Design Of Hybrid Carbon Fiber Composite Automotive Drive Shaft

Carbon fiber composite material has high strength, light weight, anisotropy, etc. Inthe automotive industry, carbon fiber material is often used to manufacture the bodysurface cover to replace the traditional metal sheet metal parts; or to make complexshapes aerodynamic components to improve the car’s power, control and so on. With thedevelopment of light weight in the automotive, how to reduce vehicle weight whileimproving its performance has become an issue of major vehicle manufacturers. For thetraditional rear-wheel drive or four-wheel drive passenger car, the main drive shafts aregenerally steel shafts, but a longer steel shaft’s bending natural frequency always under150Hz, cannot meet the vehicle requirements at high speed due to the limitations of steelmaterial properties. A two-piece drive shaft connected with universal joints should beused to be fixed to the vehicle body bracket. This makes the steel drive shaft structurecomplicated and heavy. The universal joints will wear and bring out abnormal noise orvibration after being used for a long time. In order to solve these problems, the engineershave been trying various methods. With the lightweight aluminum alloy and carbon fibercomposite material used in combination, the one-piece lightweight automotive driveshaft could be made to meet the use requirement. A new way is provided to solve theabove problems.This paper has designed a hybrid carbon fiber composite automotive drive shaft. Theouter layer of the hybrid drive shaft is aluminum T6061-T6, it is mainly used to transfertorque, also protects the inner layer of carbon fiber material; the inner layer of the hybriddrive shaft is carbon fiber material URN300, it is mainly used to increase the naturalfrequency of the hybrid shaft; the glass fiber material GEP215is used between aluminumand carbon fiber layer, which can reduce the residual thermal stress effectively betweenaluminum and carbon fiber layer to ensure the carbon fiber plies are hard to be damaged.This paper mainly studies the statics performance and natural frequency characteristic of the hybrid drive shaft, designs the connection between the drive shaftand universal joints. In the statics analysis of hybrid shaft, firstly determines the specificsize of shaft according to the requirements; and then uses the ANSYS Workbench and theACP function module to analysis the hybrid shaft maximum stress, maximum shearstrain and other parameters, while analysis these parameters of the same size purealuminum shaft as the basis for comparison. Then experiment with bending and twistingcombined test table and the strain gauge, tests the maximum shear strain of purealuminum. Lastly experimental results and simulation results should be compared toverify the statics performance of hybrid drive shaft whether meet the requirement. Thesecond part is studying the natural frequency characteristics, uses finite elementsimulation to analyze natural frequency characteristic of hybrid and pure aluminum shaft,finds the relationship between the natural frequencies of two kinds of shaft. The thirdpart is designing a connection to connect shaft and universal joint. In order to avoiddrilling on the shaft, reduce the assembly difficulty choosing tooth type connection. Inthe design of the tooth connection, according to the theory and performance requirementsto determine the size and the number of teeth, and then use the simulation analysis toobtain tooth connection’s maximum normal stress and maximum shear stress. Lastly thestrength of the connection should be checked.The results show that statics performance’s test data and simulation data arebasically the same, confirming the idea that outer aluminum shaft bears the most torque.So the statics performance of hybrid shaft meet the use requirement Modal analysisshows that when laid angle of carbon fiber layer is0°, the natural frequency increases by44%to328Hz relative to the pure aluminum shaft; but it is not obvious for multi-plycarbon fiber to improve the effect of the natural frequency. The analysis results of toothconnection show that: when the tooth length is60mm, height is1mm, width is6.4mmand the number of teeth is20, the connection can satisfy the requirements and make it novery hard.The research provides a theoretical basis for the carbon fiber hybrid shaft’s design and manufacturing, the weight of hybrid transmission shaft designed decreased by40%compared with steel drive shaft, which has a positive significance in simplifying thestructure of automotive transmission system and reducing the weight of the car.