基于X-ray CT技术和有限元方法的沥青混合料剪应力计算分析

Calculation and Analysis of Shear Stress of Asphalt Mixture Based on X-ray CT Technology and Finite Element Method

为了从三维细观角度进行沥青混合料的剪应力计算分析,应用nano-CT设备扫描获得的芯样图像及Simpleware图像处理软件,结合有限元方法,建立了与混合料内部实际空间分布一致的三维数值模型,同时考虑温度的变化分别赋予集料、胶浆及空隙以相应材料参数,进行最大剪应力值的计算。结果表明:三维数值试样内部的剪应力分布呈现不均匀性,大部分剪应力由集料承担;最大剪应力值随着温度的升高而增大,表明混合料在高温条件下更易发生剪切破坏,而宏观抗剪强度的测定验证了计算结果的合理性。

In order to calculate and analyze shear stress of asphalt mixture based on three-dimensional microscale,three dimensional numerical model consistent with the actual spatial distribution of mixture was established by using core images of nano-CT scanning and Simpleware image processing software combined with finite element method,aggregate,mortar and void were given corresponding material parameters considering the change of temperature,and the maximum shear stress value were calculated.The results show that the shear stress distribution is not uniform within the three-dimensional numerical samples,most of the shear stress borne by the aggregate;the maximum shear stress value increases with the increase of temperature,which indicates that shear failure occurs more easily under high temperature conditions,and the rationality of the calculation results was verified by the macro-shear strength determination of mixture.