Abstract: DUGAN dynamic fault tree is composed of static subtree and dynamic subtree. The static subtree is traditional fault tree, which uses traditional logic gates such as AND, OR gate and so on to describe static failure behaviors. The dynamic subtree uses dynamic logic gates such as the priority AND gate, the functional dependency gate, the sequence enforcing gate, the spare gate and so on to describe dynamic failure behaviors. Compared with traditional fault tree, T-S fault tree can describe any combinational and multi-state static failure behaviors, but it still can not describe the system consisting of dynamic failure behaviors. To improve the ability to describe combination of any static and dynamic failure behaviors, T-S dynamic fault tree analysis method is proposed. First, T-S dynamic gate that describes static and dynamic logic relationship is defined and construction method of T-S dynamic gate rule including time state rule and event occurrence rule is proposed and T-S dynamic fault tree analysis and calculation method based on T-S dynamic gate input and output rules algorithm is proposed. T-S dynamic gate rule can infinitely approximate the failure behaviors of the real system. It can not only describe the dynamic failure behaviors described by DUGAN dynamic gates, but also describe the static and dynamic failure behaviors that DUGAN dynamic gates cannot describe. Finally the feasibility and calculation simplicity of the proposed method are verified by comparing with discrete-time Bayesian networks, Markov chains and sequential binary decision diagrams solving DUGAN dynamic fault tree.

Key words: dynamic fault tree, fault tree, T-S dynamic fault tree, T-S dynamic gate, T-S dynamic gate rule