大跨径石拱桥动力特性分析与有限元模型修正
Dynamic Analysis and Finite Element Model Updating of Long-Span Stone Arch Bridge
刘杰 1陈顺超 1邬文祥 1康鹏 1宋帅 1聂良鹏 2游鹏升2
作者信息
- 1. 西南林业大学,云南 昆明 650224
- 2. 云南通衢工程检测有限公司,云南 昆明 650200
- 折叠
摘要
[目的]研究云南省开远市长虹桥动力性能及得到较为准确的有限元分析模型.[方法]通过环境激励法对长虹桥进行动力特性测试,并分析该桥实测模态参数;根据实测模态参数结果,对有限元模型中的弹性模量、泊松比等参数进行修正;基于理论与实测的模态分析结果,得出长虹桥较为准确的有限元分析模型.[结果]结果表明:石拱桥的跨中、L/4、3L/4、L/8和7L/8处的振动变形较大,在运营监控和检测时,应该在这5个位置布置测点,以便进行实时监测;在环境激励下,该桥没有产生侧向弯曲振动和竖向弯曲振动强度相当的扭转振动,说明结构具有良好的抗扭刚度;各阶阻尼比均在合理范围内.利用模态参数修正后的频率相关性从55.2%降至最低0.6%,数值计算结果与试验结果基本一致,参数依然具有物理意义,修正后的有限元模型能够较为准确地反映结构低阶动力特性.相关性最大为-2.4%,最小为0.6%,满足相关性在±5%以内,可作为桥梁后续检测工作的理论模型.[结论]长虹桥动力性能良好,修正后的有限元模型贴合实际桥梁.
Abstract
[Purposes]This paper aims to obtain the dynamic performance of the Changhong Bridge in Kaiyuan City,Yunnan province and to ensure a more accurate finite element analysis model.[Methods]The dynamic characteristics of the Changhong Bridge are tested by the method of environmental excita-tion,and the measured modal parameters are analyzed;according to the results of the measured modal parameters,the parameters such as elastic modulus and Poisson's ratio in the finite element model are modified;based on the theoretical and measured modal analysis results,a more accurate finite element analysis model of Changhong Bridge is obtained.[Findings]The results show that the vibration deforma-tion of stone arch bridge is large at mid-span,L/4,3L/4,L/8 and 7L/8,and the measuring points should be arranged at these five locations for real-time monitoring.Under ambient excitation,the bridge doesn't produce torsional vibration with equal strength between lateral and vertical bending vibration,which shows that the structure has good torsional stiffness and the damping ratios are in a reasonable range.Using the modified modal parameters,the frequency correlation is reduced from 55.2%to a mini-mum of 0.6%.The numerical results are basically consistent with the experimental results,which means parameters still have physical meaning.The modified finite element model,which can be used as a theo-retical model for the follow-up detection of bridges,can accurately reflect the low-order dynamic charac-teristics of the structure:the maximum correlation is-2.4%,the minimum is 0.6%,and the correlation is within±5%.[Conclusions]The dynamic performance of Changhong Bridge is good,and the modified finite element model fits the actual bridge.
关键词
环境激励法/动力特性/有限元模型修正/频率相关性Key words
environmental excitation method/dynamic characteristics/finite element model updating/fre-quency correlation引用本文复制引用
基金项目
云南省交通运输厅科技项目(云交科教便[2020]91号)
出版年
2024
NETL
NSTL
万方数据