LESSONS LEARNED FROM RECENT EUROPEAN RESEARCH PROJECTS ON AGEING AIRCRAFT

摘要

Prom the structural point of view, the phenomena of Multiple Site Damage (MSD) and Widespread Fatigue Damage (WFD) have been found to be most interesting with regard to the life extension of commercial transport aircraft. These phenomena have been treated both, in the US and in Europe during the last years. Different European research projects on the special problems arising from the use of Ageing Aircraft yielded some interesting results, mainly in the way that a probabilistic approach has been chosen for the assessment of MSD and WFD. This is quite different from the general US approach, which was mainly focused on the residual strength problem for MSD scenarios. The present paper gives a very personal view of the lessons learned from some of the European projects by using results from the in-house model derived during the last years. The model is based on the idea of a Monte-Carlo Simulation for the process of initiation and growth of MSD- scenarios. One of the most essential points found by the use of such a model is the result that MSD is a scenario which is not very likely to be found under circumstances, which are linked to well designed and maintained fuselage and wing structures of civil transport aircraft. Special effects must occur in order to allow the occurrence of MSD. One of these circumstances may be corrosion or debonding in joint areas. The basic model has already been published, but different features have been added recently. One of these is the deteriorating effect of corrosion etc. New results accompanied by some lessons learned in recent years will be presented and a short outlook will be added.