基于非线性疲劳损伤特性的沥青路面形变规律

Deformation Regularity of Asphalt Pavement Based on Nonlinear Fatigue Damage Characteristics

为了研究沥青路面结构在车辆荷载作用下的疲劳损伤演化特性,并分析其形变规律,运用通用有限元软件ABAQUS及其二次开发平台,建立考虑路面材料非线性疲劳损伤的沥青路面结构数值计算模型,分析沥青路面结构在车辆荷载反复作用下路面结构损伤和路面结构水平正应变的空间分布及演化规律,以及路表弯沉随荷载作用的演变规律。结果表明:路面结构损伤主要分布在双轮中心线下靠近层底的区域,基层层底与底基层层底损伤度随荷载作用均增加,且增加幅度逐渐增大;靠近层底位置拉应变逐渐增大,且增加幅度逐渐增大,中性轴上移;路表弯沉在荷载作用下逐渐增大,增大幅度逐渐增大,其规律与相关实测结果相符。研究结果可为沥青路面结构设计、养护维修及长期性能预测提供理论支撑。

In order to study the fatigue damage characteristic and deformation regularity of asphalt pavement under vehicle load, by using the general finite element software ABAQUS and the secondary development platform, an asphalt pavement numerical model which considers pavement material nonlinear fatigue damage was established to analyze the spatial distribution/evolution of asphalt pavement structure damages, the spatial distribution/evolution of asphalt pavement structure horizontal normal strains, and the evolution of pavement surface deflection varying with loads under repeated vehicle load. The results show that （ 1 ） The pavement structural damage mainly distributes in a specific damage zone located at the bottom of the layer along the middle line between the double wheels. With the increasing of load cycles, the damage degrees at the bottom of the base layer and the sub-base layer increase, and the rate of which gradually increases. （2） The horizontal tensile strain close to the bottom of the pavement layer increases, the rate of which gradually increases, and neutral axis moves upward. （3） The deflection of pavement surface increases with the increase of load cycles, and the rate of which increases gradually. The regularity is in agreement with related measured results. The results can provide a theoretical support for asphalt pavement structure design, maintenance and prediction of the long-term performance.