DLR Research Activities for Structural Health Monitoring in Aerospace Structures

The paper describes the diverse research activities of the DLR in the topic of Structural Health Monitoring (SHM). SHM based on Lamb waves is a promising method for in-service inspection of aerospace structures without time consuming scanning like conventional ultrasonic techniques. Lamb waves propagate over large distances and can be easily excited and received by a network of piezoceramic actuators and sensors. Lamb waves are able to interact with structural damages due to their high sensitivity to discontinuities in materials. In principle different kinds of structural defects can be detected and located by analyzing the sensor signals. The activities at DLR are focussed on the visualisation of Lamb wave propagation fields based on air-coupled ultrasonic technique, the simulation of virtual sensors, mode selective actuators as well as manufacturing of actuator and sensor networks