Reliability analysis and design for the aerospace valve

The valve is a very important part in the astronautic systems. The paper presents the reliability analysis ideas and technological process for the aerospace valve during the valves design phase. The method is based on the qualitative analysis method (Failure Modes Effect and Critical Analysis, FMECA) and the quantitative analysis method (Stress Strength interference theory), including the weakness components reliability analysis and the valves system performance reliability analysis. Firstly, the main failure modes and weaknesses of the aerospace valves are obtained by using FMECA and investigation of similar valves' testing data. Secondly, based on the analysis of influencing factors and its randomness, combining the failure physics model with stress strength interference theory, the reliability models for the weaknesses and main failures can be acquired and the reliability index can be calculated. Thirdly, considering that the valves are self-feedback control systems, the reliability of the performance of the valve should be paid attention to. So based on the simulation model for the operation characteristics of the whole valves established by AMESim software, the performance reliability of the valves is analyzed in the paper. Lastly, an aerospace valve reliability analysis example is given, and the result indicates that the proposed method is reasonable and helpful.