Matveenko Valerii, Kosheleva Natalia, Serovaev Grigorii, Fedorov Andrey
Institute of Continuous Media Mechanics, Ural Branch of Russian Academy of Sciences, 614068 Perm, Russia.
Sensors (Basel). 2021 Jul 26;21(15):5050. doi: 10.3390/s21155050.
The results of strain measuring experiments, with the help of rosettes consisting of fiber Bragg grating sensors (FBG) embedded at the manufacturing stage in a polymer composite material are considered in this paper. The samples were made by the direct pressing method from fiberglass prepregs. A cross-shaped sample was tested under loading conditions corresponding to a complex stress state. A variant of strain calculations based on experimental data is discussed. The calculations were performed under the assumption of a uniaxial stress state in an optical fiber embedded in the material. The obtained results provide a reasonable explanation of the absence in the conducted experiment of two peaks in the reflected optical spectrum, the presence of which follows from the known theoretical principles. The experimental result with two peaks in the reflected optical spectrum was obtained for the same sample under a different loading scheme. The proposed variant of the numerical model of the experiment and the results of numerical simulation made for FBG rosettes embedded in the material allowed to estimate error in the strain values calculated on the assumption of the uniaxial stress state in the optical fiber and in the presence of two peaks in the reflected optical spectrum.
本文研究了在聚合物复合材料制造阶段嵌入由光纤布拉格光栅传感器（FBG）组成的应变片进行应变测量实验的结果。样品由玻璃纤维预浸料通过直接压制法制成。对一个十字形样品在对应复杂应力状态的加载条件下进行了测试。讨论了基于实验数据的应变计算方法。计算是在假设材料中嵌入的光纤处于单轴应力状态下进行的。所得结果合理地解释了在进行的实验中反射光谱中没有出现两个峰值的情况，而根据已知理论原理应该会出现这两个峰值。在不同加载方案下，对同一个样品获得了反射光谱中有两个峰值的实验结果。所提出的实验数值模型变体以及针对嵌入材料中的FBG应变片进行的数值模拟结果，使得能够估计在假设光纤处于单轴应力状态且反射光谱中有两个峰值的情况下计算得到的应变值的误差。
