The Life Evaluation RLT-GERT Network Model Of Reliability Test For Complex Equipment Of Small Sample

Reliability test evaluation for complex equipment often faces the difficulties caused by small sample characteristics. This paper discusses the influence of stress impact on equipment reliability and its application of small sample reliability test analysis modeling based on the existing domestic and abroad reliability analysis, evaluation and test methods. A new reliability evaluation model is proposed which combined with the validity of the complex product system structure analysis by the reliability block diagram and the advantage of equipment operation process description by the Graphic Evaluation and Review Technique(GERT). The model provides a perspective of impact stress in reliability test analysis. The main research content in this paper is as follows:(1) A GERT network model based on failure choice mechanism of small sample is proposed through the analysis of the equipment failure mechanism under impact stress and statistical law of failure data. First the GERT network is introduced to describe the random process of equipment state transition after stress impact, then determine the parameters in network according to the experimental data and a few experts prior information, at last, calculate the network parameters by equivalent moment generating function.(2) A virtual-real synthesis equipment reliability test RLT-GERT network is constructed based on the thought of complex equipment parts failure caused by stress impact in operating environment, to realize the conversion of equipment parts test data to system data, providing the reference for complex equipment system reliability assessment. Firstly, the reliability block diagram is used to transfer the complicated equipment into a logical relationship network of the reliability unit, the reliability block diagram is converted to a GERT network, to deduce the equipment running process. Then do the quantitative analysis of characteristics of the equipment life by equivalent moment generating function.(3) A virtual-real synthesis equipment reliability test RLT-GERTS network is designed based on extensive logical node in GERTS and Monte Carlo method. The algorithm of the reliability evaluation model of complex equipment system is given, and the solving process is illustrated by a mission reliability of an unmanned combat aerial vehicles, achieved reliability test data virtual generated. Due to the Monte Carlo method is needs little restrictive conditions, the model is suitable for reliability analysis of complicated situation.