A Quantitative Assessment Method for the Failure Severity of Systems in Aero‐Engine Under Fire Environment Considering Prevention and Control Measures

ABSTRACT Fire accident caused by oil leakage on hot surfaces in aero‐engine can lead to the failure of some systems in that area. Previous methods for assessing the failure severity of systems in aero‐engines under fire environment have typically employed qualitative analysis, without considering the mitigating effects of fire prevention and control measures. Therefore, a quantitative assessment model for the failure severity of systems in aero‐engines under fire environment is proposed in this study. In this model, the state transition probabilities of the subsystem under fire environment are obtained using Markov chain based on cumulative temperature and absorbed thermal dose. By incorporating the transition probabilities, a mathematical model of the failure severity for the system is constructed. Furthermore, a quantitative methodology for assessing the mitigation of system failure through the implementation of fireproof materials, extinguishing agents, and drainage measures is established. A case study is used to illustrate the developed methodology. Based on this case study, the effects of important parameters on system failure severity are analyzed, such as reliability structure between subsystems. Additionally, the effectiveness and utility of different fire mitigation strategies are discussed.