【作者】 李剑芝；

【导师】 杜彦良；

【作者基本信息】 北京交通大学 ， 车辆工程， 2010， 博士

【摘要】 针对传统钢索存在的易腐蚀、非线性效应以及易振动问题,提出了基于光纤光栅传感的智能纤维增强复合材料斜拉索。它是未来斜拉索的发展趋势和国内外的研究热点,具有重要的学术意义和工程应用价值。本文对纤维增强复合材料斜拉索的受力特性进行了分析,提出智能纤维增强复合材料斜拉索丝的设计目标,并围绕基于光纤光栅传感的智能纤维增强复合材料斜拉索丝的关键技术,进行了深入的理论分析、数值分析和试验研究,主要研究内容有:1)针对光栅存在的温度-应变缠绕问题进行深入的理论与试验研究。首先对温度-应变缠绕问题进行深入的理论分析;然后建立基于材料热应力的温度补偿机制,进行结构设计与分析,并制作具有温度自补偿功能的光纤光栅应变传感器;最后进行了相关的考核试验。理论分析与试验研究结果表明:制作的传感器不仅能够实现温度自补偿的功能,而且还具有应变增敏作用,提高了光栅传感器的应变测试精度。2)进行光栅应变传感器的微型化技术的研究。例如封装材料的选择、封装结构的设计、封装工艺的研究等。研究结果表明:确立了微型化光栅应变传感器的封装工艺;并且设计制作的微型传感器部分实现了温度自补偿的功能,而且具有一定的应变增敏效果,为在线埋入复合材料奠定了基础。3)采用原位复合的思想,进行基于光纤光栅传感的智能混杂纤维增强复合材料斜拉索丝的研究。因此对光栅埋入的界面复合模型、复合工艺及特性考核进行一系列的理论、试验研究。试验结果表明:光栅传感器与纤维增强复合材料界面不会剥离,能够实现外部应力的有效传递;通过材料性能测试,纤维增强复合材料满足拉索力学性能要求;纤维增强复合材料的阻尼远远优于钢制拉索材料的阻尼:并最终确立了混杂纤维增强复合材料智能拉索丝的成型工艺,该工艺制作的混杂纤维增强复合材料智能拉索丝,既能满足拉索的力学性能要求,又能保证光栅传感器在线复合的成活率。更多还原

【Abstract】 Steel stayed cable has some disadvantages, such as easy corrosion, nonlinear effect and prone to vibration, which pose a great threat to the bridge. Thus optical fibre Bragg gratings sensing technology-based FRP smart stayed cables was proposed, which is the development trend of the future cables and the focus at home and abroad. Therefore this study has theoretical and engineering significance..Based on the mechanical and dynamic analysis of FRP stayed cables, the design goal is proposed. And several key problems on optical fibre Bragg gratings sensing technology-based FRP smart stayed cables bar are investigated in this dissertation. The main contents are as follows:1) Thorough research on temperature-strain entangling of FBG is done and experimented. Firstly, the theory of temperature-strain entangling is thoroughly analyzed. Secondly, based on these analyses, the temperature-compensating mechanism was proposed. At last, the sensor was designed, made and verified. The results show the sensor made has not only the temperature-compensating function but also the strain-enhancing function.2) The micro-technology of the FBG strain was investigated, which include the selection of packaging materials, design of the structure and packaging process. The results show that the sensor made partly realizes the temperature-compensating function, but has a strain-enhancing function.3) Optical fibre Bragg gratings sensing technology-based FRP smart stayed cables was investigated by in-situ composite theory. Thus several key problems, such as the interface-composite model, composite process of the FRP bar and performance examination, were studied. The numerical and experimental results show that the debonding of the FBG-FRP interface do not occur. At the same time, their performance in tensile, bond and flexural tests is examined to assess the effectiveness of these smart FRP bars and can satisfied the requirements of the stayed cables. The regularity of the low-frequency damping performance of FRP was attained in the working range of stayed cable. The pultrusion technology was established to modify to incorporate FBG sensors within FRP bars to provide smart FRP bar for achieving the dual purpose of structural strengthening and strain monitoring.更多还原