基于敏感膜的光纤光栅钢筋锈蚀传感机理及性能优化研究

Corrosion of steel in structures is a major cause of structural degradations. Corrosion detection and monitoring are thus important for evaluation of structural service conditions. .The fibre Bragg grating (FBG) sensors are a group of advanced, non-destructive, real-time and efficient optic sensors for structural evaluations. They have been developed for monitoring the structural and material conditions and are applied in various large-scale projects. .A novel FBG based sensor for steel corrosion detection and monitoring is developed for supplying an effective and reliable solution. The sensor can be used to establish distributed sensing system for non-destructive and real-time monitoring of steel corrosion status, and to provide alert signals of severe steel corrosion. In this project, the mechanism and the improvement of the sensing method will be investigated. The sensitive materials with different corrosion rate will be designed. Magnetron sputtering technique is improved for iron-based film deposition on FBG segment. The mechanism of the sensor is investigated by the expansion model and the mechanics model of the sensitive films. Finally, the relation model of the film corrosion and FBG wavelength is built based on the data from systematic-designed experiments. Owing to the achievement of this project, the FBG based sensor for steel corrosion sensing method is optimized for application in field.

混凝土结构中的钢筋锈蚀会导致构件承载力下降和延性的降低，并引起混凝土剥落，影响整个结构的安全性。实时在线监测钢筋的锈蚀状态为结构评估和维护措施决策提供关键数据。基于敏感膜的光纤光栅钢筋锈蚀传感技术结合了光栅的应变敏感特性和锈蚀产物的体积膨胀特性，充分发挥了光栅传感技术的长期可靠性和分布式传感等优势。本课题针对基于敏感膜的光纤光栅钢筋锈蚀传感技术进行传感机理和性能优化研究，拟通过敏感膜材料的组分设计，得到具有不同锈蚀速率的敏感膜材料，制定相应的制备方案；研究敏感薄膜材料在锈蚀条件下的膨胀行为，探求敏感膜锈蚀膨胀与光栅协同作用关系，构建敏感膜的锈蚀膨胀描述模型和力学模型；通过实验和理论分析，确立敏感膜光栅传感器输出与钢筋锈蚀状态之间的关系数据库和模型，基于该模型进一步优化敏感膜的设计，提高传感器的综合性能。课题研究成果将有效完善基于敏感膜的光栅钢筋锈蚀传感方法，并为其实用化提供理论指导。

钢筋锈蚀的早期监测可有效预防安全事故，降低生命财产受损的风险。如何实现钢筋锈蚀的长期、可靠和准确监测是锈蚀监测中的重要课题。本项目提出了一种光纤光栅锈蚀传感器。本项目计划对光栅锈蚀传感器进行了制备、结构设计的优化研究，通过收集和分析锈蚀状态进程中的各方面数据，建立传感器对锈蚀状态评估的关系，提高锈蚀监测的准确性。本项目实际执行期间，在完成上述研究任务的同时，重点研究了制备方案优化和传感器结构改进，采用两种制备方案得到两种锈蚀敏感膜，比较了两种传感器结构的传感行为，利用多种加速锈蚀实验方案，收集了用于评估锈蚀进程的各项数据，成功地建立了光纤传感器输出与锈蚀状态之间的联系。此外，本项目还创新地提出利用改性的高分子涂敷层提高传感灵敏度的方法，探讨了偏振型锈蚀传感器的理论和技术可行性。项目的重要结果包括传感器敏感膜制备方法和参数，传感器输出数据和锈蚀状态之间的关系，显著提高涂敷层敏感性的方法，偏振型锈蚀传感器工作原理和传感特点。项目执行期间成功发表多篇SCI和EI检索文章，取得了多项相关专利授权，为未来研究工作奠定了良好的基础。