Study on single mode Lamb wave interaction with defect of plate by finite element model

A finite element model was built for predicting the Lamb wave signals in isotropic material with defect. By acting optimized exciting condition, single mode Lamb wave was generated in the plate with defect. S0 mode and A0 mode are the main modes researched in this paper. A 2-D finite element model was built to analyze the reflection from the defect using S0 mode Lamb wave scattering approach. Complex wavelet transform was applied to extract envelope and arrival time of reflections from defect to evaluate the depth of defect. The predicted signals from finite element model were validated by experimental measurements. In comparison with the results between theory and experiment, it's concluded that the finite element model is effective for predicting the lamb wave signal on UNDE.