Residual Fatigue Life Prediction And Redesign Of Scrap Automobile Engine Crankshaft For Remanufacturing

At present,the automobile manufacturing industry in China has entered a sustained and rapid growth period,causing the number of abandoned cars increasing year by year.Thus,many environmental problems such as environmental pollution,resource exhaustion and land occupation are becoming more and more serious.These problems can be effectively alleviated by reasonable recycling and utilization of scrapped automobiles.And remanufacturing is one of the keys to realize the recycling of the scrap car.How to evaluate and improve the remanufacturability of key auto parts is a key problem that needs to be solved urgently in the remanufacturing field of scrapped automobiles.Fatigue failure is a common form of failure in automobile parts,but it is difficult to be observed in parts.In order to ensure the quality of remanufactured parts,the residual fatigue life prediction is important for judging the remanufacturability of scarp auto parts.Therefore,this paper focuses on the residual fatigue life prediction and the design for remanufacture.The research status of remanufacturing,remanufacturing evaluation,fatigue life prediction and design for remanufacture of scrap auto parts at home and abroad is analyzed,and the specific research route and research contents are put forward.Taking the crankshaft of Wuling light automobile engine as the research object,the automobile engine is dismantled.Moreover,the crank and connecting rod is mapped and the assembly model is constructed by using 3D drawing software UG.The prediction method and model of residual fatigue life of crankshaft are put forward based on rigid flexible coupling simulation method according to the actual working condition of engine crankshaft and the rigid flexible coupling theory basis.The crankshaft modal stress of the scrap engine is calculated based on the finite element method,and the combined dynamic simulation method is used to obtain the rigid flexible coupling simulation load spectrum of the crankshaft.Finally,the fatigue life prediction of crankshaft is carried out by using FE-SAFE.In addition,the evaluation index of the material's selection is identified by the quality function deployment(QFD),and the index system of crankshaft materials' selection is constructed.By using the analytic hierarchy process(AHP),the crankshaft redesign for remanufacturing is realized via selection of material.In this paper,the crankshaft overall analysis is used to reflect the stress status of the crankshaft,and the rigid flexible coupling simulation method is proposed.The rigid flexible coupling simulation model of the crankshaft system is generated by the flexible body generation technology,which greatly improves the prediction precision of thecrankshaft life.The crankshaft design for remanufacturing based on material selection improves the remanufacturability of crankshaft to facilitate its reuse after end of life.