Research On Safety Service Life Prediction Method Of Remanufactured Impeller With Fuzziness Of Fatigue Damage And Its Application Of Support System

The remanufacturing of mechanical equipment is a sustainable manufacturing mode taking damaged or decommissioned parts as remanufacturing blanks,using remanufacturing techniques and realizing “turning an old part into a new one” so as to prolong the service life of products,reduce resource cost and environmental pollution and increase resource utilization rate.Using technical innovation to fully tap the surplus value of retired products is the essence of remanufacture,which can further speed up the construction progress of a resource-saving and environment-friendly society.China has become a global mechanical equipment manufacturing power and an increasing number of mechanical equipment have been or are going to be retired.Therefore,studying the basic of remanufacturing science helps to improve the equipment remanufacturing level and ensure the smooth development of remanufacturing industrialization in China.The core challenge of remanufacturing is how to improve the safety and prolong the service life of remanufactured products.Besides,the estimation of safety and service life of remanufacturing product,one of key technologies in remanufacturing,is in urgent need of theoretical support as it involves many subjects and fields.Supported by the National Basic Research Program of China,named “Life Prediction of Remanufacturing Parts and Service Safety Verification of Remanufacturing Products”(No.2011CB013405),the Specialized Research Fund for the Doctoral Program of Higher Education of China,named “Study of Evolution Mechanism and Prediction Method of Remanufacturing Mechanical Parts”(20110191110005),and other programs,this paper focused on the study of the remanufacturing impeller of centrifugal compressor,including the research of the safety service life amount prediction and supporting system of centrifugal compressor remanufacturing impeller by taking the damage fuzziness into consideration,to provide the safety service life of remanufacture parts with theoretical support.Firstly,as for the problem of fuzziness characters existing in calculating the fatigue damage,the modification model of Miner criterion based on fuzzy theory was created.Factors affecting remanufacturing impeller fatigue damage like blank quality were deeply analyzed;the evaluation standards for fatigue damage amount were constructed;the evaluation model of remanufacturing impeller fatigue damage was built based on Fuzzy Comprehensive Evaluation(FCE).The fatigue damage modification model based on fuzzy theory was built after considering the fuzziness in remanufacturing impeller life prediction to provide scientific basis for service life prediction.Secondly,based on remanufacturing impeller safety service feature,remanufacturing impeller safety evaluation and fatigue damage fuzziness and service load features,the safety service life prediction model centering on the remanufacturing impeller safety evaluation,modification model considering fatigue damage fuzziness,safety service load coupling model and material fatigue limit modification model to provide a theoretical reference for the safety service life prediction.Thirdly,3D modeling theory and finite element modeling technique were adopted to solve the property problem of “blind piece” and build the remanufacturing impeller geometric model and all-hexahedral FEM mesh model,which can reflect failure features;on this basis,use experiments and numerical simulation technique to analyze the residual stress load of remanufacturing impeller laser cladding;the coupling model of centrifugal stress load and pneumatic stress load was built;modes rule in wake excitation produced by impeller was also analyzed.The above research models offers scientific support to safety service load spectrum.Furthermore,the modification model of FV520 B material fatigue limit was established by building impeller material fatigue life model in asymmetric stress state;by analyzing remanufacturing impeller service working condition characters,based on load rain-flow counting theory,the load spectrum was analyzed.The safety service life of remanufacturing impeller was predicted by conduct fatigue damage fuzziness analysis and applying Fe-safe software.Besides,relative fatigue lives of remanufacturing impeller in different residual stress,rotation speed and other special working conditions were discussed.Finally,a support system designed to predict the safety service life of remanufacturing impeller of large centrifugal compressor was developed by taking finite element analysis software – ANSYS as a platform and using Visual Basic(VB)and SQL server 2005,which can be used to conduct numeric analysis of remanufacturing impeller safety service life.