T-S Dynamic Fault Tree Importance Analysis Method And Its Applications

Fault tree analysis is one of the most widely used methods of system reliability analysis.The static fault tree analysis method can not describe the logic relationship of dynamic in the system.Dugan dynamic fault tree describes the logic relationship of dynamic in the system through dynamic logic gates such as priority-AND gate and spares gate,but it can not describe any form of failure logic relationship of static or dynamic in the system,and can not be directly analyzed quantitatively.It usually needs Markov model,Monte Carlo,Bayesian network and other methods.T-S dynamic fault tree analysis method makes up for the deficiencies of analysis method of static fault tree and Dugan dynamic fault tree,and enhances the ability of fault tree describing static and dynamic failure logic relations.In order to enhance the applicability of analysis method of T-S dynamic fault tree,the multi-state T-S dynamic fault tree analysis method is studied to solve the question of reliability analysis of multi-state systems with dynamic failure behavior.Furthermore,the T-S dynamic fault tree importance measure is proposed.Firstly,the T-S dynamic fault tree analysis method is studied.The T-S dynamic gate of describing static and dynamic logic relations and its description rules are introduced.The calculation method of T-S dynamic fault tree based on input and output rules of T-S dynamic gate is given.The feasibility of T-S dynamic fault tree analysis method is verified by comparing with thediscrete-time Bayesian network solving Dugan dynamic fault tree,and the T-S dynamic fault tree analysis method is applied to reliability analysis of digital electro hydraulic control systemSecondly,in order to solve the problem of reliability analysis of multi-state system with behavior of static and dynamic failure,and the multi-state T-S dynamic fault tree analysis method is studied.The description rules of T-S dynamic gate for multi-state system are constructed and the mission time is discretized.Further,the calculation method of multi-stateT-S dynamic fault tree is given.The feasibility of the proposed method is verified by compared with T-S fault tree analysis method,and the multi-state T-S dynamic fault tree analysis method is applied to reliability analysis of machining center turntable.Then,based on the T-S dynamic fault tree analysis method,the traditional fault tree importance measure analysis method is extended to the T-S dynamic fault tree,and the T-S dynamic fault tree importance measure is proposed,including Fussell-Vesely importance measure,differential importance measure,upgrading function and integrated importance measure,and the calculation method of basic events in each time interval and the mission time is given.The feasibility is verified by comparing with traditional fault tree importance measure analysis method.Finally,the T-S dynamic fault tree importance measure was applied to reliability analysis of the hydraulic brake system of mine hoist,calculating failure probability of system and importance measures of basic events,which provides reference to identify weakness and improves the reliability of the system.