UCLA

Ultrasonic guided waves offer an attractive cost effective tool for inspecting large structures. This is due to the fact that guided waves can propagate a large distance in plate like structural components and are strongly affected by the presence of defects in their propagation path. Propagation characteristics of Lamb waves have been studied extensively over many years, where the waves have been studied at a large distance away from the source, independent of the source influence. The literature on propagation of Lamb waves including the influence of the particular source responsible for the wave motion in the plate is comparatively much more sparse. In this dissertation the propagation of waves in a plate due to different kinds of applied loads is studied. Two dimensional and axisymmetric models are analyzed and the waves are studied both near the source and far away from it. The energy carried by the waves and how they vary depending on the type of applied load are studied. This provides the knowledge base to characterize and ultimately minimize the energy loss in various engineered structures and devices, including in the design of resonators by minimizing the ``anchor loss" associated with them.