基于内聚力模型的沥青混凝土疲劳损伤数值研究(英文)

Numerical study of fatigue damage of asphalt concrete using cohesive zone model

为了研究沥青混凝土的疲劳特性,提出了基于双线性内聚力模型(CZM)的数值模拟方法.建立了疲劳损伤演化模型并将其与内聚力模型耦合,以反映沥青混凝土在循环荷载作用下的软化行为.通过编制用户材料子程序,实现了疲劳损伤模型在有限元软件ABAQUS中的应用,并对劈裂疲劳试验进行了模拟.研究结果表明:模拟得到的疲劳寿命与实验室结果基本一致;疲劳损伤随加载次数的累积是非线性的,且损伤累积阶段是疲劳破坏的主要阶段;应力比增大时,损伤稳态发展阶段的寿命明显减小.可以发现提出的疲劳损伤数值模型是一种预估沥青混凝土疲劳损伤的有效方法.

In order to investigate the fatigue behavior of asphalt concrete, a new numerical approach based on a bi-linear cohesive zone model （CZM） is developed. Integrated with the CZM, a fatigue damage evolution model is established to indicate the gradual degradation of cohesive properties of asphalt concrete under cyclic loading. Then the model is implemented in the finite element software ABAQUS through a user-defined subroutine. Based on the proposed model, an indirect tensile fatigue test is finally simulated. The fatigue lives obtained through numerical analysis show good agreement with laboratory results. Fatigue damage accumulates in a nonlinear manner during the cyclic loading process and damage initiation phase is the major part of fatigue failure. As the stress ratio increases, the time of the steady damage growth stage decreases significantly. It is found that the proposed fatigue damage evolution model can serve as an accurate and efficient tool for the prediction of fatigue damage of asphalt concrete.