Monitoring the Damaging Effects of Aircraft Rare Events

摘要

There is a growing interest in developing affordable structural prognostic management systems that can track how each individual aircraft is used and at the same time quantify the damaging effects of usage events. Whilst recorded aircraft flight parameters can indicate the stresses induced by complex manoeuvres, they cannot monitor damaging effects of rare events such as buffeting, hard landing and severe turbulence. Buffeting is an aeroelastic phenomenon, which occurs, in some circumstances, under manoeuvring conditions that involve high angle of attack and can often consume the fatigue life of military fins. Flight parameters such as angle of attack, velocities and accelerations can only determine the likely situations during which buffeting may occur. Other external factors such as air turbulence, wind speed, wind direction and gusts can have an influence on the phenomenon and, hence, for the same set of measured flight parameters, buffeting may or may not take place depending on these external factors. Hard landings can also consume the fatigue life of undercarriage attachments. Smiths Aerospace has developed mathematical networks that combine mathematical models, artificial intelligence and engineering knowledge to synthesise stresses from flight parameters. Working with BAE SYSTEMS, a mathematical network was configured to monitor the damaging effects of rare events. The configuration of the mathematical network involved modal analysis and a simplified Eurofighter finite element model. The paper describes the artificial intelligence, model-based approach to rare event monitoring and reports its preliminary results.