双斜锥光纤布拉格光栅超声波传感装置  

Design of Fiber Bragg Grating Ultrasonic Sensor with Dual-Slant Cone Structure

作　　者：李剑芝[1] 史宇承 吉喆 徐飞 杜彦良 Li Jianzhi;Shi Yucheng;Ji Zhe;Xu Fei;Du Yanliang(Key Laboratory of Structural Health Monitoring and Control,Shijiazhuang Tiedao University,Shijiazhuang 050043,Hebei,China;School of Materials Science and Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,Hebei,China;School of Mechanical Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,Hebei,China)

机构地区：[1]石家庄铁道大学河北省大型结构健康诊断与控制重点实验室,河北石家庄050043 [2]石家庄铁道大学材料科学与工程学院,河北石家庄050043 [3]石家庄铁道大学机械工程学院,河北石家庄050043

出　　处：《光学学报》2024年第11期30-39,共10页Acta Optica Sinica

基　　金：国家自然科学基金(51778379);河北省中央引导地方项目(226Z0801G);河北省省级科技计划资助(21567625H)。

摘　　要：为提高光纤布拉格光栅(FBG)在超声波探测中的灵敏度和复用能力,设计并实现一种基于聚能耦合效应的双斜锥FBG超声波传感装置。首先,利用锥聚能理论与有限元法,分析锥形结构对超声波的聚焦作用。其次,详细讨论双斜锥FBG的结构参数(斜锥锥角、底面直径、高度、倾斜度)对其聚能效果的影响,确定传感装置最优尺寸。最后,制作传感装置并测试其动态特性。结果表明,封装后的双斜锥FBG超声波传感装置在20~130 kHz工作频率范围内可有效提高FBG检测超声波灵敏度。当工作频率增加到50 kHz时,检测幅值提升了约21倍,且传感响应的线性度良好。设计的超声波传感装置可实现双端输出,具有复用性,可应用于钢轨、桥梁等长距离结构的健康监测。Objective Railway transport is an important part of China’s transportation strategy and is still in the high-speed construction stage,with its total operation mileage reaching 1.59×105 km.As the direct carrier of train operation,the inside and surface of rails will have a variety of defects and damages due to long-term operation and vibration shock.What’s worse,this will directly endanger the safety of trains and passengers if defects or damages are not found and repaired in time.At present,piezoelectric sensors are usually employed to detect ultrasonic rail damage and each of them needs a power line connection,which makes it difficult to achieve multi-point multiplexing detection.In contrast,optical fiber Bragg grating(FBG)has the unique advantages of electromagnetic interference resistance,easy reuse,and corrosion resistance,which makes it suitable for damage detection of long-distance structures such as steel rails in harsh environments.To detect ultrasonic waves,we propose and design a high-sensitivity FBG ultrasonic sensor based on a coupled dual-slant cone structure.Meanwhile,the optimal size of the sensor is analyzed and determined,with the sensor object made.The dynamic characteristics of the sensor are tested experimentally,with a new approach provided for longdistance structure ultrasonic detection.Methods First,the optimal sensor size is obtained.Based on the mechanism of FBG and ultrasonic waves and the principle of slant conical energy accumulation,the slant conical sensor is modeled and solved by COMSOL simulation software 6.0.The amplitudes of ultrasonic signals detected by non-conical,positive conical,and slant conical structures are analyzed and compared respectively.The influence of slant conical structure parametersβ,d,H,and i on the sensor performance is studied in detail.Then,three-dimensional(3D)printing technology is adopted to make the entity of the sensor device.After that,a narrow-band light source demodulation system is built to detect ultrasonic signals of different frequencies.F

关 键 词：光纤光学 光纤布拉格光栅 双斜锥 超声波传感器 斜锥聚焦 

分 类 号：TN247[电子电信—物理电子学]