Impact of Road Roughness on Tire-Pavement Contact Stresses during Vehicle Maneuvering

The deterioration of the US transportation highway network and the onset of new technologies in the freight industry are expected to cause changes in the axle load magnitude and distribution, further exacerbating the reduction in the service life of flexible pavements. In this study, a reviewed framework to incorporate roughness-induced dynamic wheel loading into tire-pavement contact stress prediction is presented. The response to nonfree-rolling conditions, usually overlooked, was considered. State-of-the-art numerical models were used to account for pavement unevenness, vehicle dynamics, and 3D and nonuniform contact stresses. In this framework, for a given target international roughness index, an artificial multitrack roughness profile was converted into a dynamic loading profile based on the mechanical properties of a Class 9 vehicle. Upon discretization of the dynamic loading profile into a finite number of loads based on percentile distributions, a 3D finite element model of a dual-tire assembly was used to predict the contact stress distribution over a rigid surface. The performed numerical simulations allowed us to analytically quantify the variation of vertical and in-plane contact stress distribution. Hence, changes in the stress/strain field distribution and peak values under various axle loading scenarios were determined. The findings reveal that disregarding the effect of road roughness and vehicle maneuvering could result in considerable underestimation of the net forces and contact stress distribution developed at the tire-pavement interface. These considerations are particularly impactful on in-plane contact stresses, which, in turn, are associated with near-surface distresses.