Fault tree analysis of complex multistate system with fault statistically dependent components

To exactly estimate the reliability of reusable rocket engine, a Boolean algebra with restriction on variables was introduced to properly combine fault tree analysis with state analysis, and the reliability analysis of complex multistate system with statistically depent components were performed. Both the multistate of pipes and the statistical dependence between preburner and turbopump of space shuttle main engine (SSME) were deeply studied. The result show that the Boolean algebra can well eliminate statistical dependence among components to simplify the fault tree analysis of complex multistate system, and the statistical dependence has significant influence on the system reliability, so further research is required for higher performance of the reusable rocket engine.