报道了一种分析包覆光纤布拉格光栅(FBG)传感器应力传递规律的方法。利用剪滞法理论将光纤布拉格光栅和其包覆材料看成一种复合体,从力学角度分析光纤布拉格光栅被包覆后的应力传递规律,得到当光纤布拉格光栅一定时,被包覆光纤布拉格光栅的应力传递系数仅与包覆材料的尺寸和杨氏模量有关。采用三种不同的包覆材料(聚合物、毛细钢管和毛细铜管)对光纤布拉格光栅进行了多个半径的封装,验证包覆光纤布拉格光栅的应力传递系数,实验证明,理论结果和实测数据基本吻合。

A method to analyze the stress-transferring rule of claded fiber Bragg grating (FBG) sensor is reported. Considering the FBG sensor together with its cladding material as a composite, the shear lag theory is applied to analyze the stress-transferring rule of claded FBG sensor. It is shown that the stress-transferring coefficient of FBG sensor is only related to the radius and Young′s module of cladding material. In the experiments, the FBG sensors claded by three kinds of cladding materials (polymer, steel capillary and copper capillary) with different radii are utilized to validate the stress-transferring rule. The experiment results are in generally good agreement with the theoretical analysis.