长陡坡路段车辆额定功率下的运动特性分析

Analysis of operational characteristics of heavy vehicle under rated power condition on long and steep section of mountainous highway

在选定山区高等级公路长陡坡路段标准车型的基础上,文章提出了一个简单的汽车动力学模型用以预测该路段重载车辆最大加速度水平下的运动状态和对路面的水平剪切作用;在Virginia Tech Transportation Institute(VTTI)的Smart Road试验路上的现场检测数据验证了上述动力学模型的正确性;给出了不同坡度、初速度条件下的速度-水平距离和水平剪切力-水平距离关系曲线;提出了平衡速度的概念和求解方法。研究结果表明标准车的初速度对水平剪切力的影响较小,而纵坡对水平剪切力的影响较大。

This paper presents a simple vehicle dynamic model for：estimating maximum acceleration and speed levels and horizontal shear stress on the pavement based on the selection of standard model of vehicles on long and steep section of mountainous high-grade highway. The accuracy of the above vehicle dynamic model is calibrated against field data collected along the Smart Road test facility at Virginia Tech Transportation Insti- tute（VTTI） by utilizing a semi-trailer. The results show the relationships between velocity and horizontal dis- tance and between horizontal shear stress and horizontal distance under different longitudinal grades and initial velocities. The concept of equilibrium speed and its solution method are proposed. It is shown that the initial velocity of standard model of vehicle has little effect on horizontal shear stress, but the longitudinal grade has very important impact on horizontal shear stress.