Analysis of elastothermodynamic damping in particle-reinforced metal-matrix composites

When a composite material is subjected to a homogeneous or inhomogeneous stress field, different phases undergo different temperature fluctuations due to the well-known thermoelastic effect. As a result, irreversible heat conduction occurs and entropy is produced. This entropy production is the genesis of elastothermodynamic damping. Recently, taking the second law of thermodynamics as a starting point, a general methodology for calculating the elastothermodynamic damping was presented by Kinra and Milligan. Using this method, we calculate the elastothermodynamic damping for two canonical problems concerning particle-reinforced metal-matrix composites: (1) a single spherical inclusion in an unbounded matrix and (2) an N layer finite concentric composite sphere. In both cases, a uniform radial time-harmonic loading is considered.