Research On Residual Life Prediction And Evaluation Of Key Parts Of Waste Machine Tools

Compared with traditional manufacturing,remanufactured blanks are used parts.Due to the great uncertainty of the original process,quality and service conditions,the Remanufacturability of used parts varies greatly.The evaluation of Remanufacturability of used parts is the premise of remanufacturing.The prediction and evaluation of the remaining life of used parts is the key to the evaluation of remanufacturability.Therefore,it is of great significance to carry out the research on the prediction and evaluation of the remaining life of used parts for realizing energy conservation and resource reuse.The research topic of this paper comes from the "Green Remanufacturing System Integration Project" supported by the Ministry of Industry and Information Technology of China Made 2025,which is "Key Technologies and Application Demonstration of Machine Tool Green Remanufacturing".Based on the actual data provided by Shenyang Machine Tool Co.,Ltd.,the prediction and evaluation of the remaining life of the spindle of waste machine tools are studied in depth.The main research contents are as follows:(1)The existing prediction model is predicted based on the S-N curve of the base material,not on the fatigue life curve of the actual parts.This paper proposes a method to obtain the fatigue life curve of the waste machine tool’s spindle.The spindle of the waste machine tool is processed into several fatigue specimens,and the SN curve based on the actual parts is obtained by tension-compression fatigue test.(2)For the fracture mechanics,the continuous fatigue damage model is mainly used,but most of the continuous fatigue damage models do not consider the crack closure effect.This paper puts forward a method to modify the continuous fatigue damage model based on it.Based on the non-linear continuous fatigue damage model proposed by CHABOCHE,the effective crack growth factor is added to modify the model and the remaining life evaluation model for the spindle of waste machine tools.The important parameters of the formula are not calculated by systematic and standard methods.Solution.This paper proposes a method based on least squares method to achieve nonlinear fitting through python programming to obtain the parameters in the model.(3)For the load loading sequence,the crack closure factor will be affected and the remaining life prediction result will be inaccurate,this paper proposes a method to modify the prediction and evaluation model of remaining life ofwaste machine tools with the effective crack growth factor.The effective crack growth factor in the model is modified by considering the loading sequence,and the model is obtained by a two-stage loading fatigue test.In order to validate the prediction accuracy of there maining life evaluation model of the spindle,the spindle of the waste machine tool has been in service.Taking the main shaft of the CAK5085 waste machine tool of Shenyang Machine Tool Co.,Ltd.as an example,the fatigue life curve is obtained by fatigue test.Secondly,the model is corrected to obtain the remaining life model of the machine tool spindle.Finally,the fatigue test data and model calculation are used to verify the validity and feasibility of the model.The result provides an effective way for the remanufacturability evaluation of used machine tools.