【作者】 郑仲浪；

【导师】 吕彭民；

【作者基本信息】 长安大学 ， 机械设计及理论， 2010， 博士

【摘要】 车辆是路面承受的主要载荷,而道路因长期承受车辆载荷而出现病害和破损。随着车辆向高速重载发展,车辆对道路的振动载荷不断增大,同时沥青混凝土路面由于材料选用、施工工艺等原因路面各层间无法达到完全连续状态,道路在重载车辆作用下的应力分布规律十分复杂,本文对重载车辆作用下沥青路面层间力学行为进行研究。在高速公路运行车辆车型、载重量、胎压等特点的调查基础上,建立了三轴车辆和四轴拖挂车辆半车振动模型。利用MATLAB软件在时域内仿真了三轴车辆和四轴拖挂车辆各轮的附加动载荷和动载系数。分析了路面等级、车辆行驶速度、车辆载重量、轮胎刚度和车辆结构参数对动载系数的影响。结合车辆动力学方程,建立了车辆上坡路段行驶速度预测模型。分析了路线坡度、坡长、车辆载重量及换挡速度的选择等因素对车辆行驶速度的影响。利用课题组相关人员开发的适合路面施工现场检测用的剪切仪,对路面结构层间粘结性能进行检测。得到了路面结构层间剪切强度及其变化规律。用连续、粘结两种状况模拟路面层间接触状态,并计算路面结构的应力分布规律。分析了路面结构层间不同接触状态下,路面各位置正应力、剪应力之间的分布规律和大小。层间接触状态为粘结状态时,路面结构表面的纵向拉应力和路面结构内部层间的横向拉应力值将增大。路面结构的纵向剪应力和横向剪应力的最大值出现的位置也不相同。利用路面层间接触模型分析了水平力、轮胎接地压力和温度等参数对路面结构动力响应的影响。水平力增加,轮胎接地压力的加大,会增大路面结构的弯沉、正应力和剪应力值。温度的升高,路面结构各位置的正应变和剪应变按非线性规律增大。路面是典型的粘弹性材料,可用Burgers模型模拟路面材料的粘弹特性。通过编写移动载荷子程序,建立了移动载荷作用下路面结构动态响应分析模型。分析了车辆速度对路面结构相应的影响。速度增大,各位置的正应力和剪应力值均减小。更多还原

【Abstract】 Vehicles are the main loads of the pavement, and the pavement is damaged due to the long-term effects of them. Because the vehicle’s velocities are higher and the loads of vehicles are heavier than before, the dynamic loads of vehicles are being increased. The interlayers of pavement can not be completely continuous due to different materials of pavement, road construction technology and other factors. So the stress variation in the pavement is complex. The interfacial mechanical behavior of asphalt pavement under heavy vehicle loading is studied in the paper.A 3-axle vehicle vehicle model and a 4-axle vehicle model are established base on the character of the vehicle travel on the highway. The additional dynamic load and dynamic load coefficent of the 3-axle vehicle and the 4-axle vehicle are simulated with MATLAB. The effects of road parameters, vehicle velocity and mechanism parameters of vehicles on the dynamic load coefficent are studied. A vehicle speed prediction model on the uphill section is established base on the vehicle dynamics equation. The influences of the slope, slope length, vehicle load and the choice of shifting speed are studied.The bond behavior of the interlayer is tested with the shear device designed by the research group. The shear strength and its variation of the interlayer are obtained.The contact status of the interlayer are simulated as continuous or bond, and the dynamic responses are calculated. The normal stress and shear stress in the pavement are studied under the different contact conditions. When the interlayer is bond, the longitudinal and transverse normal stresses of the pavement are increased, and the positions of the maximum of longitudinal and transverse shear stress in the pavement are changed.The influences of the horizontal force, tire contact pressure and temperature are studied. The normal stress and the shear stress in the pavement are increased when the horizontal force and the tire contact pressure are increased. The normal strain and the shear stress are increased with the temperature.The asphalt is a typical viscoelastic material. The Burgers model is used to simulate the properties of it. A pavement structure model under moving load for dynamic response analysis is established through the moving load subroutine. The influence of vehicle speed is analysised. The normal stress and the shear stress in the pavement are decreased when vehicle speed is increased.更多还原