Bond–slip model considering the interface shear stress reversal phenomenon and data dispersion for FRP–concrete interface

• Published in: Engineering fracture mechanics 2022-06, Vol.268, p.108492, Article 108492
• Main Authors: Li, Wen, Huang, Peiyan, Chen, Zhanbiao, Cui, Hangyue, Guo, Xinyan, Wu, Bo
• Format: Article
• Language: English
• Subjects: Bond–slip model; Dispersion; Distribution functions; Empirical analysis; Fluctuation function; Inhomogeneity; Interfaces; Interfacial microcracks; Interfacial shear stresses; Mathematical models; Microcracks; Shear stress; Shear stress reversal phenomenon; Slip; Specimen preparation
• ISSN: 0013-7944; 1873-7315
• DOI: 10.1016/j.engfracmech.2022.108492

•The proposed model reflects the shear stress reversal phenomenon and data dispersion.•Interfacial cracks are the source of the shear stress reverse and data dispersion.•The shear stress reversal phenomenon and data dispersion are twin phenomena. Influenced by interfacial microcracks, the shear stress reversal phenomenon often exists in the experimental bond–slip curves of FRP–concrete interfaces, but the existing bond–slip models cannot reflect this phenomenon. Through the analysis of previous experimental results, it was found that the fluctuating distribution of the interfacial slip field was the direct cause of the shear stress reversal phenomenon. Thus, a bond–slip analytical model that can reflect both the shear stress reversal phenomenon and the dispersion of the bond–slip data at the interface was derived theoretically by introducing the fluctuation distribution function into the typical interfacial slip function and the model was verified using experimental data from different scholars. The results showed that the bond–slip analysis model proposed in this study, which does not require the introduction of additional empirical parameters and has a clear physical meaning. This model reveals that both the dispersion of the bond–slip curves and the shear stress reversal phenomenon originate from interfacial microcracks and have little to do with the inhomogeneity of the materials on both sides of the interface, insufficient testing technology, or the lack of specimen preparation technology.