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为了研究法国高模量沥青混凝土疲劳性能及Burger’s模型参数与疲劳寿命之间的关系,在离散元软件PFC3D中建立了沥青混凝土锥棱柱两点疲劳弯曲试验的虚拟模型.计算了虚拟试件的初始刚度及达到疲劳时的最大接触应力,并与实测单次疲劳试验曲线对比,验证了用DEM模拟疲劳试验的可行性.然后研究端部位移及Burger’s模型中各项参数(E_1,E_2,η_1,η_2)对疲劳寿命的影响.数值模拟结果表明,随着端部控制位移增大,到达疲劳时最大应力增大.研究证实:随着沥青砂浆Burger’s模型参数中E_1增大,E_2减小,沥青模量增大,沥青混合料的疲劳寿命得到有效提升;η_1和η_2对疲劳寿命的影响较小.
In order to study the fatigue behavior of French high modulus asphalt concrete and the relationship between Burger’s model parameters and fatigue life, a virtual model of two-point fatigue bending test of asphalt concrete pyramid was established in discrete element software PFC3D. Stiffness and the maximum contact stress at the time of fatigue were obtained, and compared with the measured single fatigue test curve to verify the feasibility of using DEM to simulate the fatigue test.Finally, the displacement of the tip and Burger’s model parameters (E 1, E 2, η 1, η_2) on the fatigue life.The results of numerical simulation show that the maximum stress reaches to fatigue when the end control displacement increases, and the results show that with the increase of E_1 and the decrease of E_2 in asphalt mortar Burger’s model parameters, As the modulus increases, the fatigue life of asphalt mixture can be effectively improved. The influence of η_1 and η_2 on the fatigue life is small.