Grey relation analysis on fuzzy fault tree of disk brake

The fault states are fuzzy and the relationship between the primary and the secondary factor leading to the fault is uncertain in the course of the reliability analysis of disk brake. To solve these problems, the fuzzy grey relation analysis is used to improve the traditional method, Fault Tree Analysis (FTA). The triangle fuzzy number is used to represent the fuzzy probability of basic event. The fuzzy importance of basic event is calculated by adopting barycenter algorithm. The grey relation degrees between the top event and minimal cut sets are computed after getting incidence coefficients between them. This method is adopted to analyze the fault, inadequate braking moment, of hydraulic disk brake. The order of possibilities that the fault modes represented by minimal cut sets lead to the top event occurrence is determined by comparing grey relation degrees. The results can provide theoretical bases for finding out weaknesses, preventing faults, improving reliability and safety of the system.