基于H_(2)范数的大跨人行桥舒适度TMD控制

TMD Control of Comfort Level for Large-span Footbridge by the H_(2) Norm

海心桥是跨越珠江的大跨度钢结构、斜拱曲梁组合人行桥,其构造与受力复杂,满足人行舒适度是要解决的关键问题之一,而设置调谐质量阻尼器(TMD)是振动控制的有效方法。本文基于ANSYS建立海心桥有限元模型,分析桥梁动力特性,基于阻尼器工作原理和H2范数控制法实现参数优化。对海心桥进行减振效果分析,并与一定质量比范围内使TMD减振效率最高的Den Hartog经典控制法进行对比。研究表明:加装TMD后各阶敏感模态减振效果明显,最大减振率可达74%,尽管经典控制法的减振效果更优,但其TMD质量为H_(2)控制法的2~5倍,减振率仅提高4%至20%,H2范数控制法可通过较低的TMD造价达到舒适度控制的目的。

Haixin Bridge is a long-span steel footbridge with inclined arch and curved beam spanning the Pearl River.Its mechanical behavior is very complicated,so meeting the pedestrian comfort is one of the key problems to be solved,and installation of tuned mass damper(TMD)is an effective method to control the vibration.In this paper,the finite element model of the Haixin Bridge is established based on ANSYS,the dynamic characteristics of the bridge are analyzed.The control parameters of TMD are optimized based on its working principle and the H_(2) norm control method.The vibration reduction of the bridge are analyzed,and compared with the Den Hartog classical control method that has the highest vibration reduction efficiency of TMD within a certain mass ratio range.The studies show that after installing the TMD,the vibration reduction in each order of sensitive mode is obvious,and the maximum rate of vibration reduction can reach 74%.Although the vibration reduction of the classical control method is better,the total mass of installed TMD is about 2~5 times that by the H2 norm control method,while the rate of vibration reduction is only increased by 4%~20%.Consequently,the H2 norm control method can control the pedestrian comfort by lower TMD’s cost.