Hardware proposal for SHM in airborne vehicles

Abstract

Nowadays, not only must the structures be in good health when they are manufactured and installed, but also their integrity must be monitored during their life cycle. Nondestructive Test (NDT) techniques are applied in the beginning of the cycle, and Structural Health Monitoring (SHM) techniques afterwards. There is a wide literature on how to monitor integrity in large civil structures, where the size of equipment and accessibility for testing are not serious problems. There are studies that deal about the integrity of airborne vehicles, some focused on the inspection technology or the algorithms used. However, the integrity inspection of an aircraft also requires the development of reliable low volume lightweight electronic equipment with high technical capability. The authors are developing electronic prototypes to satisfy such requirements. The goal of this research is to build an on-board electronic system that monitors the integrity of the airborne structures throughout its lifetime. The prototype uses ultrasound technology with piezoelectric transducers (PZT) and can emit and acquire waveforms on multiple channels simultaneously (pulse-echo or pitchcatch schedules). It can use many test techniques: simple test, beamforming transmission, fast round-robin (associated with beamforming reception), multiple delayed signal, etc. The prototype can generate steerable beams as required. It can also operate in passive mode, i.e. listening to acoustic emissions. The prototype weights 600 g, includes USB 2.0 connectivity, and compresses the data before uploading them to a computer.