Dynamic Load Identification And Reliability Evaluation Of Driving Axle Housing Of Light-duty Truck Exposed To Random Road Excitation

As a significant load-bearing parts of trucks, driving axle housing connects the body and the tire, transmitted the random load in all directions from the tire. The fatigue damage is one of the main failure modes of the axle housing due to the bad working conditions. To enhance the power performance, the fuel economy, steering stability, the comfort performance of the vehicle, and save the cost of materials, how to do the structure optimization design on the basis of the fatigue reliability of the axle housing is a key problem at present stage. Traditional reliability designs are mainly the road test, car bench test, which cost higher and the effect of solving the fatigue damage of the axle housing is not ideal. Therefore, how to get the real load spectrum and to do the fatigue reliability assessment of the axle housing under the random excitation of the road are the key issues in the research work.The paper takes the driving axle housing for example, analyzing and optimizing the fatigue reliability of driving axle housing exposed to the random road excitation. Firstly, a parametric finite element model of driving axle housing of light-duty truck was established with ANSYS. Taking the driving cycles for example, analyzed the magnitude of load spectrum which is between the tire and the ground in the conditions of variable speed. By using the transfer function and relevant formula, the dynamic response characteristics of the axle housing under the random road excitation was obtained. The stress of the axle housing was received through random vibration analysis in ANSYS.On the bases of the above work, Goodman criterion the S-N curve of the different material of the axle housing was modified with Goodman criterion. The cumulative fatigue damage of the axle housing under cyclic conditions was calculated and analyzed and its fatigue reliability was evaluated based on the Miner cumulative damage criterion. Optimized design of axle housing structures has been done finally for the constraints of fatigue reliability of the axle housing within a certain mileage by using the optimized analysis function of ANSYS, which adjusted the structure of the axle housing and improved the fatigue reliability of the axle housing and the results meet the requirements. Relevant methods for the reliability design of the car components has a certain reference significance.Finally, some parameters such as the truck speed, road roughness and the magnitude of load of truck were discussed in the influence of the fatigue life of the axle housing. The conclusion has a certain reference significanceBased on APDL code of ANSYS and VC++program design language, the parametric design platform of driving axle housing has been established. Using the simple and convenient operation menu allows the user to complete a series of processes from modeling to analysis. The result of the model, analysis, stress nephogram. and optimization could be displayed on the screen through the resulting menu. The establishment of this platform saves time of analysis, improves the work efficiency in the development and design of axle housing.