虚拟轨道列车作用下黏弹性路面响应及变形分析

Dynamic Response and Permanent Deformation Analysis of Asphalt Pavement under the Virtual Rail Train

虚拟轨道列车作为一种新兴的交通工具,充分发挥了公路运输适应性强和轨道列车运输量大的特点,经调研发现该车运行线路已产生严重的永久变形。采用解耦的方式将轮胎与刚性路面相互作用模型的三向接触力提取并施加到黏弹性沥青有限元模型,针对虚拟轨道列车轮胎在匀速、完全制动及转弯3种行驶工况下沥青路面的动力学响应及永久变形进行分析研究。研究结果表明,路表剪应力和永久变形在匀速行驶时均随速度的增加而减小,其中,运行速度为20km·h^-1的路表剪应力较60km·h^-1的分别增大65%(纵向范围)、54%(横向范围);20km·h^-1较60km·h^-1的纵向、横向和垂向永久变形均增大50%左右。在纵向范围内完全制动比匀速行驶的路表最大剪应力增大66%,沿道路深度方向增大76%。纵向永久变形在完全制动时较匀速行驶时分别增大93%(10.512万次)、99%(52.560万次)、100%(105.120万次)。垂向永久变形在转弯时沿着轮胎转弯内侧累积。完全制动的剪应力最大值相较于匀速时下移0.01m。因此,从控制路面剪应力及永久变形的角度,列车运行速度越高越有利于减缓路面损坏;在列车制动/启动及转弯位置要提高沥青混合料抗剪强度来预防沥青路面沿纵向和横向的累积变形。

As a new type of transportation,virtual rail train has brought into full play the characteristics of strong adaptability of road transportation and large capacity of rail train.It is found that the running line of the virtual rail train has produced serious permanent deformation.Therefore,this paper uses a decoupling method to extract the three-way contact force of the tirerigid road interaction model and act on the viscoelastic asphalt finite element model,aiming at the virtual track train tires in the three driving states of constant speed,full braking and steering The dynamic response and permanent deformation of asphalt pavement are analyzed and studied.The research results show that the road surface shear force and permanent deformation both decrease with the increase of speed when driving at a constant speed.Among them,the road surface shear force at a running speed of 20 km·h^-1 increases by 65%respectively compared with that of 60 km·h^-1(longitudinal range),54%(transverse range);the permanent deformation of 20 km·h^-1 is about50%larger than that of 60 km·h^-1.In the longitudinal range,the maximum shear force of full braking is 66%higher than that of the road surface driving at a constant speed,and 76%is increased along the road depth.Longitudinal permanent deformation increases by 93%(10.512 million times),99%(552.56 million times),and 100%(105.12 million times)respectively when fully braking compared to when driving at a constant speed.The maximum road surface shear force and the maximum horizontal and vertical permanent deformation are located on the inner side of the steering when turning.The maximum value of shear force under constant speed driving,full braking,and turning is on the upper layer.The maximum value of constant speed driving and turning is 0.03 m from the road surface,and the maximum value of full braking is 0.04 m away from the road surface.From the perspective of controlling road shear and permanent deformation,the higher the train running speed,the better it is to reduce road damage.