Catastrophe Modeling Of Chip Flow Angle In Cylindrical Cutting With 2d Cutting Deformation Parameters And Research On The Experimental Phenomena

It has been found that in the non-free cutting process,when the cutting parameters continuously change along a certain path,the chip flow angle will abruptly change from a certain value to another value,accompanied by a decrease in cutting power.This phenomenon has great application potential but cannot be explained by traditional cutting theory,so it is necessary to lucubrate.Cylindrical turning is a type of double-edged non-free cutting commonly used in production and processing.Mathematical modeling of the catastrophe of chip flow angle during cylindrical turning is used to explore the mechanism of the catastrophe of chip flow angle and to predict the critical conditions.It is of great significance in both theoretical research and practical application.The main contents of this paper are as follows:Firstly,the simulation data of shear angle,friction angle and shear stress during the 2d cutting deformation process of 6061 aluminum alloy workpieces were obtained by finite element simulation,and the empirical formulas of these 2d cutting deformation parameters are fitted accordingly.Secondly,based on the shear plane theory,the cutting model of the double-edged turning tool with arbitrary tool angle and tool nose radius is established under the assumption that the chip does not bifurcate.The cylindrical turning power function is derived by introducing the fitted empirical formulas of 2d cutting deformation parameters.Based on the cutting power function,a mathematical model of the catastrophe of chip flow angle is established,and the prediction of the critical conditions is realized.The mechanism of the catastrophe of chip flow angle is analyzed,as well as the influences of the main declination,the declination and the radius of the tool nose on the catastrophe of chip flow angle.Thirdly,through the cylindrical turning experiment of the 6061 aluminum alloy workpiece moving the cutting tool in the oblique direction,the continuous variation of the control parameters along a certain path is realized.Phenomenons of the catastrophe of chip flow angle and the chip bifurcation were observed in the experiment.The theoretical prediction value of the critical conditions is in good agreement with the experimental value,thus verifying the effectiveness of the cylindrical turning chip angle catastrophe model.Finally,a preliminary analysis of the mechanism of chip bifurcation observed in the experiment was carried out.It is concluded that the chip interference during non-free cutting is the root cause of the chip bifurcation phenomenon,and the chip bifurcation phenomenon does not occur in the two types of free cutting processes without chipping interference.