车、路的相互作用下沥青路面动力学特性分析

Dynamical analysis of an asphalt pavement due to vehicle-road interaction

采用二自由度四分之一汽车悬架模型模拟汽车系统,依据弹性层状体系理论,建立路面结构的三维有限元分析模型,考虑车路相互作用,采用ANSYS有限元分析软件对移动车辆荷载作用下路面各结构层中的位移、应力、应变进行了模拟。计算分析了行车速度、悬架刚度、悬架阻尼、轮胎刚度和轮胎阻尼五个参数对路面动力响应的影响。结果表明:沥青面层处于三向受压状态,层内切应力是引起其破坏的主要原因;最大水平拉应力和最大横向拉应力均发生在路面结构的基层和底基层结合处;车速对路面动态响应的影响规律很复杂,应考虑车辆模型和路面不平整度,并划分速度区间加以探讨;路面动态响应随轮胎刚度、悬架刚度和悬架阻尼的增大而减小。上述结论对于深入分析路面结构动力响应与疲劳损坏以及研究车辆与路面相互作用的机理有重要价值。

A three-dimensional vehicle-road-foundation interference system was modeled. A moving vehicle was simplified as a 'quarter-vehicle' model. A 3-D model of an asphalt pavement was established based on the elastic layered theory. The time-dependent deflection and the stress of the asphalt pavement were obtained by linking the characteristics of a road profile, a moving vehicle, and a multiple layered pavement structure together. A detailed model parametric study then followed to show the effect of vehicle velocity, suspension stiffness, suspension damping, tire stiffness, and tire damping on the road dynamic response. The study was conducted with ANSYS program. The results showed that under the three-dimensional pressure, the failure of the asphalt concrete was mainly caused by shear stress; the maximum horizontal tensile stress and the maximum transverse tensile stress all existed in the joint region of the base and the subbase course; the influence of the vehicle speed on the pavement dynamic responses was complicated, it should be further discussed considering road profile and vehicle model; the pavement dynamic responses decreased with increase in suspension stiffness, suspension damping, and tire stiffness .These conclusions may be useful for further analysis of dynamic responses and damages of a road structure as well as interaction between vehicle and road.