This research performs a combined theoretical and experimental study of diffraction of Lamb waves by two- and three-dimensional cracks in a plate. The results will provide the basis to develop techniques for assessing the internal damage and cracks in solids. The theoretical study will use a hybrid finite element and modal expansion method. Cracks in a homogeneous as well as in a welded plate will be considered. A newly developed capacitive transducer will be used to measure vertical surface displacements in a plate. The measured displacements will be compared with the theoretical predictions. The goal of this investigation is to analyze the dependence of the scattered signals on the dimension, angle of inclination, and depth of burial of the crack. The detailed analysis will be used to identify characteristic features for crack sizing and location.
