微纳耦合光纤模态声发射传感特性优化研究  

Study on sensing characteristic optimization of micro/nono coupling fiber based on modal acoustic emission

作　　者：刘懿莹[1] 王霖洁 付文成 李凤梅 冀敏慧 

机构地区：[1]西安交通大学电气学院,西安710049

出　　处：《仪器仪表学报》2017年第11期2725-2734,共10页Chinese Journal of Scientific Instrument

基　　金：中国博士后科学基金(2017M613119)项目资助

摘　　要：为了改善微纳耦合光纤传感器声发射模态识别的能力,立足于模态声发射理论,实验研究了微纳耦合光纤有效传感区结构、长度以及对称性对传感器模态识别能力的影响,分析了优化后传感器模态识别能力的定向性。实验结果表明,当有效传感区结构为包括分离区、锥区和腰区的"X"型结构时,传感器不能识别S_0模态,且识别的A_0模态完整性差;当有效传感区结构为包括腰区和全部锥区的"---"型结构时,传感器能够识别出S_0模态,并完整地识别A_0模态;当有效传感区对称时,所测信号模态完整性好;而当有效传感区不对称时,所测信号完整性较差;"X"型结构时,分离区会衰减声波的部分能量,传感器灵敏度随着有效传感区长度的减小而增大;"---"型结构时,由于锥区起到应变放大作用,传感器灵敏度会随着锥区长度的减小而降低;传感器的模态识别能力随着检测角度的减小而减弱,其有效检测角度范围为45°~135°。该研究对本传感器应用于模态声发射具有指导意义。In order to improve the ability of acoustic emission modal recognition of Micro/nono Cupling Fiber Sensor （MCFS）, based on the theory of modal acoustic emission, the influences of the effective sensing area structure, length and symmetry of micro/nono coupling fiber on the modal identification ability of the sensor has been studied in experiment, and the orientation properties of the optimized sensor have been analyzed. Experiment results show that： When the effective sensing area structure is ＂X＂ type, including separation zone, exact taper zone and waist zone, the sensor can＇t identify the SO modal and the integrity of the identified A0 modal is poor; when the effective sensing area structure is ＂---＂ type, including waist zone and all the exact taper zones, the sensor can identify the A0 modal and identify SO modal completely. When the effective sensing area is symmetric, the integrity of the measured signal is good; when the effective sensing area is asymmetric, the integrity of the measured signal is poor. For the＂ X＂ type structure, in the separation zone partial sound wave energy is attenuated, the sensitivity of the sensor increases as the length of the effective sensing area decreases ; however, for the ＂---＂type structure, the sensitivity of the sensor decreases as the length of the exact taper zone decreases due to the strain magnification effect of the exact taper. The modal identification ability of the sensor decreases as the detecting angle decreases, the effective detecting angle range is from 45° to 135°. This study has great significance to the application of this sensor in modal acoustic emission.

关 键 词：微纳耦合光纤 模态声发射 模态识别 传感性能优化 

分 类 号：TH74[机械工程—光学工程]