Machining Variation Of Arm Thin Wall Parts Based On High Speed Milling Process Optimization Of Shape

With the vigorous development of China's aerospace industry,the performance demand of parts in this field is also constantly increasing,and thin-walled parts are widely used due to the characteristics of small weight,high specific strength and good structure.At the same time,the thin-walled parts themselves with certain defects,such as low stiffness,poor processing performance.Therefore,in the actual process of processing,thin-walled parts are easy to deformation,can not ensure the accuracy of processing.In view of the above problems,this paper combined with its own subject,taking a certain type of arm thin-walled parts as the research object,and put forward corresponding solutions.The main research contents are as follows:(1)Based on high speed cutting technology and metal cutting theory,to a certain type of arm thin-walled package as the research object,this paper introduces the components of the material properties,processing characteristics,technique requirements,a detailed analysis of the parts in the process of high speed milling milling force,milling and milling deformation,and made a perfect optimization strategy for the milling parameters,lay the foundation for subsequent research.(2)According to the constitutive model,chip separation criteria,and critical theory,the relations between friction using Abaqus finite element software to establish the threedimensional model of milling thin-walled arms,analog simulation to get the stress and strain nephogram and milling force,the workpiece deformation graph,analyze the change rule of them to explore,discover:processing start and end stage,the stress is relatively large,relatively stable intermediate process;The strain is mainly concentrated in the thin-walled edge area.The three-direction milling force is the largest in X direction,followed by Y direction,and the smallest in Z direction.The deformation was also mainly concentrated in the thin-walled edge region and the shape variable of the middle part was small.(3)Adopt orthogonal experiment method to design and carry out milling force experiment,and collect milling force value and workpiece deformation by force meter and coordinate measuring machine respectively.The empirical formula of milling force is established by using the obtained milling force value data,and the influence of milling parameters on the workpiece deformation is investigated by analyzing the deformation data of the workpiece.The results show that:the increase of feed,back draft and milling width will increase the workpiece deformation,and the increase of milling speed will reduce the workpiece deformation.(4)Combined with BP neural network theory,the network was trained and tested by using the data obtained from finite element simulation model,and the nonlinear mapping relationship between milling parameters and workpiece deformation was constructed.Aiming at machining to minimize deformation,and combined with BP neural network model using the algorithm of fireworks optimize the milling parameters,get ideal milling parameters and compared with the experiment and simulation,the optimal parameters of the comparison,the results show that the fireworks algorithm to optimize the milling optimum parameters is compared with the experiment,the optimal parameters of the workpiece deformation decreased by 58.1%;Compared with the optimal parameters of simulation,the deformation of workpiece decreased by 31.2%.Therefore,the milling parameters optimized by firework algorithm and BP neural network model meet the expected requirements.