基于车-桥耦合振动理论的连续梁桥影响因素分析

Analysis of influences of different factors on continuous rigid frame bridges based on theory of vehicle-bridge system coupling vibration

通过研究车辆模型及桥梁模型,基于接触点位移协调条件,建立车-桥系统耦合振动运动方程组。用有限元软件MIDAS/CIVIL分析不同影响因素下桥梁的动力特性,揭示桥梁跨中竖向位移、弯矩冲击系数、竖向加速度等指标的变化规律。根据有限元分析结果,编译车-桥耦合振动系统影响因素分析程序,研究各因素对桥梁动力特性的影响。研究结果表明:车辆速度、行车数和桥面不平整度都对桥梁的动力特性有一定程度的影响;车辆速度对跨中竖向位移的影响最大,桥面不平度对跨中竖向加速度的影响最大,跨中弯矩冲击系数受车辆速度的影响最大。最后通过正交试验验证该程序分析结果的可靠性。

Based on analysis for the bridge and vehicle models, the motional equation sets of vehicle-bridge system coupled with vibration were set up considering the condition of the displacement compatibility at the contact point of wheel and bridge panel. The MIDAS/CIVIL software was used for analyzing the dynamic properties of the bridge under different conditions. The results show that the influences of different factors on the main bridge indices, e.g. the vertical displacement, impact coefficient of moment, and vertical acceleration at the mid-span of bridge, etc. Then the vibration-coupled vehicle-bridge system program that can analyze the factors on the main bridge indices was compiled.And this program was employed to analyze the dynamic properties of bridge. The results show that the vehicle speed, the number of vehicle, and the surface roughness of bridge have influences on the dynamic properties of bridge. The vehicle speed and the surface roughness of bridge play the key roles on the vertical displacement and vertical acceleration at the mid-span respectively. The vehicle speed also has a maximum influence in the impact coefficient of moment at the mid-span. Moreover, the reliability of this program is validated by the orthogonal experiment.