Reliability Based On The Product Performance Degradation Data Analysis And Application Of Research

The reliability analysis based on the performance degradation data is an effective approach to evaluating the reliability of long-life products. The main purpose of this thesis is to develop a general-purpose reliability prediction model and the calculation program based on the degradation data of the test samples, the reliability model and revelant program can be used to evaluate the reliability of the long-life product, such as the aircraft hydraulic pump, when lacking of failure data. For this purpose, this thesis discusses the detailed research from three aspects, i.e., theory, programming, and case study (the aircraft hydraulic pump), and the main research contents are as follows:(1) Aiming at the degradation case of single parameter, it studies two basic methods of processing the degradation data, i.e., degradation path fitting method and degradation values distribution method. Based on the previous theory, the TOPSIS method for choosing degradation models is introduced, which solves the problem of reliability analysis when the degradation model is uncertain.(2) Aiming at the accelerated degradation case of single parameter, it studies two basic methods, i.e., accelerated degradation path fitting method and accelerated degradation values distribution method, Based on the previous theory, the accelerated degradation models of single-stress and multi-stress is considered, and the detailed method and steps of the accelerated degradation analysis are developed.(3) Aiming at the degradation case of multiple parameters, it combines degradation path fitting method with reliability calculation method of multiple measures, and develops the reliability evaluation procedures based on the multivariate degradation data. At the same time, the reliability model when the degradation measures are dependent or independent is discussed. As an example, the degradation data of two parameters is simulated, in order to analyze the connection between the reliability and the correlation degree of different degradation measures.(4) Based on all the research work above, it makes a detailed design of the reliability analysis program, and develops the relevant Matlab numerical program, which has certain commonality for the reliability analysis of general products.(5) The application research focuses on an aircraft variable plunger-type hydraulic pump. In order to predict the mean life and reliability of the hydraulic pump, the degradation test data from some aircraft hydraulic pumps is analyzed by the reliability model and the developed programs. At the same time, the prediction results and the precision problems are discussed.At last, the total research content of the entire dissertation is summarized, and the further research work is also prospected.The research work of this thesis has enriched the current reliability theories about degradation analysis. The developed numerical program has certain commonality for the reliability analysis of general products, and can be used to evaluate the reliability of various long-life and test-costly products.