Research On Methods Of The Reliability Assessment With Small Sample For Complex System

With the development of national defence science and technology industry, for highly complex defense weapon equipment system, precise reliability assessment is required to control the reliability level scientifically. So for test information in system level with the aspect of small sample,reliability assessment based on classical statistical analysis becomes difficult. This thesis studied and solved the reliability assessment using classic method, Bayes method and information fusion method for complex system with the aspect of small sample from the perspective of system engineering and information theory.Based on the basic theory of system reliability assessment, the classical and Bayes reliability assessment method for the binomial, exponential models, and the least square method and maximum likelihood parameter method for Weibull model are discussed and summarized. With the in-deep analyzing of classical assessment methods such as MML, LM,SR,and CMSR, engineering formulas for series system, parallel system and k-out-of-n system consist of the same or different life distribution unit are derived, and the general mixed system classical comprehensive assessment theory is presented. For unit or system with a-priori information, reliability assessment is conducted for typical simple system and typical complex system using Bayes synthesis method and Monte Carlo simulation method. The numerical examples carried out show the accuracy of the methods. In order to solve the inaccurate caused by singularity of information sources of classical method and Bayes method,the information fusion method of expert experience information, components and subsystems information,and reliability growth information are discussed,the inheritance and diverse population of information sourceare considered, the information fusion reliability assessment method containing inheritance factor is introduced. The result of reliability analysis model for solid rocket motor with small sample indicates the rationality and the application prospect of information fusion method.In a word, a set of system assessment methods with complex constructions and various life distributions is studied, which are basically suitable for practical engineering. Therefore this research is valuable for highly complex defense weaponry system.