汽车行驶诱发地表振动的解析研究

本文从汽车动力学出发,建立 1/4 汽车与半空间地基耦合振动的动力学模型,并采用弹性滚子接触模型来反映轮胎包容性. 模型中同时考虑轮-地之间的纵向和竖向作用力,构建系统动力控制方程,利用 Fourier 和 Laplace 积分变换进行求解,推导出地表振动位移的解析解. 在数值算例中,利用离散傅里叶逆变换和 Crump 法进行数值反演,得出地表振动位移的空间分布,由此讨论了轮胎着地长度和轮-地相互作用力的变化规律,并对地表振动位移的参数影响作出分析. 结果表明,地面不平度对轮-地之间作用力的影响最为显著,地面越不平顺则轮-地作用力和地表振动位移越大. 车速对轮-地作用力的大小影响有限,但对载荷激励频率影响较大,车速增大则激励频率增大,地表振动位移随之增大. 在较低车速时,轮胎包容性对轮-地作用力和地表振动产生一定影响,轮胎充气压力增大,轮-地作用力和地表振动位移增大,但随着车速升高,这种影响将逐渐消失. 

ANALYTICAL STUDY ON GROUND VIBRATION INDUCED BY MOVING VEHICLE

Based on vehicle dynamics, the coupling vibration model between vehicle and ground is established, and the contact model of elastic roller is adopted to reflect the tyre tolerance. At the same time, the longitudinal and vertical forces between the wheel and the ground are considered, the system dynamic control equation is constructed, and the analytical solution of the surface vibration displacement is obtained by using Fourier and Laplace integral transformation. In the numerical example, the inverse discrete Fourier transform and Crump's method are used to do the numerical inversion, and the time domain solution of the surface vibration displacement is obtained, the influence of the parameters of the surface vibration displacement is analyzed. The results show that the surface irregularity has the most significant influence on the wheel-earth interaction, and the more uneven the ground, the greater the wheel-earth interaction and the greater the surface vibration displacement. The influence of vehicle speed on the wheel-ground force is limited, but it has a great influence on the excitation frequency of load. When vehicle speed increases, the excitation frequency increases, and the surface vibration displacement increases accordingly. At a low speed, tire inclusivity has a certain effect on the wheel-ground force and surface vibration. With the increase of tire inflation pressure, the wheel-ground force and surface vibration displacement increase, but with the increase of speed, this effect will gradually disappear.