交通荷载作用下沥青路面裂缝尖端的应力强度因子分析

考虑沥青混合料粘弹性断裂力学行为,对于沥青路面的开裂或反射性裂缝的扩展行为研究具有重要意义.基于粘弹性断裂理论,采用非线性有限元软件ABAQUS,分析交通动荷载作用下不同车速、不同基层模量对含有裂缝路面结构体系的位移场和应力场的影响.计算结果表明:裂缝尖端应力强度因子变化曲线随着车速的增加发生移动,且峰值几乎不变;随着基层模量的增加,应力强度因子增大.在偏荷载作用下裂缝尖端应力强度因子由KⅠ、KⅡ组成,当基层模量较小时裂缝尖端应力强度因子主要表现为KⅡ,随着弹性模量的增加KⅠ增大,KⅡ几乎保持不变.

Analysis of stress intensity factor at crack tip on asphalt pavement under action of traffic load

Consideration of viscoelastic fracture mechanical behavior of asphalt mixture has a profound meaning to investigate the behavior of crack initiation on asphalt pavement or the behavior of radiant crack propagation.Based on the viscoelastic fracture theory and by using the nonlinear finite element software ABAQUS,the influences of different car speeds and different base course modulus on the displacement field and stress field in the pavement structural system with cracks was analyzed for the case of dynamic traffic load.The computation result indicated that the variation curve of the crack tip stress intensity factor was shifted with the increase of car velocity and its peak value was almost unchanged.The stress intensity factor was increased with the increase of base course modulus.Under the action of biased load,the crack tip stress intensity factor was comprised of KⅠ and KⅡ.When the base course modulus were relatively small,the stress intensity factor was mainly represented by KⅡ.The KⅠ would increase with the elastic modulus and the KⅡ remain almost unchanged.