A part of the multilayer pavement structure containing top‐down crack in the hot mix asphalt (HMA) layer and subjected to loading of a moving vehicle is simulated using the finite element method. Aggregate distribution and packing algorithm was used for modeling the HMA layer around the top‐down crack as a heterogeneous two‐phase (aggregate/fine aggregate matrix [FAM]) medium. By considering the heterogeneity aspects of the asphalt mixture, the influence of traffic loading location, aggregate distribution, crack length, thickness layer, and mechanical properties of layers and components were investigated on the fracture parameters. The results showed that for different locations of vehicle wheels relative to the top‐down crack, the magnitude and sign of the fracture parameters in heterogeneous modeling were significantly different from the similar values of the homogeneous simulation. The stress intensity factors and especially the T‐stress were significantly sensitive to the crack tip location that can be placed either inside the stiffer aggregate or the softer FAM part.

中文翻译：

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非均质性对自上而下裂纹并承受交通荷载的多层沥青路面结构断裂参数的影响

使用有限元方法模拟了多层路面结构的一部分，该结构在热混合沥青（HMA）层中具有自上而下的裂缝并承受了行驶车辆的载荷。骨料分布和填充算法用于将自上而下的裂缝周围的HMA层建模为异质两相（骨料/细骨料矩阵[FAM]）介质。考虑到沥青混合料的非均质性，研究了交通荷载位置，集料分布，裂缝长度，厚度层以及层和组分的力学性能对断裂参数的影响。结果表明，对于车轮相对于自上而下裂纹的不同位置，均质模拟中裂缝参数的大小和符号与均质模拟的相似值明显不同。应力强度因子，尤其是应力强度因子T应力对裂纹尖端的位置非常敏感，裂纹尖端的位置既可以放置在较硬的骨料中，也可以放置在较软的FAM零件中。