Circular 02/03 : data collection : collection arrangements on learner data

"This circular is for consultation. It sets out the medium-term strategy of the Learning and Skills Council (the Council) for collecting data on learners and provides details of the proposed content of the Individualised Learner Record for further education institutions and work based learning providers for 2002/03" -- front cover

Sensor validation of a Structural Health Monitoring Process for Aircraft Nacelle

This paper details the implementation process of an embedded structural health monitoring (SHM) system enabling condition-based maintenance of aircraft nacelles. One critical issue before being able to make use of such system is to ensure the effective bonding of the chosen actuators and sensors with their host structure, especially as the latter will be exposed to harsh environments and wide operational variability. In this work, we are concerned with the composite components of the nacelle and we use piezoelectric elements as both sensors and actuators. We propose an integrated approach that allows to validate a combination “Substrate—Glue—Piezoelectric” (SGP) and thus provides criteria to choose and size these assemblies. This validation scheme is based on the observation of the variations of the static capacity of the piezoelectric element after enduring various temperature and stress conditions when bonded to its host structure. Based on those SGP combinations, an active SHM strategy interrogating the structure by means of elastic wave propagation is currently being developed and preliminary results on samples representative of the nacelle are presented and discussed.Projet AIRCELLE (EPICE/CORALIE