Investigation and optimization of biaxial fatigue behavior of aluminium alloy wheels

Wheels, one of the most important safety parts of the vehicle, are vital parts because they operate under static and dynamic loads. Therefore, during the design process, it is analyzed according to the maximum loads that will occur on the wheel according to the vehicle characteristics, automotive standards and test specifications. Wheels, designed by taking into account the mechanical analysis, are subjected to mechanical tests after sample production. Biaxial fatigue (Zwarp) test, dynamic cornering fatigue test, radial fatigue test, vertical impact test, 13° impact test are some of the mechanical tests. Variable loads that reach the critical number of repetitions can cause fatigue damage to the wheels. Within the scope of this study, fatigue behavior of wheels in variable road conditions was investigated in accordance with SAE J2562 biaxial fatigue (Zwarp) test standard. Experimental designs were prepared with Minitab statistical program and analyzed with LBF.WheelStrength engineering software. The effect of 16 geometric parameters such as spoke pocket dimensions, spoke thickness, wheel bolt position, which affect the biaxial fatigue strength of the wheel, were examined and the effective parameters were optimized to provide minimum stress - weight. In order to verify the finite element model, the experimental biaxial fatigue test of the wheel was carried out on the test bench of CMS Wheel company according to the SAE J2562 standard under the same boundary conditions. With the design improvement in the model with fatigue cracking, the maximum stress value was reduced and appropriate results were obtained from the test with minimum weight.