What is the principle of damage detection using Lamb waves?
In SHM, PZT actuators are often used to actuate the structure. This will produce Lamb waves propagating in the structure, which can be measured using PZT sensors. The PZT actuators can also be used as sensors. When there is a damage on the structure, the Lamb waves propagating through the damage will change. By measuring the change, we will be able to identify the damage. In SHM, a network of actuators and sensors is often used so that the system can scan and monitor a large area of structure or a hotspot area that is of particular concern.
