Distributed optic fiber sensing for a full-scale PC girder strengthened with prestressed PBO sheets
Distributed optic fiber sensing for a full-scale PC girder strengthened with prestressed PBO sheets
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DOI：
10.1016/j.engstruct.2005.11.012
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发表时间：
2006-06
影响因子：
5.5
通讯作者：
Zhishen Wu;Bin Xu;Keiji Hayashi;A. Machida
中科院分区：
文献类型：
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作者：
Zhishen Wu;Bin Xu;Keiji Hayashi;A. Machida
纤维增强聚合物（FRP）已被广泛接受为改造和加强现有基础设施的创新材料。在FRP材料中，聚对苯撑苯并二恶唑（PBO）纤维片材由于具有高强度、高弹性模量和高吸能性能，近年来受到了广泛关注。本研究首先提出一种包括气囊系统及端部锚固系统的PBO预应力加固技术（P-PUT），用于加固足尺预应力混凝土梁。然后，采用基于布里渊光时域偏折（BOTDR）技术的光纤传感系统，对PBO片材的加固效果、加固后PC梁的性能，特别是不同荷载水平下混凝土和PBO片材的压、拉应变分布以及PBO片材与混凝土表面的粘结性能进行了评价。提出并研究了光纤安装的两种粘结方法，即定点粘结法和整体粘结法。最后，提出了一种多项式曲线拟合的方法来处理受噪声污染的现场数据。
Fiber Reinforcement Polymer (FRP) has been widely accepted as an innovative material for renovation and strengthening of existing infrastructures. Among the FRP materials, poly-p-phenylene benzobisoxazole (PBO) fiber sheets attracted great attention in recent years because of the high strength, high Young modulus and high energy absorption capability. In this study, a PBO Prestressing Upgrading Technique (P-PUT) including an air bag system and end anchoring system for the strengthening of a full-scale prestressed concrete girder is proposed at first. Then, for the purpose of evaluating the strengthening efficiency of the PBO sheets, performance of the strengthened PC girder, especially the compressive and tensional strain distribution of concrete and PBO sheet under different load levels and bonding performance of PBO sheets on concrete surface, optic fiber sensing system with a strain/loss analyzer based on the Brillouin Optical Time Domain Deflectometry (BOTDR) technique is employed. Two types of bonding methods for optic fiber installation called the Point Fixed (PF) method and Overall Bonding (OB) method are proposed and investigated. Finally, a kind of polynomial curve fitting method is presented to process the field data contaminated with noise.