基于光纤传感的风电机组叶片应变传递特性研究

针对在进行应变感知时光纤感知到的应变和叶片基体实际应变会存在一定偏差（即应变感知传递偏差）的问题,开展基于光纤传感的风电叶片应变感知传递特性研究,以建立应变传递分析模型。首先确定光纤光栅应变传感器布置策略,然后利用理论和数值仿真相结合分析载荷、光纤（纤芯）直径、包层（传感结构参数）、粘接剂厚度、光纤相对基体位置、叶片材料属性参数等对应变变化及其传递特征的影响,分别考虑表面粘贴式和嵌入式2种布置模式。最后,基于多因素的正交试验分析,通过回归分析建立光纤感知应变（传递值）与传感结构参数、光纤相对基体位置、材料属性之间的关系表达式。研究结果表明：随着光纤传感器植入深度的增加,应变传递大小以中性层为对称面对称分布;轴向杨氏模量E1、轴向和横向构成法平面内的剪切模量G12、轴向和纵向构成法平面内的剪切模量G31对2种布置形式的应变传递都有明显影响。

RESEARCH ON STRAIN SENSING TRANSMISSION CHARACTERISTICS OF WIND TURBINE BLADES BASED ONOPTICAL FIBER SENSING

Aiming at the problem that there will be a certain deviation （i.e. strain sensing transmission deviation） between the strain sensed by the optical fiber and the actual strain of the blade matrix during strain sensing, the strain sensing transmission characteristics of wind power blades based on optical fiber sensing are studied to establish the strain transmission analysis model. Firstly, the arrangement strategy of fiber bragg grating strain sensor is determined. Then, the effects of load, fiber （core） diameter, cladding thickness, adhesive thickness, relative position of optical fiber to blade matrix, blade material parameters on the strain and its transfer characteristics are analysed. Two layout modes, surface-attached and embedded, are considered respectively. Finally, based on the orthogonal experimental analysis of multiple factors, the relationship expression between optical fiber sensing strain （transmission value） and sensing structure parameters, optical fiber relative matrix position and material properties is established through regression analysis. The results show that the strain transfer is distributed symmetrically on the neutral layer with the increase of the embedded depth of optical fiber sensor. Young’s ModulusE1, Shear ModulusG12and Shear modulusG31have obvious effects on the strain transfer of both the two layout modes.