弹性支承下大跨连续梁桥车桥耦合振动响应分析

Vehicle-Bridge Coupling Vibration Response Analysis of Long-Span Continuous Girder Bridge with Elastic Support

为探讨弹性支承下梁桥车桥耦合振动响应,用弹簧-阻尼单元模拟支座,采用9自由度三轴空间整车模型,以三跨连续箱梁桥为研究对象,建立车桥耦合方程,利用ANSYS软件二次开发语言APDL进行仿真分析。研究分析了在弹性支承下,支座刚度、路面不平整度、车速以及行车间距对大跨连续梁桥车桥耦合动力响应的影响。研究结果表明,当支座刚度较小时,支座刚度变化对桥梁动力响应的影响较大,而当支座刚度较大时,支座刚度变化对桥梁的动力响应较小;路面等级越低,桥梁振动频率越趋向于低频化,当与桥梁固有频率接近时,动力响应尤为激烈;车速与行车间距对跨中挠度影响不大,对冲击系数与加速度幅值有较大影响,控制行车速度,保持良好车距可以有效减少车桥耦合振动响应。

In order to investigate the vehicle-bridge coupling vibration response of the beam bridge with elastic support,a spring-damping element was used to simulate the bearing,a nine-degree-of-freedom three-axis space vehicle model was adopted,and a three-span continuous box girder bridge was taken as the research object.The vehicle-bridge coupling equation was established,and the secondary development language of ANSYS software APDL was used for simulation analysis.The influences of support stiffness,road roughness,speed and distance on vehicle-bridge coupling dynamic response of long-span continuous girder bridges under elastic support were studied and analyzed.The results show that when the bearing stiffness is small,the dynamic response of the bridge is greater,but when the bearing stiffness is large,the dynamic response of the bridge is smaller.The lower the pavement level is,the more the vibration frequency of the bridge tends to be low frequency.When it is close to the natural frequency of the bridge,the dynamic response is particularly intense.Vehicle speed and distance have little influence on mid-span deflection,but have great influence on impact coefficient and acceleration amplitude.Controlling running speed and maintaining good distance can effectively reduce vehicle-bridge coupling vibration response.