Experimental Study On Plane Cutting Of Carbon Fiber Honeycomb Composites Based On Dynamic Cutting Angle

Carbon fiber honeycomb composite(carbon fiber honeycomb for short),as a new honeycomb composite material,combines the structural characteristics of honeycomb and the performance characteristics of carbon fiber,has the characteristics of low density,light weight,strong axial bearing capacity and so on,has a wide range of applications in aerospace,marine and other fields.In order to meet the requirements of performance and dimensional accuracy of parts,carbon fiber honeycomb is often needed to be cut,but its structural specificity and heterogeneous materials lead to surface defects such as burr,delamination and ungluing in the processing process,which seriously affect the mechanical properties of parts.In this thesis,the change of dynamic cutting angle during the cutting process of carbon fiber honeycomb was studied.The calculation model of cutting angle was established from the material structure of carbon fiber honeycomb,and the stress state and deformation law of carbon fiber honeycomb wall were analyzed based on the theory of thin plate.The changes of honeycomb wall deformation and surface quality of carbon fiber with different cutting angles were quantitatively analyzed by experimental method.The effects of spindle speed,feed speed and cutting width on cutting force and surface quality were analyzed.Specific research contents are as follows:Firstly,based on the structural characteristics of carbon fiber honeycomb,the cutting angle calculation model of carbon fiber honeycomb was established.The stress state of honeycomb wall before and after cutting with different cutting angles was analyzed,which was divided into the stress parallel to the hole wall and the stress perpendicular to the hole wall.Based on the thin plate theory,the influence law of the stress in two directions on the honeycomb wall deformation was analyzed,and the carbon fiber honeycomb cutting deformation test was carried out.The results show that the maximum deformation occurs when the cutting angle is90°.The effect of cutting angle on honeycomb wall deformation is discussed from theoretical analysis and experimental verification.Then,the carbon fiber honeycomb cutting experiments were carried out.The cutting Angle calculation model was used to obtain the distribution range of cutting angle under different cutting parameters,and the changing law of cutting force and surface topography with cutting angle was revealed.Based on the observation results of surface morphology of carbon fiber honeycomb wall,the out-of-plane damage length was selected as the characterization parameter of surface quality of carbon fiber honeycomb,and the influence of cutting angle on surface quality of carbon fiber honeycomb was quantitatively analyzed.The experimental results showed that: The surface quality of carbon fiber honeycomb wall decreases first and then increases with the increase of cutting angle.The surface quality of carbon fiber honeycomb wall is poor when the cutting angle is 70°-120°.Finally,through the optimization of process parameters to control the cutting angle distribution in a better range,thereby improving the surface quality of carbon fiber honeycomb cutting.The influence of process parameters on cutting force and surface quality was analyzed by taking spindle speed,feed rate and cutting width as experimental variables and combining with the change of cutting angle of carbon fiber honeycomb.The results show that the influence on surface quality is spindle speed,feed speed and cutting width in descending order.Under the experimental conditions of this thesis,the spindle speed of 8000 r/min,the feed rate of 50mm/min and the cutting width of 4 mm can be selected to realize the low damage processing of carbon fiber honeycomb and obtain a better machined surface.