基于数字图像与颗粒流程序的沥青混合料单边切口梁试验  

Single-Edged Beam Test of Asphalt Mixture Based on Digital Image and Particle Flow Code

作　　者：顾永明 王江洋 

机构地区：[1]苏州交投规划设计建设管理有限公司,江苏苏州215007 [2]东南大学智能运输系统研究中心,江苏南京210018

出　　处：《现代交通技术》2017年第5期1-5,共5页Modern Transportation Technology

基　　金：国家自然科学基金项目(项目编号:51178114;51408125)

摘　　要：为了在细观尺度下模拟沥青混合料的断裂过程,借助数字图像技术获取了1.18 mm粒径以上的沥青混合料细观结构,运用离散元程序PFC2D内置"Fish"语言,构建了包含粗骨料、沥青胶浆和空隙在内的沥青混合料非均质虚拟试件,对虚拟试件微观组成成分之间的接触赋予了相应的微观接触模型,采用离散元方法实施了单边切口小梁虚拟3点弯曲试验。研究结果表明:自定义时步大小功能可以大幅提高非均质离散元模型的运算效率;采用沥青胶浆动态模量作为静态模拟时接触刚度所对应宏观参数更为合适;参数校准后模拟得到的整体断裂响应与室内试验结果之间的联系较好;仅采用试件单面图像信息构建模型进行力学性能预测缺乏可信度;基于离散元程序的虚拟试验方法可以作为研究沥青混合料断裂行为的辅助手段。In order to simulate the fracture process of asphalt mixture under the micro-scale perspective, the microstructure with coarse aggregates larger than 1.18 mm was captured using the digital image processing frirstly. Secondly, a heterogeneous virtual specimen of asphalt mixture including coarse aggregates, asphalt mastic and air voids was reconstructed using the Fish language provided in the discrete element software PFC2D.The corresponding micromechanical models describing the interaction of microscale components of the virtual specimen were assigned. Finally, a single-edge notched beam virtual three-point bending test was implemented using the discrete element method（DEM）. The results indicated that the technique so-called user-defined timestep is employed to significantly improve the computational efficiency for heterogeneous discrete element simulations. Additionally, the dynamic modulus of asphalt mastic used as the macro parameter corresponding to the contact stiffness is more reasonable than the static modulus. Moreover, the macro fracture response of virtual test show generally good agreement with the experimental results based on the inverse analysis of the material parameters. However, the model reconstructed using the digital image from the single face of the specimen is short of credibility. Furthermore, it is found that the virtual test method based on the DEM program can be used as a supplemental tool to investigate the fracture behavior of asphalt mixture.

关 键 词：沥青混合料 数字图像处理 非均质虚拟试件 离散元方法 虚拟断裂试验 

分 类 号：U416.21[交通运输工程—道路与铁道工程]