Research On Maintenance Strategy For Gantry Crane Based On RCM

With the rapid development of the national economy,cranes play an important role in realizing the mechanization and automation of production process,it also improves the handling conditions and the production efficiency.At the same time,crane accidents caused by unreasonable operation and maintenance work are increasing year by year,resulting in a lot of property damage and personal injury.In view of the high maintenance cost and low maintenance efficiency of gantry cranes,how to determine the best maintenance strategy for crane equipment to achieve economical and reliable maintenance has become the focus of modern equipment maintenance.Through the analysis and comparison of the development process of China's gantry crane maintenance system and foreign equipment maintenance system,the reliability-centered maintenance theory is adopted to study the gantry crane equipment maintenance strategy in this paper.The main contents include the following aspects:Against the problem of insufficient maintenance or over-maintenance during the maintenance process of traditional cranes,the method of formulating maintenance strategies for gantry cranes based on RCM is studied.Hazard matrix analysis method is used to determine the important functional equipment of the crane,and then FMECA and FTA are combined to analyze the impacts and criticality of failure modes for important functional equipment of the crane lifting mechanism.The FMECA table of the crane lifting mechanism is established to provide supports for formulating gantry cranes' maintenance strategies.The maintenance type of the equipment need to be determined and also the corresponding maintenance cycle need to be given to formulate the RCM maintenance program of gantry cranes.First,the influence factors of maintenance mode evaluation are comprehensively considered,starting from reliability,economy and maintainability,and the decision-making evaluation system for maintenance methods of gantry crane equipment is established.Aiming at the complex structure and the subjectiveness and fuzziness of the selection of maintenance methods for cranes,a maintenance method decision method based on combination weighting and grey correlation analysis is proposed.The subjective weights determined by the analytic hierarchy process method and the objective weights determined by the entropy weight method are used to get the combined weights of each evaluation index.The fuzzy judgment method is used to establish the maintenance decision evaluation model based on the grey correlation analysis and the effectiveness of the evaluation method is verified.Secondly,the model of preventive maintenance cycle is studied.Based on the principle of maximum availability and minimum maintenance cost,the preventive maintenance cycle model is established.Considering the principle of availability and economy comprehensively,the model of preventive maintenance cycle is further optimized according to the absolute comparison method of fuzzy decision,and an example analysis is conducted to verify the feasibility of this model.The gantry crane maintenance decision system based on RCM is developed.Through analyzing the business requirements of the system,the system database is built,and the information management module,equipment importance module,FMECA module,maintenance decision module,maintenance cycle module and maintenance record module are implemented.The system realizes the information management of gantry cranes' equipment.In addition,according to the data of importance information for equipment,failure mode impact and hazard analysis,equipment maintenance records,the best maintenance methods and maintenance cycle of crane equipment can be determined to provide guidance of developing maintenance strategies reasonably for maintenance personnel.