Simulation of Lamb Wave Modes Conversions in a Thin Plate for Damage Detection

In this paper, the propagation of Lamb wave in a thin metal plate is carried out using finite element method. Where it is crucial to acquire information about Lamb wave propagation, its dispersion behaviour, its feature when it scattered from faults. A pitch-catch method is adopted to model the measurement system where two PZT wafers are mounted on upper and lower surface of the plate to act as actuators to transmit the desired Lamb wave mode (S 0 or A 0 ), and the single PZT wafer placed at a specific distance from actuator acting as a sensor. The interaction between Lamb waves with a notch perpendicular to the upper surface of the plate for different Lamb wave modes is simulated to interrogate the effect of presence notch on Lamb wave propagation. Finally, the mode conversion between S 0 and A 0 mode occurs due to presence damage which leading to new wave packet in time domain response of Lamb wave propagation.