Research On Finite Element Analysis And Experiment Of Drilling Of Carbon Fiber Reinforced Polymer Composites

Because of the excellent mechanical properties, CFRP is being widely usedin military, aviation and various fields of civil industry. However, it is confrontedwith a lot of problems due to the anisotropy of CFRP in the process, especiallydrilling, which is prone to delamination, burrs, tear and other defects. Besides,high hardness and poor thermal conductivity of the materials lead to tool wearand failure in the drilling. These problems seriously affect the high-quality andhigh-efficiency machining of CFRP.Aiming at the existing problem of CFRP machining, the paper adopts twodifferent characteristics of cutting tools for drilling experiments based on cuttingmechanism and by means of the finite element method to comparatively analyzecutting forces, tool wear and the quality of machining holes during the drillingprocess. The main contents of this paper include:First，the binary cutting mechanism of unidirectional CFRP is studied.Cutting deformation and chip formation of the cutting process are analyzed andthe relationship between the chip formation and fiber orientation angle arediscussed. On this basis the theoretical formula of cutting force is deduced andthe types of the defects of hole machining is analyzed in the light of thecharacteristics of traditional drilling method.Then, the finite element model of cutting process is established and thevalues of force and torque under the condition of3000rpm spindle speed and210mm/min feed rate is analyzed by Deform-3D.Secondly, through the CFRP drilling experiment, the regression model ofaxial force of PCD drill and diamond-coated drill is established under different cutting parameters and the binary empirical formula and the variance is obtained.Moreover, the unitary empirical formula is obtained by simplifying. Finally, thevariation of the axial force are analyzed.In the end, the PCD drill and diamond-coated drill wear mechanism isanalyzed. The wear of two kinds of drill are compared and the quality ofmachining holes is analyzed at different cutting parameters. The PCD drill isproved more suitable for CFRP machining. Through the study of exit burr defects,it analyzes the mainly reason of defects occur.