摘要
对润扬大桥悬索桥结构的实测加速度响应进行了小波包分析,详细地考察了环境激励下悬索桥实测小波包能量谱的环境变异性.分析结果表明,实际环境条件(交通荷载、环境温度和台风荷载)与悬索桥实测小波包能量谱存在较为明显的相关性,主要表现为环境温度的变化对小波包能量谱的影响是长期性的趋势,而交通荷载的影响则由于荷载的非平稳性呈现瞬时的颤动变化.实测数据的分析结果进一步表明,环境温度和台风作用对于小波包能量谱的影响规律存在着较为明显的差异.相比模态频率而言,利用小波包能量谱可以更敏感地发现大跨悬索桥结构的振动特性变化.因此,基于小波包能量谱的结构损伤预警参数更适合于环境振动测试下的大跨悬索桥整体状态监测.
The wavelet packet analysis is performed using the measured acceleration responses of Runyang suspension bridge,on the basis of which the environmental variability of the measured wavelet packet energy spectrum（WPES） is discussed in detail using ambient vibration tests.The analysis results reveal that the actual environmental conditions including traffic loadings,environmental temperature and typhoon loadings have remarkable correlations with the measured WPES of Runyang suspension bridge.The changes of environmental temperature have a long-term trend influence on the WPES,while the effect of traffic loadings on the measured WPES of the bridge presents instantaneous changes because of the nonstationary properties of the loadings.In addition,the influences of environmental temperature and typhoon loadings on the WPES show distinct differences.Compared with modal frequency of the bridge,the WPES can more sensitively detect the changes in the dynamic properties of the bridge.Therefore,the WPES-based structural damage alarming parameters are more suitable for online condition monitoring of long-span suspension bridges under ambient vibrations.
出处
《东南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2009年第1期91-95,共5页
Journal of Southeast University：Natural Science Edition
基金
国家杰出青年科学基金资助项目(50725828)
国家自然科学基金资助项目(50808041)
江苏省自然科学基金资助项目(BK2008312)
关键词
悬索桥
小波包分析
小波包能量谱
环境振动
结构损伤预警
suspension bridge
wavelet packet analysis
wavelet packet energy spectrum
ambient vibration
structural damage alarming
