基于光纤光栅的飞机结构载荷谱构建新方法研究

Aircraft load spectrum is an indispensable scientific basis for estimation and extension of aircraft fatigue life, as well as reliability assessment of aircraft structure, meanwhile it serves as key technology for ensuring the security and reliability within the aircraft economical life. At present, among aircraft load measurement techniques, especially strain-meter based ones adopted mainly in structure load measurement, some technical conundrums still exist, such as poor anti-interference performance, short operational life of monitoring system which could not reaching the amount of fatigue life of structural details monitored.Taking key structure of an aircraft, wings as research object, we propose new FBG-unit based techniques towards aircraft spatial loads measurement and structural damage monitoring, so as to break through the technical conundrums and bottlenecks mentioned above. The main research contents and innovative points, stated as follows. 1) First, two FBG-unit based models are established. One is spatial load measurement model and the other is damage transformation model; 2) Then FBG-unit suitable for aircraft load measurement would be investigated, while other problems would be tackled, such as the fusion of FBG-unit with aircraft structure surface, signal temperature compensation, FBG-unit layout optimization and so on;3) Finally, to establish FBG-unit based techniques towards wing load measurement and data acquisition system.The research would provide the new theory and techniques for fatigue life assessment of aircraft structure and monitoring of key structures, with broad application prospects, and also highly important scientific significance and engineering value to ensure the flight safety.

飞机载荷是飞机结构定寿、延寿和飞机结构可靠性评定不可或缺的科学依据，是保障飞机经济寿命内安全性与可靠性的关键技术。目前飞机载荷实测，尤其是对结构载荷测试主要采用电测应变计法，存在抗干扰性差、使用寿命短致使无法与监测部位同寿等技术难题。本项研究为解决上述技术难题和瓶颈，以某型飞机的关键结构—机翼为研究对象，提出基于光纤光栅技术的飞机空间载荷测量与结构损伤监测的新方法。主要研究内容及创新点：1)建立基于光纤光栅的空间载荷测量和损伤转换模型；2)研究适用于飞机结构载荷测量的光纤光栅监测单元，解决监测单元与飞机结构表面融合、温漂补偿、监测部位优化等问题；3）建立基于光纤光栅监测单元的机翼载荷测量方法与数据采集系统。该项研究可为飞行器结构寿命评定与关键结构寿命监测提供一种新理论和新方法，应用前景广阔，对保障飞行安全具有重要的科学意义和应用价值。

本项目针对飞行器的飞行状态参数监测、健康监控应用背景，力求解决高强度光纤光栅传感技术和多参量光纤网络技术问题，其难点在于传感器可靠性和大容量多参量组网。重点完成了高强度光纤光栅的制备工艺及应变、温度传感器结构封设计与特性测试，大容量光纤传感网络复用，高速解调仪并行数据融合，多参量光纤传感光谱数据的实时处理与传输，小型飞机机身上完成实时检测系统功能验证等研究内容，突破了多参量光纤传感器的高可靠封装、光纤传感信号的高速解调、多参量光纤光栅传感器的混合复用和组网数据融合等关键技术，研制了应变、温度传感器，多通道高速解调仪，千量级大容量飞机结构载荷光纤监测组网系统等原型系统和工程样机，通过实验室模拟环境试验、中国计量科学研究院测试、专家现场验收验证，达到了应变传感器测量范围±5000με、测量分辨率0.01%FS，温度传感器测量范围-50~300℃、测量分辨率0.1℃，网络总检测点1049点。其中，光纤光栅传感器及组网监测系统已在飞机的地面静力载荷谱测试和潇湘二号卫星飞行搭载试验等方面得到了验证，形成了飞机载荷谱系统参数实时检测光纤传感系统的集成能力。