Dynamics of dispersion of coaxial SH-waves in a pre-stressed piezo cylindrical column, with ideal and non-ideal coatings of epoxy graphite, zinc and isotropic layers

<title>Abstract</title> <p>In this study, propagation of circumferential SH-waves in a composite cylindrical column consisting of a pre-stressed piezoelectric core surrounded by perfectly and imperfectly bonded layers has been studied. For this purpose, three different types of coating materials, namely, epoxy graphite (orthotropic), zinc (transversely isotropic), and isotropic materials have been considered. Inclusion of imperfect interface is done to make the model more practical since it accounts for the physical and mechanical discontinuity at the interface of adjacent layers. The governing equations have been established in cylindrical coordinates based on electromechanical interaction, material anisotropy, and initial stress. Analytical solution has been obtained employing the method of separation of variables resulting in Bessel function solutions. Dispersion equation for SH-wave propagation is developed using the boundary and imperfect interface conditions. Results have been illustrated numerically to analyse the impact of piezoelectric constant, dielectric constant, initial stress, and radius ratio on phase velocity for the chosen coating materials under perfect and imperfect interface conditions. It has been found that these parameters affect the dispersion properties and the phase velocity increases with an increase in their values.</p>