loss factor. Passive vibration suppression may be introduced in the polymeric structures along with improved structural properties by tailored dynamic characteristics using nano alumina particle filled epoxy composites.