光纤传感元结构材料对其温度响应的影响研究

光纤传感元的结构形式和材料组成会影响温度作用下光纤的实际变形,从而影响其具体传感特性.理论分析并推导了温度作用下涂覆光纤和套塑光纤实际变形的表达方程式,定义了对应具体光纤结构的等效热膨胀系数.建立了涂覆光纤和套塑光纤的有限元仿真计算模型,具体研究了各层材料间沿轴向和径向的应力和变形分布规律.在此研究基础上分析了涂覆光纤光栅以及干涉型光纤传感器的温度响应公式的具体表达形式,研究结果同样适用于其它各类本征型光纤传感器的温度响应分析.

Research on the Temperature Response of Optical Fiber Sensing Elements with Different Structures and Materials

The actual deformation of fiber sensing elements will be different if it has different structures and materials, which will influence the sensing characteristics of optical fiber. The actual deformation expressions of coated and jacketed fiber under temperature were analyzed and deduced. The equivalent coefficients of thermal expansion corresponding to the optical fibers with certain structures were also defined. Moreover, finite element models of coated and jacketed fiber were developed to study the distribution rules of axial and radial thermal stress and deformation of fiber. Based on the above analyses, the specific temperature response formulas of coated fiber grating and interference optical fiber sensor were studied. The analyses are also suitable for the temperature response of other intrinsic optical fiber sensors.