In-service Remanufacturing Timing Decision Method Of Machine Tool Spindle Based On RUL

In-service remanufacturing is an important part of green manufacturing and sustainable development.In-service remanufacturing of machine tools is the best way to reduce resource waste,extend service life and realize resource recycling.As a key component of machine tools,the spindle has complex and changing service conditions,changing environment,slow performance degradation and not easy to monitor,which makes it difficult to determine the timing and accuracy of in-service remanufacturing.Therefore,how to determine the best time to remanufacture the machine tool spindle in service is the key to obtain the best economic benefits and performance of remanufactured machine tools.Based on this,this topic takes a certain type of machine tool spindle as the research object,analyzes the remaining life and performance degradation of the in-service machine tool spindle,and systematically studies the method of determining the in-service remanufacturing timing of the machine tool spindle.(1)To solve the problem of difficult to predict the remaining life of in-service machine tool spindles due to the service conditions and the uncertainty of their quality,an improved nonlinear fatigue cumulative damage spindle life prediction model was constructed based on the interaction between the service loads of machine tool spindles,and the accurate spindle S-N curve was obtained by using spindle wire-cut specimens for tensile and compressive fatigue experiments.The validity of the prediction model was verified,which solved the problem of difficult to accurately predict the remaining life of machine tool spindles and realized the accurate assessment of the remanufacturability of in-service machine tool spindles.(2)To address the problem of difficult to determine the inflection point of spindle performance degradation due to the uncertainty of the in-service machine tool spindle quality and service conditions,the performance degradation mechanism of the machine tool spindle was investigated,and a two-stage Wiener process degradation model was constructed for the in-service machine tool spindle considering the inflection point of performance degradation,based on which a reliability function based on the two-stage Wiener process degradation model was derived,and SIC was applied to determine the inflection point of spindle performance degradation.SIC was used to determine the inflection point of spindle performance degradation;a time domain selection mechanism was established to determine the time domain of spindle remanufacturing,which provides the premise for the establishment of a multi-objective optimization model for the best time for remanufacturing.(3)To address the problem that there were many factors influencing the remanufacturing timing decision of in-service machine tool spindles and it was difficult to determine the remanufacturing timing due to the coupling of multiple factors,a remanufacturing timing decision method for in-service machine tool spindles based on a weighted optimization framework was proposed.A multi-objective remanufacturing timing decision model was constructed based on the service value and cost of the spindle during its life cycle,and a model solving algorithm based on the weighted optimization framework was proposed to solve the problem of conflicting and difficult to determine the in-service remanufacturing timing decision of the machine tool spindle.