The Research On Preventive Maintenance Decision Of Complex Equipment Based On Reliability Analysis

More and more new subjects about the maintenance decision research come forth because of the complexity of equipment. By improving the decision model and method of maintenance mode, scheduled maintenance cycle and condition based maintenance (CBM) threshold, the goal of this thesis is to solve the maintenance problems of complex equipment.The characters and the categories of maintanence mode of complex equipment have been analyzed firstly. And the criticality evaluation index system has been constructed including reliability, maintainability, inspection and economy factors. Then a bivariate Weibull distribution model, non-fatal shock mixture model, has been established to determine the reliability life distribution of the complex system with dependent components. And a synthetical approach has been suggested to estimate the parameters of the distribution model. Furthermore, a multi-objective maintenance cycle optimization model has been presented to find the sechduled maintenance cycle to achieve the satisfying availability with minimal maintenance cost. The applicability of this model is better than the existing research because the multiformity of the maintence and failure type has been taken into account. Finally, a kind of CBM maintenance threshold decision model has been described which is based on the Weibull proportional hazards models (WPHM). The model may reflect the relation between the operation state and the inspection index according to the exsting inspection data.The functionally significant item (FSI) and the maintenance mode of the railway locomotive engine have been obtained firstly. Then the reliability life distribution of the engine has been determined by employing the Weibull non-fatal shock mixture model. And the feasibility and veracity of the model have been proved by the analysis of the goodness-of-fit. Finally, the scheduled maintenance cycle of the supercharger and transmission of the locomotive have been calculated by multitarget sechduled maintenance cycle optimization model. And the CBM decision policy of the injection pump and water injecting pump by employing the decision model and process presented in this paper. All application study of these two preventive maintenance modes has shown the validity and applicability of the decision mode and method.