避险车道制动床上失控车辆车轮沉陷深度研究

Research on Tire Subsidence Depth of Runaway Truck on Truck Escape Ramp

避险车道制动床上失控车辆车轮沉陷深度是制动床铺设厚度设计的主要理论依据。为此,建立悬架-车轮-集料三维离散元模型并开展车轮沉陷深度数值模拟。首先在PFC3D中利用Fish语言建立悬架-车轮-集料三维离散元模型;其次通过静力三轴压缩试验标定集料离散元颗粒参数;通过实车足尺试验数据标定车轮离散元颗粒参数;最后利用标定的模型分别模拟不同砾石粒径、驶入初速度、载重对车轮沉陷深度的影响。结果发现:三维模型比二维模型更能准确描述车轮沉陷深度。在粒径推荐范围内,砾石粒径越小,车轮沉陷深度越大;车轮载重越大,车轮沉陷深度越大;驶入初速越小,车轮沉陷深度越大;车轮沉陷深度越大,减速效果越好。

The tire subsidence depth of runaway truck on truck escape is the main theoretical basis for the design of the thickness of the arrester bed. To this end,a three-dimensional discrete element model of suspension-tire-aggregate was established,and the numerical simulation of the tire subsidence depth was carried out. Firstly,the three-dimensional discrete element model of suspension-tire-aggregate was established by using the Fish language in PFC3 D software. Secondly,the aggregate discrete element micro-parameters were calibrated by static tri-axial compression test and the tire discrete element micro-parameters were calibrated by the actual vehicle test. Finally,the numerical simulation was carried out by using the calibrated model: the influence of gravel particle size,initial velocity and load on the tire subsidence depth law was studied. It is found that the established three-dimensional discrete element model can accurately describe the tire subsidence law more than the tire-aggregate three-dimensional discrete element model. Within the recommended range of particle size,the smaller the gravel particle size,the bigger the tire subsidence depth;the larger the tire load,the bigger the tire subsidence depth;the smaller the initial speed,the bigger subsidence depth of the tire;the bigger the tire subsidence depth,the better deceleration effect.