基于光纤布拉格光栅振动传感器和极限学习机的工字钢梁损伤识别  

Damage Identification of I-Beam Based on Fiber Bragg Grating Vibration Sensor and Extreme Learning Machine

作　　者：李亦佳 王正方[1] 王静[1] 隋青美[1] Li Yijia;Wang Zhengfang;Wang Jing;Sui Qingmei(School of Control Science and Engineering,Shandong University,Jinan,Shandong 250061,China)

机构地区：[1]山东大学控制科学与工程学院,山东济南250061

出　　处：《中国激光》2021年第16期164-175,共12页Chinese Journal of Lasers

基　　金：国家自然科学基金(41877230);山东省重点研发计划(2019GGX01027);山东省自然科学基金(ZR2018MEE052)。

摘　　要：围绕工字钢梁损伤识别问题,研制了一种新型双端固定梁结构光纤布拉格光栅(FBG)振动传感器,实现了工字钢梁振动响应的有效获取。在此基础上,研究了工字钢梁损伤自动识别方法,利用其对FBG振动传感器获取的振动响应进行处理。该方法采用小波包能量比变化偏差(ERVD)作为损伤特征,进而基于极限学习机(ELM)算法实现工字钢梁损伤状态识别。传感器仿真模拟和实验测试结果表明:设计的FBG振动传感器频率响应范围为10~350 Hz,在加速度响应范围为0.2g~3.0g时,灵敏度为6.7 pm/g,具有良好的线性度和横向抗干扰能力。工字钢梁损伤识别实验结果表明:所提方法对工字钢梁的损伤状态识别准确率达到96.7%,与常规的基于back propagation(BP)神经网络的损伤识别方法相比,准确率提高了3.4个百分点。Objective The potential damages of an I-beam structure may lead to safety accidents and adversely affect the safe operation of large-scale infrastructures such as buildings and bridges.The structural state monitoring and damage identification of an I-beam are critical to ensure its safe operation.Compared with traditional electronic-based vibration monitoring techniques,the fiber Bragg grating(FBG)sensor is small,high in sensitivity,antielectromagnetic interference,and easy multiplexing.It is thus preferred to be employed for collecting the vibration signal of the I-beam structure of the infrastructure.However,the existing FBG vibration sensors are difficult to meet the requirements of wide frequency response and high sensitivity measurement of I-beam.Therefore,the first issue to be solved is the accurate sensing techniques of vibration signals.Apart from vibration sensing,another issue to be tackled lies in the damage identification of I-beam structure.The neural network and its transformer-based identification methods that have been developed recently depend on a large amount of training data and are slow in training,which limit its generalization in practical applications.To solve the aforementioned two issues,a novel FBG vibration sensor with two ends fixed beam was designed for vibration sensing.Moreover,the extreme learning machine(ELM)algorithm was employed to identify the damage state of the I-beam.We hope the results can be helpful to promote the safety monitoring and damage evaluation techniques of I-beam structures.Methods In this paper,a novel FBG vibration sensor with a double-ended fixed beam structure was designed,and the ELM-based automatic damage identification method of the I-beam was studied.First,a novel I-shape beam structure was designed as vibration-sensitive components of the FBG sensor.Then,we performed finite element simulations as well as testing experiments on the sensor to test its performance.After that,the energy ratio variation deviation(ERVD)of the wavelet packet was extracted as

关 键 词：光纤光学 光纤布拉格光栅振动传感器 能量比变化偏差 极限学习机 损伤识别 

分 类 号：TP212.9[自动化与计算机技术—检测技术与自动化装置]