基于SPC与小波变换的光纤光栅型损伤识别

Damage Identification Technology Based on Fiber Bragg Grating Using SPC and Wavelet Transform

为了研究光纤光栅传感技术在振动型损伤识别技术中的优势,建立了基于非平衡M-Z干涉仪和PGC相位解调技术的光纤光栅结构损伤识别系统;构建了基于小波包节点能量相对变化率之和的结构损伤识别指标;介绍了统计过程控制原理,推导了均值-极差控制图进行结构连续损伤识别的过程;测试了结构处于健康状态和6种损伤状态下的振动信号并分析了损伤识别。试验结果表明,构建的损伤识别系统能判断损伤的存在,并且能对损伤的位置和损伤程度进行有效识别。

In order to study the merits of fiber bragg grating(FBG) sensor in vibration damage identification,an interrogation based on unbalanced M-Z interferometer and PGC is designed.The damage indicator,sum of relative variation ratio,is constructed based on wavelet packet node energy.The principle of statistical process control is introduced and the damage identification process using Xbar-R chart is derived.The vibration signals under health status and six kinds of damage status are measured using FBG interrogation.Results show that the damage indicator can judge the presence of damage,the location of the damage and the quantification of the severity of the damage.