Abstract: Bridge and vehicle are treated as two separate systems.1/2 four free degree vehicle model is proposed;their dynamic equations are established with the adoption of virtual work theory.According to the power spectral density function advised by GB/T 7031-1986,different values of different bridge deck roughness are obtained.The time-domain response of the simply-supported beam in different bridge deck roughness caused by moving vehicle is obtained by numerical simulation,and the variety rule of impacting factor is also obtained.The result shows that the value of impacting factor increases along with vehicle velocity but not linearly along with the grade of highway bridge deck roughness.The grade of bridge deck roughness is the most remarkable factor influencing vehicle dynamic effect.

Key words: bridge deck roughness, vehicle-bridge couple vibrations, impacting factor, dynamic response

摘要： 把桥梁和车辆看作两个分离体系,提出了四自由度1/2车辆模型;应用广义虚功原理建立振动方程,并引用国标(GB/T 7031-1986)建议的公路路面功率谱密度的拟合表达式,求得了不同等级桥面的不平整度值;通过数值仿真得到不平整桥面简支桥梁在运行车辆作用下的时域响应,获得了相应冲击系数随桥面等级及车速变化规律。结果表明,桥梁冲击系数随着车速增加呈增大趋势;随着公路桥面等级变差呈非线性增大,桥面等级是影响车辆动力作用的最显著因素。

关键词: 桥面不平度, 车-桥耦合, 冲击系数, 动力响应