基于离散单元法的沥青马蹄脂模型细观参数确定

摘要

采用离散元软件PFC对沥青马蹄脂的细观力学行为进行模拟,其中数值模型细观参数的确定是国内外研究学者公认的难题.为了解决这一难题,PFC程序采用伯格斯粘弹性模型模拟沥青马蹄脂的细观接触,并通过伯格斯模型本构行为方程推导模型参数与细观参数之间关系,然后通过室内试验将代表材料性质的宏观参数转化成细观参数,并给出具体的表达式,避免使用模型参数试算的方法,从而直接确定PFC接触模型参数.%Microscale mechanical behavior of asphalt mastic is simulated according to discrete element software PFC( particle flow code) ,and how to determine microscale parameters of numerical model is recognized as a hard nut to crack at home and abroad. In order to solve the problem, microscale contact behavior of asphalt mastic is simulated by using Burger' s viscoelastic model in particle flow code. At the same time, the relation between model parameters and microscale parameters is derived from the constitutive behavioral equation of Burger' s model, and then, Macroscale parameters representing material property by experiment are converted to microscale parameters in model. Furthermore, concrete expressions are given, and using tentative calculation method to determine model parameters is avoided, therefore, model parameters at a contact are directly confirmed.