A LIFE EVALUATION METHED FOR FRONT AXLE BASED ON FRONT AXLE DYNAMICS MODEL

In view of the difficulty of obtaining durability test specifications for axle components, a method of constructing driving load of the front axle dynamic model was proposed to provide the input for system-level bench test and life verification of front axle components. The life of front axle was obtained based on the whole vehicle dynamics model and the measured road load, and the useful information and life prediction results in the above process were employed to guide the construction of driving load applied on front axle. Firstly, the frequency band of the measured six-component forces at the wheel center was adjusted. Then, with the goal of minimizing the difference between the damage/life of the front axle and the reference value under each working condition, the adjustment coefficient of the amplitude of the three-way forces at the wheel center was optimized by combining the response surface method and genetic algorithm. The optimized three-way forces at the wheel center and the other three-way torques constituted the driving signal of the front axle model. The results show that the constructed wheel center drive signal is used to simulate the dynamic load of the front axle model. The life of the front axle, the failure sequence of risk points and the damage contribution ratio of various road conditions to dangerous points are obtained and in good agreement with the reference results, which verified the effectiveness of the proposed method and provided reference for the drive signal construction and component life evaluation of system-level bench durability test. Finally, the damage distribution of the front axle can be consistent with the reference results by modifying the main damage load of the shaft tube.