A multi-channel system for on-line structural health monitoring using guided waves

Reliable and autonomous monitoring systems have been increasingly considered to enhance composite based aerostructures. Unforeseen events like low velocity impacts induce barely visible damage affecting the structure capability to withstand expected loads. Using several transducers capable to excite and detect guided waves, it is possible to efficiently interrogate the structure and detect, locate and characterize typical damage scenarios. However, the on-line detection of small emerging flaws requires instruments enabling measurements on multiple channels with extremely high electronic capabilities. Such devices are requested to simultaneously sort sensors for pitch-catch analysis with one interrogating transducer. Furthermore an integrated software is necessary to elaborate data and provide the diagnosis. This article introduces the design of a compact solution together with an active approach for structural inspection. The detailed description of the device functionality as well as the description of the localization system are discussed. Finally, the evaluation of the overall system capabilities is investigated on a carbon fiber reinforced plastic (CFRP) plate which is designed for a real scale aircraft wing demonstrator. The results summarize the efficient solution in terms of feasible device and reliable localization approach.