耦合封装-粘结-连接疲劳特性的叶片测试FBG传感器可靠性评价

Full-scale testing of wind turbine blades is a necessary means to ensure the safety of wind turbine blades in operation and load-bearing and the strain measurement is very important. Reliable packaging, bonding and connecting technology are prerequisites for accurate strain measurement by FBG sensors. This project takes the FBG sensor encapsulated with carbon fiber as the research object, and takes the full-scale fatigue test of blades as the application background, aiming at improving the reliability of the FBG sensor encapsulated with carbon fiber as the target. Focusing on the problem that the reliability of the FBG sensor decreases due to the fatigue failure and performance degradation of the encapsulated connection, the fatigue life and performance of the encapsulated layer, the bonded layer and the joint under alternating The degradation law reveals the influence of fatigue failure and performance degradation of packaging layer, bonding layer and joint on the reliability of carbon fiber encapsulated FBG sensor. The degradation process of multi-performance parameters and the attenuation characteristics of strain transfer of FBG sensor under alternating loads are studied, and the reliability evaluation index and algorithm of FBG sensor considering packaging-bonding-bonding fatigue failure and performance degradation are proposed. To develop the reliability evaluation technology of FBG sensor considering packaging and bonding process, the reliability evaluation rules of FBG sensor network are established. The research results can provide a reference for the bonding design of carbon fiber encapsulated FBG sensors, and provide a method for the reliability evaluation of carbon fiber encapsulated FBG sensors.

风电叶片全尺寸测试是保障叶片运行与承载安全的必要手段，叶片测试中应变测量极为关键，可靠的封装、粘结、连接工艺是保证FBG传感器准确测量应变的先决条件。本项目以碳纤维封装FBG传感器为研究对象，以叶片全尺寸测试为应用背景，以提高FBG传感器使用可靠性为目标，围绕封装连接疲劳失效和性能退化造成FBG传感器可靠性降低的问题，深入研究交变载荷下封装层、粘结层、连接接头的疲劳寿命和性能退化规律，揭示封装层、粘结层、连接接头疲劳失效及性能退化对FBG传感器可靠性的影响机理；研究交变载荷下FBG传感器多性能参数退化过程和应变传递衰减特性，提出耦合封装-粘结-连接疲劳失效和性能退化的FBG传感器可靠性评价指标及其算法，形成FBG传感器可靠性评定规程，发展考虑封装连接工艺的FBG传感器可靠性评价技术。该研究成果可为碳纤维封装FBG传感器的封装粘结连接设计提供参考，为碳纤维封装FBG传感器可靠性评价提供方法。

本项目针对封装连接疲劳失效和性能退化造成FBG传感器可靠性降低的问题，搭建了FBG传感器疲劳试验与测试平台，研究了封装层、粘接层、连接结构疲劳失效对FBG传感器可靠性的影响，研究了交变载荷下FBG传感器多性能参数退化规律；完成了封装FBG传感器可靠性分析，确定了其可靠性薄弱环节；基于试验与仿真，提出了基于应变传递效率、多性能参数退化的封装FBG传感器可靠性评估方法；基于分布式应变测量数据，提出了基于GWO-LSSVM、EWM-MADM等智能算法的应变预测方法。通过以上研究，本项目发现在试验过程中，封装粘接工艺对FBG传感器应变测量精度影响较大，带来应变测量结果较强的分散性和不确定性，因此在样本制作过程中，封装、粘接的一致性尤为重要；相对于其他因素，粘接层的厚度对应变测量结果影响较大，因此在具体使用过程中，应控制粘接厚度的一致性，并做好周期性校准；交变载荷下封装FBG传感器的封装层、粘接层疲劳损伤将直接影响应变传递效率、应变灵敏度和重复性，需要综合多个性能参数进行FBG传感器可靠性评价；本项目基于分布式应变测量数据进行了未测点应变预测，发现叶片结构应变与载荷大小及位置相关性较强，机器学习可用于关键位置未测量点的应变预测。本项目可为FBG传感器的封装、粘接和连接制备工艺提供依据，为封装FBG传感器使用过程中的可靠性评估和准确度评价提供方法，为传感器应变测量数据的分析与应用提供思路。