Ultrasonic wave propagation in randomly layered heterogeneous media

• DOI: 10.1016/j.wavemoti.2023.103138
• Publication Date: 2023-04-04T00:58:43Z
• Authors: Alistair S. Ferguson; Anthony J. Mulhol...; Katherine M.M. Tant; Mohammud Foondun
• Keywords: Slowness; Orthotropic material; Reflection; Reflection coefficient; Transmission coefficient

This article considers the propagation of high frequency elastic waves in a layered material. Each layer is locally anisotropic and thicknesses slowness surface orientations are modelled by (Markovian) process. work important deepening our understanding ultrasonic non-destructive testing carbon fibre reinforced polymer (CFRP) composites polycrystalline materials. The paper focuses on monochromatic shear propagating two-dimensional ((x1,x3) plane) heterogeneous media. displacement x2 direction model reflection transmission wave at interfaces. rotation each lies (x1,x2) plane varies with (x3) only. Expressions for local global coefficients reflected transmitted amplitudes derived shown to satisfy energy conservation. resulting stochastic differential equations lead self-adjoint infinitesimal generator which can be used produce Fokker–Planck equation study probability distribution coefficient. Explicit expressions moments distributions power then derived. dependency mean standard deviation coefficient depth penetration, localisation length, reported.