The Analysis Of Fuzzy Reliability In Repairable System

Reliability is one of the most important indices to evaluate the quality of product. Since 1950s,the typical theories on the reliability developed quikly for their wide use, and got some wonderful results.During the 1960s,the notion of fuzzy reliability naissaned and quikly growed into fuzzy mathematics.From then on the fuzzy ways guided by fuzzy mathematics were windly used in many domains.With the development of research,people begin to realize that there exist not only randomness but also fhaziness in praetieal problems.so people begin to study fuzzy reliability.Currently,it has become a most popular researeh direction.However,now the research of fuzzy reliability is mainly on the non-repairable system,people rarely study on the repairable system.The theory and method of fuzzy reliability are not perfeet.On the basis of the existing research harvest,this paper has studied the fuzzy reliability of some important repairable systems.①First,this chapter introduces the production and development of fuzzy reliability,significance and present condition of the fuzzy reliability in the repairable systems.Then the author summarizes the concepts of reliability indexes and mathematical theory for repairable systems,and concrete computational approach of fuzzy reliability.②Based on the fuzzy stochastic processes,the fuzzy reliability and fuzzy availability of repairable series connection system are researched on the circumstance of different instruments and same instruments,respectly.③On the basis of the theory of fuzzy reliability and the principles and methods of fuzzy mathematics,the fuzzy reliability indexes of repairable system are expanded.On this basis,for repairable parallel and series connection system,the computational approach of fuzzy availability is proposed.Finally,a real example is given to express this concrete computational approach.④The states of repairable vote systems w ere analyzed by using Markov chains. The probability of states was gotten.Then the failures of repairable vote systems were classified,the membership functions of the states to fuzzy success were defined and the reliability of repairable vote systems was analyzed by using the reliability theory based on fuzzy-state.The difference between fuzzy reliability and tradition reliability was compared.In the end,an example was given. ⑤Based on the reliability theory,fourth chapter gives a comparison on the improvement of reliability made by series connection and by parallel connection on instruction and systems,focus on the system of series-parallel connection and the system of parallel-series connection,I have analyzed the different conditions when we use different instruments and same instruments,and the brief proof are given.⑥Finally,the thesis is summariezd,and the further researeh works about the fuzzy reliability analysis are pointed out.