Truck tire/pavement interaction analysis by the finite element method

A simulation is developed for study of interactions between a rolling truck tire and a rigid pavement structure. A three-dimensional finite element method is required to solve this nonlinear dynamic contact problem. The ABAQUS finite element code is employed. A Goodyear 295/75R22.5 Unisteel G167A Low Profile Radial smooth tire is modeled to roll over the rigid pavement. Fiber reinforced composite model and rubber material model is utilized to simulate the real tire structure. The Coulomb friction law is used to study the contact between the truck tire and pavements. Different tire pressure levels, load levels, moving speeds, slip angles, braking or traction, and friction are applied in the simulation. Results for a static loaded tire against a rigid flat plate are compared with experimental data from the literature. Contact stress distributions and contact areas for the rolling tire over the rigid pavement at various conditions are presented.; Results from this investigation lead to the following observations and conclusions: (1) For a free rolling tire model, normal stress contours of the free rolling tire model are shifted forward; high stress areas are moved toward to two sidewalls; high stress areas are increased in fore-back direction; normal maximum stresses at higher tire pressure (100 psi and 110 psi) are higher than for the static loaded tire. (2) For a free rolling tire model at a deflection of 50 mm and a speed of 65 mph, the ratio between the maximum stress and the average static average is above 2.0 at 100 psi and 110 psi. (3) For traction or braking tire models, normal stress contours for the traction models are shifted forward more than for the free rolling model; normal stress contours for the braking models are shifted backward. (4) For traction or braking tire models, contact areas are larger and contact stress are higher than for the free rolling model. (5) For the slip-rolling tire model, high stress areas are moved toward the sidewalls in the slip direction. The contact areas are smaller than for the free rolling model. The maximum normal stresses are higher than for free rolling models and traction or braking models. (6) For the slip-rolling tire model, a larger slip angle produces higher normal stress and shear stress. (7) The maximum ratios of max/av. stress vary from 1.98 for static case to 1.97 for the free rolling case, and 3.22 for the traction case to 3.29 for the slip rolling case. These findings suggest that the average stress used in the AASHTO seriously underestimates the maximum stresses served by pavements, with the result that highways can be seriously underdesigned.