Prediction of Wheel Traveling Performance Using Ground Contact Stress Models

In order to analyze the traveling performance of a wheel from the distribution of ground contact stresses, Gaussian functions were applied to the modeling of the respective normal and tangential stresses. The two functions were superposed to fit the distorted shape of the normal stress curve at a high slip ratio. The previous model over-predicted the tangential stress at low slippage and modifications in the proposed model were developed through consideration of relative slip at the contact surface. Unknown coefficients in the model can be expressed by linear and cubic functions of wheel sinkage. Based on the results, the stress model was extended to apply to arbitrary sinkage. The new model fitted very well to measured tangential and normal stresses. Drawbar pull, torque and rolling resistance could also be estimated with high accuracy.