Study On Reliability Assessment Method For Liquid Rocket Engine In The Case Of Zero-failure Data

Reliability assessment method in the case of zero-failure and few-failure data of liquid rocket engine is mainly researched in this dissertation, and it has carried on the discussion to the method that the reliability data conversion under different operating status.First of all, least square method and modified maximum likelihood estimation of zero-failure data for the exponential distribution, the Weibull distribution, the normal distribution and the logarithm normal distribution are given, among them, the Bayes method in the estimation to the failure probability is introduced.Secondly, the situation of few-failure phenomenon may happen in taking a trial run course, so the research of the method to deal with the few-failure data is carried on. And the Bayes method is combined with least square method to provide the reliability estimate including one-failure data.Moreover, the data processing method of accelerated life test is used to solve the problem of the reliability data conversion under different operating status to liquid rocket engine. And the counter power law model is introduced as the relation model between the characteristic life and the combustion chamber pressure, the accelerated life equation of the constant stress accelerated life test for the Weibull distribution is obtained, through the accelerated life equation, the reliability estimate of different combustion chamber pressure is calculated.