Study On High Quality Pore-making Technology Based On Aramid Fiber Reinforce Resin Matrix Composites

Aramid reinforced resin matrix composite materials are increasingly widely used in aerospace,special protection,industrial manufacturing,transportation and other fields.Its high strength,high toughness,low density,fatigue resistance,corrosion resistance,impact resistance and other characteristics are not available to other materials.In the subsequent use of aramid fiber reinforced resin matrix composites,it is usually necessary to carry out mechanical processing,especially when assembly and connection are required,holes are usually made on it.However,the high toughness,non-uniformity and anisotropy of arnylon composite materials will make it easy to appear in the machining process,which seriously affect the service life of the workpiece and the use effect of burr,tearing,delamination and other processing defects.In this paper,aiming at the hole making defects of aramid fiber reinforced resin matrix composites,the spiral milling and drilling technology were used for hole making experiments,and the kinematics and cutting force of spiral milling were studied deeply.Based on the mechanism study,the optimal combination of spiral milling parameters was studied,so as to realize the high quality hole making of aramid fiber reinforced resin matrix composites.The preparation and application of aramid fiber and its composite materials and the research status of pore making at home and abroad were summarized.Based on the single cell structure,the stiffness matrix of plain braided plate was calculated by the classical laminate theory,and the equivalent model of arylon fiber reinforced resin matrix composite plate with plain braided structure was established.ANSYS Workbench 18.0 was used to build a finite element model to simulate the state of aramid fiber fabric/resin laminates under static action,and further analyze the situation of defect failure caused by mechanical damage of composite materials.Based on the research of drilling process and cutting force,the formation of hole defects of arylon fiber reinforced resin matrix composites was analyzed,and the corresponding defect damage evaluation method was given,which provided theoretical guidance for evaluating high quality hole making process.The group composition,surface morphology,tensile strength of monofilament and interlaminar shear strength of aramid reinforced epoxy resin composites were studied by CaCl2 ethanol solution and LiCl ethanol solution at different concentrations and treatment times.The surface morphology,chemical elements and chemical groups of aramid fiber were characterized by scanning electron microscopy,Fourier transform infrared spectroscopy and X-ray electron spectroscopy,and the best treatment conditions were found.The aramid fiber/epoxy resin composite was prepared by hot pressing method with aramid fiber and epoxy resin,and the shear tensile strength of the fiber and epoxy resin was tested.By analyzing the interlaminar shear strength,the mechanical properties of fibers and the interfacial bonding properties of composites were studied.According to the machining principle of spiral milling,considering the effects of tool rotation,revolution and axial feed on machining quality and cutting force,as well as different fiber treatment methods,orthogonal comparison experiment was designed.Through the cutting force model,the mechanism of hole making is analyzed theoretically.The essential difference between spiral milling and twist drilling is studied theoretically.Based on the test results of cutting force and hole making quality,the influences of machining technology and machining parameters on cutting force and hole making quality were analyzed,and the processing methods and technological parameters suitable for making holes of arylon fiber reinforced resin matrix composites were determined.