Study Of Service Safety Assessment Method For Remanufactured Impeller With Fuzzy Theory

Researches on key scientific issues of remanufacturing and original innovation of remanufacturing core technology are urgent needs of sustainable development in our country and keep in line with major strategic goals. Master life evolution law and ensure service safety of remanufactured product are fundamental criterions of success, but life prediction theory and health monitoring methods based on homogeneous material are not entirely suitable for a multi-component?high-disordered material properties and multi-strong field coupling effect injury remanufactured parts.Influence of fuzzy uncertainties on remanufactured parts service safety and life prediction during service process have become an important research direction of remanufacturing theory.This research work is supported by the Major State Basic Research Development Program of china(973 Program)(No. 2011CB013405), and the Ph.D. Programs Foundation of Ministry of Education of China(No. 20110191110005).Based on fuzzy uncertainties during remanufactured parts service process, remanufactured parts service safety assessment and life prediction methods were studied by fuzzy theory.First, the integrity assessment methods of remanufactured parts based on certainties and uncertainties are summarized.Then analyzes the existing fuzziness during service process of remanufacturing parts,mainly contain service safety assessment fuzziness and fatigue limit fuzziness, some basic concepts and main principles of fuzzy theory are briefly introduced.Secondly, for remanufacturing structure reliability assessment methods based on fitness for purpose, combined with CEGB R6 failure assessment diagram to combed remanufacturing structure fuzzy failure assessment procedure. By laser cladding experiment, remanufacturing shaping layer performance testing and metal magnetic memory non-destructive testing, analysis remanufactured impeller service safety under speed two different conditions with the measured surface defects.By using the fuzzy mathematical methods of thinking to make security level be further divided and provide a quantitative approach for defect safety degree.Again, the factors which influence the service safety of remanufactured impeller are dynamic,uncertain and pluralistic. Fuzzy comprehensive evaluation method is put forward to evaluate remanufactured impeller service safety. A multi-level evaluation index system was then proposed, which can be divided into remanufacturing process, impeller assembly conditions and other factors. At last, analytic hierarchy process(AHP) and Fuzzy Comprehensive evaluation were combined to evaluate remanufactured impeller service safety.Finally, for classical Miner rule can not take fatigue limit fuzziness and inertia damage between loads into consideration, concepts of remanufacturing blur area and fuzzy inertia fatigue damage zone were proposed and corresponding fatigue damage models were established. Remanufactured parts fuzzy fatigue life prediction model was put forward after coupling the two models and validated the superiority of the model through the empirical analysis, and also proved that fuzzy fatigue life prediction model has a certain practicality in the actual project.