This paper presents a novel self-sensing steel fiber-reinforced polymer composite bar (SFCB). The SFCB combines damage control, self-sensing, and structural reinforcement functions using distributed fiber optic sensing (DFOS) technology. By combining DFOS strains with theoretical and numerical models, a multilevel performance method for damage assessment is proposed from the perspectives of safety, suitability, and durability. Stiffness is a metric used to assess the complete service history of the reinforced concrete (RC) structure, which was used to define the damage variables. Initially, a basic correlation is created between the SFCB strain and several performance characteristics, such as moment, curvature, load, deflection, stiffness, and crack breadth, at characteristic points. The threshold values of damage variables for safety, serviceability, and durability were determined based on loading peak, mid-span deflection limits, and crack width limits corresponding to the damage variables. Then, a modified fiber damage model based on DFOS strain data is proposed to improve identification, quantification, and tracking for fiber damage. Finally, the reliability of the proposed theoretical and numerical models was verified by three-point flexural tests of SFCB-RC beams, and the test beams were analyzed using the proposed method. The results show that increasing the reinforcement ratio can lower the threshold at all levels and improve the ability of the flexural beams to control damage. This paper contributes to advancing the intelligence of RC structures and offers valuable insights for the design of intelligent RC structures.

中文翻译：

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使用自感应钢纤维增强聚合物复合筋的钢筋混凝土结构性能评估：理论与试验验证


本文提出了一种新型的自感应钢纤维增强聚合物复合棒 （SFCB）。SFCB 使用分布式光纤传感 （DFOS） 技术将损伤控制、自感应和结构加固功能相结合。通过将 DFOS 应变与理论和数值模型相结合，从安全性、适用性和耐久性的角度提出了一种多层次的损伤评估性能方法。刚度是用于评估钢筋混凝土 （RC） 结构完整服役历史的指标，用于定义损伤变量。最初，SFCB 应变与特征点的几个性能特征（例如力矩、曲率、载荷、挠度、刚度和裂纹宽度）之间建立了基本关联。安全性、正常使用性和耐久性的损伤变量阈值是根据载荷峰值、跨中挠度极限和与损伤变量相对应的裂纹宽度极限确定的。然后，提出了一种基于 DFOS 应变数据的改进纤维损伤模型，以改进纤维损伤的识别、量化和跟踪。最后，通过对 SFCB-RC 梁进行三点弯曲试验，验证了所提理论和数值模型的可靠性，并采用所提方法对试验梁进行了分析。结果表明：提高配筋率可以降低各层次的阈值，提高弯曲梁的损伤控制能力;本文有助于提高 RC 结构的智能化，并为智能 RC 结构的设计提供有价值的见解。