Effect of material and spoke pattern on the strength and fatigue life of automotive wheels

Wheels play a crucial role in ensuring the safety and comfort of passengers in automotive vehicles. Their durability is significantly influenced by both the material composition and spoke pattern design. This study numerically examines the impact of wheel material and spoke configuration on mass, von Mises stress, deformation, and fatigue life using ANSYS Mechanical, a commercially available finite element analysis software application. Three materials—Al 7075-T6, Al 7075/BN/Al₂O₃-T6, and Mg AZ91D—were analyzed alongside eight different spoke patterns. To determine the optimal combination, a two-step optimization process was employed. First, a fixed spoke pattern was evaluated across the three materials, with the best material selected using a scoring method incorporating mass, stress, and deformation. The chosen material was then applied to all spoke designs, and the optimal configuration was identified using the same evaluation approach. The fatigue life was estimated based on the modified Goodman failure criterion, showing close alignment with theoretical predictions, with a maximum deviation of 11.30%. The results indicate that Mg AZ91D is the most suitable material, while the spoke design labeled model 3 achieved the lowest score of 28.17, making it the most optimized. However, model 5, which had the second-lowest score (29.53), exhibited the highest fatigue life of 2.14 × 10⁶ cycles—79.83% greater than that of model 3.