Modeling Of Cutting Force And Analysis In Helical Milling Of CFRP With Ball End Milling Cutter

Helical milling hole is a kind of hole-making technology suitable for typical difficult-to-machine materials.In the process of helical milling,the cutter rotates around its own axis and carries out helical feeding at the same time.In the process of drilling,the cutting force can be reduced,and the wear condition of the cutter and the quality of the hole can be improved.With the development of science and technology,carbon fiber reinforced polymer(CFRP)has been widely used in aviation field,and the problems of hole-making quality and tool wear have become increasingly prominent.As an important parameter in the process of machining,the cutting force is directly related to tool wear and hole quality.Therefore,in this paper,the cutting force and related basic problems in the helical milling process of carbon fiber reinforced composites are studied by using ball-end milling cutter.The main research contents are as follows:(1)Based on the kinematics characteristics of the helical milling process and the geometric shape of the ball-end milling cutter,and based on the classical mechanical cutting force model,an analytical model of the cutting force in the helical milling process of the ball-end milling cutter is constructed.The model integrates the effects of the tool rotation,the rotation around the hole center and the axial feed,and considers the cutting effect of the bottom edge of the cutter and the composite material in the helical milling process.The anisotropy improves the cutting force model.(2)A test platform for helical milling holes was set up,and experimental study on helical milling holes of carbon fiber reinforced composites with ball-end milling cutters was carried out.Three-dimensional cutting force signals under different cutting parameters were collected during the experiment,and the influence of cutting parameters on three-dimensional cutting force was analyzed in detail.The results showed that the influence of cutting parameters presented typical non-linear characteristics.The influence of ball-end milling cutters on composite materials was analyzed comprehensively.The relationship between cutting parameters,tool wear and hole-making defects was analyzed.(3)Based on the response surface method,the cutting force is studied and the extreme value of cutting force is predicted.According to the cutting force measured by the helical milling hole test,the instantaneous coefficient method is used to identify the cutting force coefficient and the cutting force of helical milling hole of composite material under different cutting parameters is simulated by using the identified cutting force coefficient,which verifies the cutting force.The correctness of the analytical model and the prediction of the cutting force coefficient by using the neural network model make the cutting force model more applicable.The research results have positive guiding significance for further understanding the nature of helical milling holes of carbon fiber reinforced composites and their industrial application.