Research on probabilistic risk assessment of aeroengine rotor failure

Abstract

The failure of aeroengine rotor will cause a great threat to the flight safety. A new risk assessment model to assess the possibility and severity of failure of aeroengine rotor is presented addressing the problems that its failure samples are not sufficient and that early potential failures are not easy to recognize. The key point of this model is to determine the risk mechanism with diverse failures, failure phase, failure process, historical failure time, and check interval. The risk mechanism is to determine the failure is in the state of relevant failure or not. The failure phases are divided from initial operational state to potential failure and eventually developed to functional failure. The failure process is to confirm possible cascading failure of parts at the same level or of systems. Historical failure time is useful to describe the tendency of failure in the future by Weibull distribution, which is very suitable to depict the rule of mechanical parts failure. Considering check intervals makes the model more complete. These factors to be considered in risk modeling are complete. The relationship has been simulated between failure process and check interval of engine rotor. The risk assessment flowchart of engine rotor has been established after determining failure correlation including nonrelevant failure and relevant failure to another part. The primary failure probability has been predicted through Monte Carlo simulation. In the case of aircraft bursting into flames due to fuel tank breakdown resulted from turbine disk debris, the probability and process model of relevant turbine debris failure have been established through the cartridge receiver, airfoil, fuel tank in sequence. The relevant failure risk of engine part has been evaluated to ensure the safe operation of aeroengine. The aeroengine rotor failure risk model will have great significance in eliminating potential failure and reducing sudden failure.