Offre de thèse ZONAL HEALTH MONITORING USING ACOUSTIC & VIBRATORY ANALYSIS

1. CONTEXT In the airlines business, aircraft availability and maintenance costs are very important factors to develop profits. In order to improve them it is necessary to be able to anticipate on up-coming failures. It is also necessary to quickly understand the root cause of a system or structure degradation. This is the objectives of “Health Monitoring”: to be able to know the current health status of an aircraft; to accurately and quickly diagnose the source of a degradation; and to predict an up-coming failure.

Health Monitoring can be valuable to detect technical issues. The difficulty with this solution is that a technical issue is rarely known in advance. So defining which components to monitor, which data to collect, can be quite challenging. Moreover, it is not acceptable to install a large number of sensors. This is why the development of a technology able to detect in a given zone a wide range of degradation can be quite valuable. 2. OBJECTIVES The aim of this Ph.D is to elaborate a solution based on a minimal number of sensors to monitor a wide range of degradation in a given aircraft zone. The degradation to detect can be associated to structures or systems (i.e. the zone to monitor is assumed to have systems components and structural elements). The techniques to consider are based on acoustic analysis and vibratory analysis. The acoustic analysis appears better suited to detect degradation on systems (valve leak, joint degradation, etc), where the vibratory analysis appears more appropriate for structural degradations (cracks, etc). Both techniques should be studied during this Ph.D. The detection of degradation will be based on learning from acoustic/vibratory analysis and will not be based on model development. The reason is that it is almost impossible to model any kind of degradation in a given zone. Several sensors such as microphones can be specifically installed in the zone to detect degradations. Nevertheless it is required to limit the number of sensors installed to minimize complexity (with associated costs and reliability issues) and impact on weight. The primary objective for this Ph.D is to detect an un-anticipated degradation in a given zone. In a second step it will be good to be able to identify & locate the degradation. The ultimate objective is to be able to predict when this degradation will lead to a failure. This Ph.D shall focus on the Powerplant systems. It comprises the pylon, the nacelle, the engine and all the systems around the engine (hydraulic pump, bleed valves, electric generators, etc). So the zone to monitor will probably be one of the Powerplant system zone, more likely the pylon or nacelle zones. These zones are severe environments in terms of noise and vibrations.

Flight tests could be scheduled in the frame of this Ph.D to record representative noise and vibrations in a Powerplant zone. Failure insertion will have to be carefully studied. Lieu: Laboratoire Vibrations Acoustique Campus LyonTech la Doua - INSA de Lyon Bâtiment St. Exupéry 25 bis av. Jean Capelle, 69621 Villeurbanne cedex – France http://lva.insa-lyon.fr/ Profil du candidat : Compétences requises en acoustique et en vibrations ainsi qu’en traitement du signal. Le candidat sera soit issu d’une formation en mécanique soit en électronique. Type de financement : privé Date de démarrage : Septembre 2015 Contact : Jérôme Antoni [email protected]