EVA增敏的光纤光栅径向压力传感特性研究

Study on Radial Pressure Sensing Characteristics of EVA Sensitivity Enhanced Fiber Grating

提出了一种采用乙烯-醋酸乙烯共聚物（EVA）封装增敏的光纤光栅径向压力传感方案,将光纤光栅用EVA材料和方钢封装成半哑铃型传感单元,利用有限元软件对结构体受力分布进行了仿真,理论分析了传感单元在径向压力作用下的响应特性,并建立实验系统对光纤光栅径向压力传感特性进行验证。研究结果表明：当径向压力在0~0.3 N范围内时,封装后的光纤光栅对径向压力响应具有很好的线性度;对径向压力的灵敏度相对于裸光栅提高了100.74倍,经匹配法解调后,系统的灵敏度最高可以达到0.94 nm/N;对于解决微小径向应变精确测量的实际工程需求具有重要的参考意义。

A novel fiber grating radial pressure sensitivity enhanced scheme, which is encapsulated with ethylene- vinyl acetate copolymer （EVA）, is presented. The fiber grating is encapsulated into a half dumbbell-shaped sensing unit with EVA material and square steel. And the structure stress distribution and radial pressure response characteristics of the sensor are calculated theoretically with finite element software. Finally, an experiment system is established for verifying the sensing characteristics of the sensitivity enhanced optic fiber grating radial pressure sensors. The experiment results show that when the radial pressure is ranged from 0 to 0.3 N, the encapsulated sensors have excellent linearity to radial pressure. And the sensitivity is 100.74 times higher than that of naked optical fiber grating. Further more, after demodulation with the matching method, the sensitivity of the system can be up to 0.94 nm/N. The research results have an important reference significance for solving the practical engineering requirements for accurate measurement of micro radial strain.