Abstract
In this study, usefulness of lamb waves generated by chirp signals for NDI was examined. The target for the inspection is wall parts of composite propellant tanks. We first studied characteristics of lamb waves propagated around delamination zone by computer simulation. Then, the damage inspection using lamb waves generated by chirp signals was conducted on the composite plates with artificial damaged zone. When the sensor is on the damaged zone, maximum amplitude became 17% of those at sound zone. On the other hand, when the damage zone was between two sensors, scattered lamb waves were monitored. Finally damage inspection system was developed by utilizing these characteristics of lamb waves.
