The strain sensitivity coefficient for a surface-mounted fibre optic sensor is strongly affected by the type of adhesive material used for its installation. In the present study, appropriate strain correction factors have been investigated to modify the strain sensitivity coefficient for surface mounted fibre Bragg gratings to achieve accurate strain data. The experimental study adopts a fibre optic sensor (FOS) mounted on a carbon fibre reinforced polyphenylene sulphide specimen using two adhesive types, i.e. a cyanoacrylate and an epoxy-resin. For comparison purposes strain data was also captured using strain gauge, contact extensometer and digital image correlation instrumentation. The experiments reveal that the predicted correction factors vary considerably with the adhesive material used for the mounting of the FOS. Further analysis demonstrates that a 37 % deviation in the value of the correction factor results in a 27 % variation in the strain output. In addition, the microscopic image analysis confirmed that the thickness of the adhesive layer between FOS and the substrate affects the strain sensitivity of FOS and plays a crucial role in transmitting the deformation of the host material to the sensing element.

表面安装的光纤传感器的应变灵敏度系数受其安装所使用的粘合材料类型的强烈影响。在本研究中，已经研究了适当的应变校正因子，以修改表面安装的光纤布拉格光栅的应变灵敏度系数，以获得准确的应变数据。该实验研究采用了一种光纤传感器（FOS），该传感器使用两种粘合剂类型（氰基丙烯酸酯和环氧树脂）安装在碳纤维增强的聚苯硫醚样品上。为了进行比较，还使用应变仪，接触式引伸计和数字图像相关仪器捕获了应变数据。实验表明，预测的校正系数随用于FOS安装的粘合剂材料的不同而有很大差异。进一步的分析表明，校正系数的值出现37％的偏差会导致应变输出出现27％的变化。另外，显微图像分析证实了FOS和基底之间的粘合剂层的厚度影响了FOS的应变敏感性，并且在将主体材料的变形传递给感测元件方面起着关键作用。