基于光纤光栅应变传感的基本原理以及粘弹性力学的基本理论,建立了一种简化的光纤光栅应变传感器光力转换的时变方程。方程的建立忽略封装基体和纤芯的粘弹性力学行为,同时综合考虑观测环境封装基体粘结层(或涂层)光纤纤芯之间的弹性和粘弹性力学耦合机制。所建立的方程既包含了传感器的所有几何特征参数和力学特征参数,又可大为简化光力转换的时变分析过程,从而为光纤光栅应变传感应用于大型工程结构健康监测的长期性能评估(包括参数标定、信号校正、精度分析及误差估算)提供较为可靠、实用、简便的理论分析工具。

Based on the basic principle of fiber optical Bragg grating (FBG) strain sensing and the basic theory of viscoelastic mechanics,a simplified time-dependant optical-mechanical transformation equation for FBG sensors is established. With the viscoelastic mechanic behavior of encapsulation matrix and optical fiber core being neglected and the elastic-viscoelastic mechanic coupling mechanism among environment-encapsulation matrix-adhesion layer-optical fiber core being taken into account,the equation hereby established contains all the characteristic geometric and mechanical parameters of a sensor,and can greatly simplify the process of optical-mechanical transformation analysis,thereby more reliable and less complicated for long-term performance analysis of FBG sensors when applied to health monitoring of large project.