移动荷载作用下简支梁振动减振分析

Vibration Reduction Analysis of Simply Supported Beam Under Moving Load

振动控制是解决大跨轻质人行天桥舒适度的关键问题之一。通常会采用调谐质量阻尼器(TMD)进行减振,可以有效降低桥梁在行人激励下的振动反应。将行人激励简化为移动简谐荷载,建立人群-人行桥-TMD振动系统,推导在匀速移动人行荷载下,人群-人行桥-TMD振动系统的运动微分方程。并结合某一人行天桥实例,对该人行天桥进行添加TMD后的Simulink仿真分析,与Ansys建模分析的结果进行对比,说明Simulink仿真分析的正确性。采用中国规范进行舒适度分析,选取一定范围人行荷载的频率,并用Simulink对此简支梁桥进行定质量TMD与变质量TMD的减振分析,分析结果表明变质量TMD减振效果优于定质量TMD减振效果。

Vibration control is one of the key issues to solve the comfort of a large span lightweight pedestrian bridge.The tempered mass damper(TMD)is usually used for vibration reduction,which can effectively reduce the vibration response of the bridge under pedestrian excitation.The pedestrian excitation is simplified to the mobile harmonic load,and the crowd-footbridge-TMD vibration system was established.The differential equations and state equations of the crowd-footbridge-TMD vibration system under the uniform moving pedestrian load were derived.Combined with a pedestrian bridge instance,the Simulink simulation analysis of the pedestrian bridge after adding TMD was compared with the results of Ansys modeling analysis.The accuracy of Simulink simulation analysis was illustrated.The Chinese standard was used for comfort analysis,the frequency of a certain range of pedestrian loads is selected,and the vibration reduction analysis of the traditional TMD and the variable mass TMD was carried out on the simply supported beam bridge by Simulink.The analysis results show that the variable mass TMD damping effect is better than the traditional TMD vibration reduction effect.