FEM simulation for Lamb wave evaluate the defects of plates

The experimental method is hard to predict and explain the received Lamb signal of plates due to its dispersive nature. The method to evaluate the depth and defects in plates is investigated theoretically using the finite element method(FEM) in this paper. At first, the theories of Lamb waves in a plate was introduced. Then, the commercial FEM software, ABAQUS EXPLICIT, model lamb wave in plates. The monitor points of healthy plate and defective plate were predicted. The result shows that FEM simulation can effective evaluate the notch by delay time between reflection signal and first echo signal.