Research On Fatigue Damage Of Highway Asphalt Pavement Based On Mixed Lagrange-Euler Algorithm

The highway develops with each passing day in china, the combined effects among highway, high flow and highly channelizing traffic decrease the self-repaired role of asphalt pavement of highway, which result in an earlier damage and the overload transport also aggravates the damage of pavement. The fatigue failure has become one of a main form of asphalt pavement failure of highway. However, due to the highly nonlinear of the tire structure and material, and the influence factors, such as tire inflation pressure, rotation speed, axle load and rolling-sliding relation between tire and pavement, the values and distribution of contact stress are extremely complex and affect the tensile stress and tensile strain of pavement, as well as affect wear, deformation and fatigue life of pavement. Therefore, it is necessary to establish tire-subgrade-pavement 3D coupling model to discuss the influence factors of fatigue life of asphalt pavement of highway. The main contents are summarized as below:1) Based on experiments of silt, a comprehensive evaluation on prediction of the stress-dependent dynamic resilient modulus of subgrade soil is performed and a revised dynamic resilient modulus model with four parameters is proposed. The revised model is also implemented into finite element code ABAQUS by compiling the user material subroutine and is used to simulate successfully the deformation of asphalt pavement and subgrade structure.2) The 3D finite element model of tire-subgrade-pavement structure is established. The stable rolling of tire and stress-dependent dynamic resilient modulus of subgrade soil are considered in the model. The different loading modes, such as simplified wheel load and direct wheel load, are adopted to calculate the static responses of subgrade-pavement structure and discuss the influence of loading modes on stress-strain responses located in contact zone between pavement and tire.3) The stable transport analysis method is adopted to calculate the stable responses of wheel with different rolling states, the influences of wheel drag, friction coefficient, axle load and tire pressure on stress-strain response of pavement in the initial free rolling state of tire.4) The mechanism of fatigue cracking of asphalt pavement is indicated by the fatigue life prediction model, the influences of wheel drag, friction coefficient, axle load and tire pressure on fatigue lives are discussed based on the tensile strain fatigue prediction model.