Reliability Modeling And Assessment Of Complex System Considering Multiple Failure Modes

With the increasing complexity of modern equipment systems,the traditional system reliability modeling and evaluating theory is difficult to be applied to the complex system,which has the complex characteristics of Multiple-Failure Modes,Multi-State and Multi-Stage.In this paper,based on the unit reliability model with Multiple-Failure Modes,a set of reliability modeling and evaluating methods for complex systems are proposed considering the above complex characteristics.The main contents of this paper are as follows:(1)Reliability modeling and evaluation of Multi-State System(MSS).The specific assumptions,classification,correlation processing rules of multi-failure modes reliability model,and reliability model of single fault mode has been put forward.Based on the failure modes described by the stochastic process model and the life distribution model,the typical reliability model and the general model of Multiple-Failure Modes unit are established.A reliability evaluation method based on the unit reliability model with MultipleFailure Modes and Multi-state Multi-valued Decision Diagram(MMDD)is proposed to solve the reliability evaluation problem of MSS.A satellite momentum wheel was taken as a case study to introduce the reliability modeling and evaluation process of MMS with MultipleFailure Modes.(2)Reliability modeling and evaluation of Load Sharing Voting System(LSVS).The voting system with load sharing effect in this paper was consider to be a special multistate and multi-stage system.A system reliability model based on Accelerated Failure Model,Cumulative Damage Model and Event Space Method has been proposed for reliability evaluation of LSVS.Based on the above model,a system reliability model with three systemlevel failure modes has been proposed for LSVS with Multiple-Failure Modes.A satellite battery group was taken as a case study to introduce the reliability modeling and evaluation process of LSVS with Multiple-Failure Modes.(3)Reliability modeling and evaluation of Multi-State Phased-Mission System(MS-PMS).The MS-PMS is a kind of common multi-state and multi-stage system.The correlation processing rules between different stages has been proposed,respectively for the typical reliability model and the general reliability model of the Multiple-Failure Modes unit.A hierarchical analysis,modeling and evaluation method based on PMS-MMDD and MultipleFailure Modes unit reliability model has been proposed for MS-PMS.The Attitude and Orbit Control System of a satellite was taken as a case study to introduce the reliability modeling and evaluation process of complex system with the characteristics of Multiple-Failure Modes,Multi-State and Multi-Stage.The validity of the model and method in this paper has been verified by the calculation results of the above cases.