基于CFRP自传感的受压结构智能监测研究与应用

Study and application of smart monitoring on compressed structures based on CFRP self-sensing

  • 摘要: 本文探索了基于碳纤维增强聚合物基复合材料(CFRP)智能特性的受压构件健康监测新方法。将CFRP智能带以不同角度黏贴在轴向受压混凝土柱的侧面,研究准静态单调压缩和循环压缩作用下不同偏轴角的智能带的电阻响应特征。结果表明,CFRP智能带在单调加载全过程中的电阻与被监测结构的阶段化变化相关,经历了初期的缓慢变化、中期的快速变化和结构失效时的急剧变化,直至结构失效后电阻部分恢复;循环荷载作用下电阻呈周期性变化,且大部分电阻变化可以恢复,仅有少量不可恢复电阻产生于首次循环加载阶段。此外,偏轴角 \mathrm\;\beta 对电阻响应具有重要影响: \mathrm\;\beta =0°与90°时智能带分别呈现负压阻效应和正压阻效应,而45°偏轴角时智能带分阶段出现不同的压阻效应,且电阻变化幅度相对较小。工程应用实践结果验证了上述CFRP智能带在结构监测中的可行性和有效性。

     

    Abstract: A novel approach to structural health monitoring of compressed structures leveraging the intelligent properties of carbon fiber Reinforced Polymer (CFRP) was investigated. Smart CFRP strips were attached to the side surfaces of the axially compressed concrete column at various angles, and the electrical resistance of these strips under both monotonic and cyclic compression at different off-axial angles were analyzed. The findings reveal that the resistance of smart CFRP strips throughout the entire monotonic loading process correlates with the changes of the monitored structure, undergoing initial gradual changes, rapid changes at middle stage, and a sharp change upon the structural failure. The resistance changes partly reverse after failure. Under cyclic loading, the resistance shows periodic variations, with the resistance changes primarily being reversible, except for a small amount of irreversible resistance that occurs during the first loading cycle. Additionally, the off-axial angle, \mathrm\;\beta , significantly influences the resistance response. At \mathrm\;\beta =0° and \mathrm\;\beta =90°, the smart strips exhibit negative and positive piezoresistive effects, respectively; while at \mathrm\;\beta =45°, they display various piezoresistive effects in different phases, with a smaller change in resistance. The practical application results confirm the applicability and efficiency of the smart CFRP strips in structural monitoring.

     

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