桥梁损伤自动检测理论初探

自动检测是桥梁健康监测的核心和关键技术之一,在自动检测确定出损伤大致范围的基础上,可以通过人工检查进一步确认或排除损伤点,这可大大减轻损伤检测的劳动强度,节约开支。根据小波变换多分辨率分析的特性和恒虚损处理自动检测原理,形成以小波恒虚损处理方法为核心的桥梁损伤自动检测理论。该方法通过拾取环境噪声作为参考噪声,与试验信号分别经相同小波滤波器输出后,形成统计量作为恒虚损率处理的输入参数,进而对奇异信号进行自动检测。该技术不需要无损桥梁相关资料,并可满足实时动态监测的要求。最后通过算例进行了验证。

Research on Theory of Bridge Automatic Damage Detection

Automatic detection is one of key techniques of bridge health monitoring.On the basis of locating the approximate damage location by automatic detection,one can furthermore confirm or exclude the damage location by manpower.This method can decrease labor intensity and cost dramatically.A theory of automatic damage detection of bridge structure is proposed centering on the wavelet constant false damage rate (WCFDR) method,according to the multi-resolution characteristic of wavelet transform and the automatic detection theory of CFDR.Singularities are detected automatically by means of the method of CFDR,which uses the statistical parameters as input data which are output as a result of filtering of the noise,which is as the reference noise acquisitioned from the circumstance,and the test signal from the identical wavelet filters.This technique need no pertinent information about the undamaged bridge and can satisfy the need of dynamic real time monitoring.A numerical case simulates this automatic detection procedure successfully in the end.