An improved method for ray tracing through curved inhomogeneities in composite materials

Ultrasonic NDE of anisotropic materials, due to its inherent complexity, demands a stringent approach to determine wave propagation path in presence of inhomogeneities. In addition to developing inspection procedures, the ray path information needs to be integrated with the tomographic reconstruction algorithm of composite materials. The present study proposes a method to identify inhomogeneity boundaries using edge detection approach and to implement the same in two-dimensional ray tracing model. In general, inhomogeneity boundaries can be detected on the basis of first-order gradient of a field value (such as Young's modulus). The boundaries can be represented in terms of location and orientation. This information is included in the algorithm for more accurate ray tracing. Examples show the usefulness of the method to take into effect poor penetration of ultrasound energy in certain regions of inhomogeneous materials.