Study On Reliability Optimization Method Of Milling Process Parameters

High speed cutting processes are widely employed in the aerospace,ship building,railway transportation and energy industry,among other fields,because they offer a high precision,high surface quality and high material removal rate.However,in recent years,with the rapid development of modern industry and the ever increasing pressure of market competition,mechanical products have shown a tendency to become more and more special.Yet,complex shapes,thin-walled structures,the use of materials that are difficult to process and high accuracy requirements all increase the probability of the occurrence of vibrations during product processing.This will ultimately affect the processing quality and production efficiency,and reduce the life of the cutting tool and machine.In more serious cases,production accidents might occur and threaten the safety of the personnel and thus the security of the enterprise.The primary purpose of stability analysis of milling is to achieve chatter-free milling.But even in the process of stable cutting,the processing accuracy of the product is still not up to the requirements because of the existence of forced vibration.On the basis of stability analysis,it also needs to analyze the surface position error to improve the performance of the machine.Considering the influence of random uncertainty,this paper proposes the numerical simulation method and the neural network method for reliability analysis of chatter stability and surface location error in the milling.Reliability optimization design of milling parameters are carried out.Main tasks are the following:Firstly,this paper establishes the milling dynamic model.The milling stability and surface location error are predicted by the FDM synchronously,and FDM is compared with SDM and ZOA.The factors affecting the stability of the system are analyzed,and the influence of the various factors on the stability of the system is obtained.Then,considering the uncertainty of random variables,the numerical simulation method and the artificial neural network method for the reliability of stability and surface location error of milling are presented.The effect of random factors on the stability and surface location error of milling is analyzed,which accords with actual engineering situation and provides the quantitative standard for the selection of the actual cutting parameters in different machining conditions.Then the reliability sensitivity of milling parameters is studied,which can put forward reasonable suggestions for the precision control of the machine tools.Finally,taking the milling process parameters,the reliability of chatter stability and surface location error as constraint conditions,and setting up the material removal rate and surface location error as objective function,this paper uses the combination of genetic algorithm and nonlinear programming algorithm to optimize the design,and achieves the anticipated effect.