The strain amplitude dependent damping in iron

Abstract

Abstract The strain amplitude dependent damping in pure polycrystalline iron has been determined as a function of grain size at a frequency of approximately 1 HZ, and has been shown to consist of two stages. At low strain amplitudes the damping follows the Granato–Lucke law but at higher strain amplitudes the damping can be explained in terms of the model postulated by Peguin, Perez and Gobin (1967). The strain amplitude at which stage one gives way to stage two decreases with increasing grain size. From an analysis of the second stage of damping an activation volume of 1·3 × 10−21 cm3 has been calculated.