柔性基体材料封装FBG传感器的应变传递误差分析

由于力学理论和有限元仿真应用于道路结构的分析受材料参数与边界条件等因素影响较大，要获得其准确、真实的受力状态，需借助原位监测技术。然而，日益得到推广应用的高性能光纤光栅敏感元件因其传统的封装方式，无法在模量上匹配相对离散的道路结构测试。为此，本文以沥青路面结构为研究对象，提出了一种以纯沥青为光纤光栅外包层、以小粒径沥青混合料为封装层的柔性基体材料光纤光栅封装技术，建立了其变形作用机理的力学模型，从理论角度分析其应变传递机理，给出了相应的误差修正公式，并通过模型试验方式检验该传感器的感知性能及误差修正公式的适用性。研究结果表明：该种柔性原材料封装光纤传感器可用于沥青混合料的监测，且借助应变传递误差修正公式能较好地消除部分因素的影响，间接地保证了沥青路面结构真实变形的高精度还原，为路面结构监测技术的发展起到了积极的推进作用。

Strain Transfer Error Analysis of Flexible Raw-material Packaged FBG Sensor

Since the application of mechanics theory and finite element simulation in pavement is confined for the material parameters and boundary conditions, in-situ monitoring technology is thus adopted to obtain the accurate and practical mechanical state. However,the widely used fiber Bragg grating( FBG) with high performance limited to the traditional packaging techniques cannot match the Young’s modulus of discrete pavement structure,which influ-ences the monitoring. Therefore,a flexible raw-material packaged sensor is developed to monitor the strain of asphalt pavement,which regards pure asphalt as the cladding of FBG and small-size asphalt mixture as the protective layer. Corresponding mechanical model is established to explain the deformation-effect mechanism and the strain transfer mechanism is analyzed in theory to offer related error modification formula. Laboratory experiment is carried out to investigate the behavior of the developed FBG sensor and the feasibility of the proposed strain transfer error modifi-cation formula. Research results illustrate that the flexible raw-material packaged FBG sensor is available for the strain detection of asphalt concrete,and the proposed error modification formula can greatly eliminate a part of influ-ence,which indirectly guarantees the high precision revivification of practical strain of asphalt pavements and plays an active role in promoting the development of asphalt pavement health monitoring.