Hussein Rappel - Graduate student, Advanced Dynamic and Control Systems Laboratory (ADCSL), School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran
Aghil Yousefi-Koma - Professor, Advanced Dynamic and Control Systems Laboratory (ADCSL), School of Mechanical Engineering, College of Engineering, University of Tehran, Tehran, Iran

Fundamental asymmetric lamb wave’s interactions with rectangular notches in a steel plate are investigated in this paper. Elastodynamic finite integration technique previously mainly used to study wave propagation in elastic media is adopted to study lamb wave interaction with defects. Simulation examples are presented to illustrate the reflection and transmission coefficients’ variations with defect’s height, for both symmetric and asymmetric modes. Results show as the depth of notch increases reflection coefficients for both symmetric mode and asymmetric mode increase. However, when the depth of notch increases transmission coefficient for asymmetric mode decreases which means the main part of transmitted energy is carried by symmetric mode generated when the fundamental asymmetric mode interacts with defect. This simulation could be avaluable tool for the research of lamb wave’s applications in nondestructive testing (NDT) field, as the problem of lamb wave interaction with discontinuities can be used to study defect sizing problem.

EFIT, Lamb waves, Wave scattering, Defect sizing