Predicting Fatigue Damage of Asphalt Concrete Using a Cohesive Zone Model.

This paper describes a bi-linear cohesive zone model to simulate fatigue behavior of asphalt concrete. To demonstrate the gradual degradation of cohesive properties of asphalt concrete under cyclic loading, a fatigue damage evolution law was integrated into the cohesive zone model. The model was then implemented in commercial finite element software ABAQUS using a user-defined subroutine. A damage extrapolation scheme was adopted to reduce computational cost for high-cycle fatigue applications. Based on the proposed model, a flexural beam fatigue test was finally simulated. The fatigue lives and other features of damage evolution obtained through numerical analysis are in consistence with experimental data, which indicates that the proposed cohesive zone model could be applied to predict fatigue damage of asphalt concrete with good accuracy. During the fatigue loading process, stiffness decreases linearly while damage accumulates non-linearly and grows faster with the increase of fatigue damage. The duration of crack propagation stage is much shorter than the damage initiation stage. The tensile stress at the crack tip increases with the propagation of fatigue crack. [ABSTRACT FROM AUTHOR]