Research Of Joint Failure Importance In Fault Tree Analysis

Fault tree analysis (FTA), an important branch in systems reliability engineering, is widely used in aerospace, nuclear power, electronic, machine, electric force, chemical industry, transportation and even the field of civil construction. For a long time, Fault tree analysis is used for the quantitative and qualitative analysis of critical system's failure modes, provides a mathematical expressions and graphs of event which lead to system failure. Fault tree model can find the potential weak of system, and guides the operation, maintenance and optimization design of system.Importance analysis is an integral part of FTA, it has been well studied and widely used in the actual project. Important analysis is helpful to improve the system reliability effectively, also it is used to provide the most effective design or to find the reasons of system failure. Along with the development of science and technology, the products are increasingly large and complex, Important of individual component unable to provide more and more effective data for the design of systems'or components'reliability. Joint importance of components has become a necessary means for reliability analysis, also it is the research purpose of this thesisThis paper based on details the basic methods and principles of fault tree theory, Studied the method of qualitative and quantitative analysis in two-state fault tree. This paper find out some problems in J.S. Hong importance, after studying the Z.W.Birnbaum importance and J.S. Hong importance, so it is necessity to propose a new algorithm. And the detailed calculation of the improved importances is illustrated with an example of a fault tree. It finally proves that the improved algorithm is reasonable by comparing their result.