Lamb wave interaction with structural defects - Modelling and simulations

Lamb waves have shown to have a great potential for Structural Health Monitoring. The method uses acousto-ultrasonic waves propagating in plate-like structures. Structural damage can be identified by an amplitude change and/or mode conversion. However, previous studies show that the voltage amplitude from low-profile piezoceramic sensors can change due to temperature effects or additional vibration excitation. Also, pure Lamb wave modes may generate a variety of other modes by interacting with defects and/or by crossing different boundaries. Therefore simulation studies of wave propagation in structures is important for damage detection analysis. An application of the Local Interaction Simulation Approach (LISA) for Lamb wave interaction with defects is presented in this paper. The simulation results are validated using the experimental analysis. The method shows the potential for complex modelling of acousto-ultrasonic waves in damage detection applications.