Simulation and Test Correlation of Wheel Radial Fatigue Test

The Radial fatigue test is intended to find the structural performance of a wheel for normal highway use on passenger cars, light trucks and multipurpose vehicles. The wheel has to withstand repeated radial loading for a defined number of cycles in order to pass the test. The fatigue life of a wheel subjected to the repeated loading is calculated from the stress values obtained from static analysis. The accuracy of stress value depends on various parameters like tire modeling, simulation methods, load applications etc. This paper describes the tire finite element model representation and its validation, radial fatigue test simulation process and the physical testing correlation. Tire vertical stiffness plays a vital role in the radial test as the tire transfers the load from driven drum to the wheel. Tire vertical spring rate testing is done as per the SAE J2704 standard and the same condition has been simulated in CAE. The tire material properties are tweaked to match the vertical stiffness test curve. The radial fatigue test is simulated in static condition as per SAE J328 standard using the validated tire model. Simulation stress values close to the lab strain gauge measurements and thus giving confidence in predicting the life estimates of the Wheel.