Technical research on active detection and monitoring of damage in metallic plate based on lamb wave

A built-in active multiple-actuator structure health monitoring system was developed, and the flow chart and the principle of damage detection using lamb wave was introduced. The frequency dispersion of the testing aluminum plate was measured, and the measurements on some diagnose paths were completed using different PZT as actuators and sensors. The response data of damaged and undamaged were analyzed and compared, the rule of the wave pattern change was found. The damage index was defined as the ratio of scatter energy to baseline energy, the influence of hole on damage index of different diagnose path were given, and the results showed that this feature could be used to identify the location of the damage.