Numerical Simulation Of Interaction Between Tire And Asphalt Pavement

In existing asphalt pavement design criterion in China, the of interaction betweentire and pavement is simplified as double-circle uniform load, and the road structure issimplified as a multi-layered elastic analysis system. However, the analysis of pavementunder static double-circle uniform load ignores the dynamic effect of tire load and3Dnon-uniform distributed property. The asumption of multi-layered elastic analysissystem is only suitable for the situation when the temperature is low and thedeformation is small while the pavement is a viscoelasticity system in most time. On theother hand, The deflection serves as the index of the pavement structure whole rigidity,using tensile strains at the bottom of asphalt layers and the semi-rigid base as designindex to control fatigue cracking in criterion. Although these indicators to some extentreflect the mechanical response of the pavement, rutting and transposition andupheaval phenomena are common to happen. As a result, research on the influence ofcomplex contact between tire and road on structural responses of asphalt pavements isneeded, as well as add a new index for pavement structure design.Firstly, Tire three-dimensional FEM model was established. Because of thecomplex structure of the tires composed by kinds of rubber composite and cordmaterial, tire was reasonably simplified, two-dimensional numerical radial tire modelwas established based on ABAQUS code, and on the base of two-dimensional model,three-dimensional numerical model was obtained through rotation, reflectiontechniques.Secondly, large deformation and nonlinear tire contact with the rigid body modelwas set up. In the simulation of the contact between tire and deformable pavement, dueto both are deformable, it will be difficult to convergence. So based on the idea ofdecoupled, got the first step of calculation: establish tire contact with rigid road surfacemodel, analysis and extraction of the tire under static condition and free rolling tractionbraking conditions and the interaction between pavement stress field and its influencingfactors.Thirdly, got dynamic response of asphalt pavemen under non-uniform distributionof contact stress. based on the idea of decoupled, got the second step of calculation:stablish three-dimensional finite element model of semi-rigid base asphalt pavementbased on the viscoelastic characteristics of asphalt mixture; write DLOAD subroutinethough FORTRAN, non-uniform distributed stress between tire and rigid pavement isused as moving load when applied to viscoelasticity asphalt pavement structure,analysising dynamic response of asphalt pavement structure distribution in time andspace domain under free rolling and braking and traction. Finally, based on rutting, fatigue damage and load cracking diseases, analyzed thedangerous position with the corresponding key mechanical indicators respectively. Thecorresponding mechanics index for the asphalt pavement rutting disease is shear strainbetween the top layer and the middle layer; dangerous position of the fatigue damage isthe bottom of asphalt layer, and the corresponding mechanics index is Mises stress,tension and compression stress at the bottom of the semi-rigid base in horizontal andvertical direction are worthy of note. For load cracking, tensile strain and shear strain ofasphalt surface layer under the tire load should be focused on.