考虑车轮-路面接触长度的桥头跳车动力荷载分析

对车辆经过桥头错台时的动力荷载进行分析，提出考虑轮胎-路面接触长度的车轮模型，并计及车轮的滚动轨迹。结合有限元动力学分析方法，对车辆上、下桥头错台时的动力荷载进行定量分析。数值仿真表明：考虑接触长度的模型更符合车轮与路面接触的实际情况，动力荷载计算值较平缓；下桥跳车时车轮脱空的临界速度计算值大大提高，10 mm错台跳车临界速度约60 km/h；跳车动力荷载与车轮悬挂方式、车速、跳车高度等有关，可由此控制轮载冲击系数；考虑车轮-路面接触长度后，桥头错台跳车的冲击系数仍较大。车辆以30 km/h以上速度通过10 mm错台时，冲击系数超过我国桥梁规范设计值，需引起重视。

The numerical analysis of dynamic load in bridge-head bumping considering the contact length between the tire and the road

To analyze the dynamic load of vehicle in bridge-head bumping, a tire model considering the contact length between the tire and the road is presented, where the rolling trace of the tire is also taken into account. Combined with the finite element dynamic analysis, the load of the tire when the vehicle passes through the staggered platform at bridge head is analyzed quantitatively. Numerical examples show that (1) the model is more accords with actual contact phenomena between the tire and road, and calculated dynamic load is less than before; (2) the calculated critical speed when the vehicle getting down the staggered platform is much higher than before, for example, it is about 60 km/h when the vehicle gets down the 10mm-high platform; (3) the dynamic load is related with suspension pattern, speed of vehicle and height of the platform, the impact factor could be controlled; (4) the impact factor is still high when the contact length is considered, for example, it is more than 0.3 when the vehicle passes through a staggered platform of 10 mm with the speed of 30 km/h, which is higher than that provide by Chinese design codes of bridge, it is worthy of our reference.