Nondestructive Characterization of Composite Media

About this book

The basic governing equations for elastic wave propagation in an anisotropic medium can be derived directly from the equations of motion for a continuum (in the absence of body forces) (1.1) Assuming a linearly elastic constitutive equation for the material (1.2) we have (1.3) Substituting the strain-displacement relationship (for small displacements) (1.4) into Equation (1.3), we have (1.5) However, the symmetry of the strain and stress tensors requires (1.6) Working with the second term in Equation (1.5), we may interchange l and k (1.7) as (from the summation convention) l and k are dummy indices.