Ultrasonic Wave Propagation through Solid Media

Abstract

Structural health monitoring is an emerging technology which is used broadly to identify, locate, and quantify structural flaws or damages before failure. Ultrasonic guided waves are used to detect the defects in the structures in dry conditions or immersed in liquid without causing any effect to it. Lamb waves are widely used as they can travel large areas. With the development of various simulation techniques, it is interesting to see whether wave modeled in these simulation tools can exhibit integral characteristics of the lamb wave. The objective of this research is to determine the responses of Lamb wave generated using finite-element software package ANSYS and asses its propagation in an isotropic healthy plate. Further the FE model is used to investigate the interaction of Lamb waves when the subject plate is subjected to different environment i.e. plate in air, plate immersed in liquid. Artificial defects like notches are generated to check the fidelity of the model in detecting flaws. Propagation characteristics of different Lamb wave modes are studied in the plate specimen and experimental results are also generated to validate the model.