Structural Optimization And Performance Evaluation Of Carbon Fiber Composite Materials Automotive Driveshaft

In this paper,the background of light weight car.For mass production models,the carbon fiber composite materials driveshaft was prepared through the structural optimization and the performance evaluation.The rapid prototyping and winding resin characterization and selection were carried out by DSC(differential scanning calorimetry),rheological testing,universal testing machine and thermogravimetric analyzer.The effect of different fiber angles and diameters on the modal of carbon fiber composite shafts was studied by using the theory of classical laminates.The relevant technological research was carried out in combination with the finite element method.The optimization of the structure of the composite shaft was carried out.The microscopic and mechanical properties of carbon fiber composite shafts were characterized by scanning electron microscopy(SEM),static torsion,natural frequency test,critical speed test and metallographic microscope.In terms of raw material performance evaluation.The curing conditions of two-component X4201A/B epoxy resin and one-component BAC 177 epoxy resin were determined by constant temperature and temperature-rising DSC(differential scanning calorimetry).The curing conditions were 50?/200min+86?/70min+127°C/ 40 min and 77°C/130min+103°C/50min+146°C/30 min and a glass transition temperature of 126°C and 155°C,respectively.Through the rheological test to determine the X4201A/B and BAC 177 processing temperature control at 40?and 60?.The tensile strength,tensile modulus,flexural strength and impact strength of X4201A/B and BAC 177 epoxy resin were 69 MPa,2.98 GPa,125MPa,15.84KJ/m2 and 71 MPa,2.92 GPa,120MPa,14.44KJ/m2 respectively by universal testing machine.The decomposition temperatures of X4201A/B and BAC177 were 255? and 350? respectively by TG(thermogravimetric analysis).The tensile strength,tensile modulus and interlaminar shear strength of carbon fiber composites based on BAC177 epoxy resin were tested by universal testing machine,which were 123 GPa,1.6GPa and 55 MPa.The volume fraction of the NOL ring fiber was 56%,and the cross-section of the fiber was observed by scanning electron microscopy(SEM).It was found that the bonding property between resin and fiber was good,which satisfied the research on the forming technology of automobile transmission shaft.In terms of driveshaft structure optimization design.The three-dimensional mathematical model of the steel automobile transmission shaft and the metal flange fork structure with inner diameter of 50 mm,70mm and 80 mm were established by using CATIA.The finite element analysis software ANSYS Workbench was used to establish the finite element model of the drive shaft.Modal analysis,the six-order modal frequency and modal shape of the steel driveshaft are obtained.The natural frequencies of the drive shafts of carbon fiber composite materials are reduced with the increase of angle.The results show that the natural frequency of carbon fiber reinforced composite shafts increases with the increase of inner diameter,and the inner diameter of 70 mm and 80 mm carbon fiber composite shafts of the composite shafts with different inner diameters are laminated.The natural frequency is greater than the steel shaft,you can reach the critical speed shaft performance requirementsIn terms of driveshaft forming and performance evaluation.The natural frequencies of the carbon fiber composite shafts of 50 mm,70mm and 80 mm are 64.38 Hz,76.25 Hz and 80.00 Hz respectively.The ratio of the simulation frequency to the measured frequency is 2.4,2.1 and 2.1,respectively,and the results tend to be Stable,can be measured by the actual simulation of the actual product to determine the natural frequency.The critical speeds of the shafts with inner diameters of 50 mm,70mm and 80 mm are 3500r/min,4300r/min and 4400r/min,respectively.The ratio of critical speed to theoretical critical speed is 90.6,93.9 and 91.7 respectively,The result is about 90% of the theoretical critical speed,which is within the normal error range.The fiber-reinforced composite shafts with different inner diameters were fabricated by filament winding process,and their properties were evaluated.The static torsion test showed that the torque of the 50 mm and 80 mm drive shafts was 2525 NM and 6062 NM,respectively.The dynamic unbalance of the drive shaft is controlled to 260 gmm by dynamic balance calibration.The results of metallographic microscope show that the distribution of fiber and resin is uniform,which meets the requirements of stable and batch winding forming technology.