摘要
In this paper, a four-layered road structure containing a top-down crack is investigated by performing finite element analyses in ABAQUS. In this study, in addition to the vertical load of a vehicle wheel, the horizontal load as well as its position with respect to the crack is also considered in the analyses, and the crack tip parameters including stress intensity factors(SIFs) and T-stress are then calculated. Moreover, influence of elastic modulus and thickness of the pavement layers on the crack tip parameters is studied. Results show that the horizontal and vertical loads along with their position with respect to the crack, elastic modulus and thickness of the road layers influence the crack tip parameters(KⅠ, KⅡ and T-stress) significantly. It was also found that for the cases that the vehicle wheel is positioned near the crack plane, only the shear deformation mode is observed at the crack tip;while, for the vehicle wheel positions far from the crack, only the opening mode is observed, and between these positions, both the opening and shear deformation modes(i.e., mixed mode Ⅰ/Ⅱ) are observed at the crack tip.
采用有限元分析方法,研究了一种具有自顶向下裂缝的四层道路结构。在本研究中,除了考虑车辆车轮的垂直荷载外,还考虑了车轮的水平荷载及其相对于裂纹的位置,进而计算了包括应力强度因子(SIFs)和T-应力在内的裂纹尖端参数。此外,还研究了弹性模量和铺装层厚度对裂纹尖端参数的影响。结果表明,水平荷载和竖向荷载及其相对于裂缝的位置、路面层的弹性模量和厚度对裂缝尖端参数(KⅠ、KⅡ和T-应力)有显著影响。研究还发现,当车轮定位在裂纹面附近时,裂纹尖端处只有剪切变形模式;而对于远离裂纹的车轮位置,只观察到裂纹的张开模式,在这些位置之间,在裂纹尖端同时观察到张开和剪切变形模式(即混合模式Ⅰ/Ⅱ)。
