Research On Reliability Evaluation Technologies For Cycle-Bump On Temperature-Control System Of Space Shuttle

Space shuttle is equiped with temperature-control system to keep feasible temperature for cosmonauts and equipments. Liquid-cycle-cooling system is the important part of temperature-control system, it uses cycle-bump to impel liquid cycling to control temperature. So cycle-bump becomes the key equipment to ensure liquid-cycle-cooling system running normally. The reliability of cycle-bump directly influences the reliability of liquid-cycle-cooling system and Space shuttle. The thesis's mission is to find advanced reliability evaluation method and evaluates the reliability of cycle-bump well and truly with cycle-bump's information and test data.At First, according as the theory and test instance of cycle-bump, the thesis makes FMEA analysis and indicates the key performance indicators of cycle-bump.Then the thesis evaluates the reliability of cycle-bump base on life data. The thesis studys the equivalent exponential distribution best lower confidence limit estimation method and Bayes-Weibull model method. The result shows that the equivalent exponential distribution best lower confidence limit estimation method is poor in the small sample and short test time circumstance with no fault. Correspondingly, the Bayes-Weibull model method uses some prior information and achieves reasonable result.Considering it has recorded much performance data of cycle-bump in test, the thesis researches the performance reliability evaluation method. The thesis expatiates the concepts of performance degradation and performance reliability; constitutes a two-point normal distribution model and a stochastic model to describe performance reliability. Two models achieve better results. The reasonable results show that in the small sample and short test time circumstance with no fault, two models can make the most of life time information and performance information of sample. They are excellent models.At last the thesis compares with the reliability evaluation methods above and gives the appraisement. It educes the conclusion that the reliability of cycle-bump has achieved the request.