小波分析在桥梁结构损伤检测中的应用

大型土木建筑结构在长期使用过程中会因各种因素而产生损伤和结构强度退化,如果没有及时发现和采取必要的措施,将可能发生严重的事故,造成生命和财产的巨大损失。利用结构的振动特性的变化评估其健康状况,是当前研究的热点问题。本文基于结构振动测试和小波变换技术,确定结构可能发生的整体性能退化或局部损伤的大小和位置,以便应用于大型结构尤其是桥梁结构的在线损伤检测中。首先通过数值模拟分析得到结构的振动响应信号,再经过小波分析得到各阶子信号,进而获得各阶子信号的能量谱及损伤前后能量谱的变化。通过观察各阶子信号的差异和能量谱的变化评价结构的损伤状态。

Application of Wavelet Analysis in Damage Detection of Bridge Structure

Performance degradation of large structures will inevitably occur because of various factors as well as structural damage,which will result in structural collapse if not have been found in time.The damage of structure leads to a variation of structural modal parameter;so the wavelet transform for damage detection is introduced in this paper for considering the variation.First,structural dynamic response signal on the basis of the vibration-based structural damage diagnosis methods is calculated by structural analysis,then,each sub-signal is calculated according to wavelet analysis.The sub-signal energy spectrum of dynamic response signal and energy spectrum variation are known,by observing the difference between the sub-signal and the variation of the sub-signal energy spectrum,we can get the variation of structural modal parameter and the sub-signal energy spectrum due to the performance degradation of the whole structure and local variations of damage level and location,thus,this method can be used in the on-line damage detection of bridge structures.