车路相互作用下沥青路面材料弯曲破坏研究

为分析车辆荷载作用下沥青路面面层底部材料产生的弯拉破坏,构建了路面与二自由度1/4车辆的离散元相互作用模型,以计算在路面不平顺激励下的车路相互作用力和路面沥青材料的宏细观动态响应.另外,选取面层沥青材料进行弯曲破坏试验,得到了沥青材料在加载过程中裂缝产生和开裂时的应变场分布.在此基础上,应用PFC2D软件构建沥青材料离散元模型来模拟其加载破坏过程,以探究车路相互作用下沥青面层的弯曲细观破坏机理.研究发现:弹性阶段后,沥青材料内部开始出现微裂纹,随着车辆荷载增加,材料最薄弱区域的微裂纹汇集成宏观裂纹直至破坏;在一定数值范围内,沥青材料空隙率对其抗开裂性能影响较大.试验结果证实了数值模拟的准确性.

Bending Failure of Asphalt Pavement Materials under Vehicle Road Interaction

The bending damage of asphalt pavement bottom material under vehicle load was analyzed and the interaction discrete element model(DEM) of pavement and two degree of freedom quarter vehicle was constructed. The vehicle road interaction force under road irregular excitation was calculated and DEM model was used to calculate the dynamic response of asphalt pavement material at macro and micro scales. Bending failure experiments of surface asphalt material were carried out, and the strain field distribution of crack generation during asphalt loading was measured. The discrete element model of asphalt material was constructed by PFC2D, and the loading and failure process was simulated. The bending mesoscopic damage of the asphalt surface layer under the interaction of the vehicle and road was explored. It was found that after the elastic stage, micro cracks begin to appear in the asphalt material. As the vehicle load increase, the macro cracks converge in the weakest area of the material until failure. The numerical simulation was consistent with the experimental change trend. Results show that the voidage has a great influence on the cracking resistance of asphalt materials in a certain range of values.