Theoretical and Experimental Study of Diffraction of ElasticWaves in Thick Plates

本文对平板中二维和三维裂纹对兰姆波的绕射进行了理论和实验相结合的研究。这些结果将为发展评估固体内部损伤和裂纹的技术提供依据。理论研究将采用有限元与模态展开法相结合的方法。均质板和焊接板中的裂纹都将被考虑。一种新开发的电容式传感器将用于测量板中的垂直表面位移。将测得的位移与理论预测值进行比较。这项研究的目的是分析散射信号与裂缝的尺寸、倾角和埋藏深度的相关性。详细的分析将用于确定裂纹大小和位置的特征特征。

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.