Improved theoretical solution for interfacial stresses in concrete beams strengthened with FRP plate

Abstract

In this paper, an improved theoretical interfacial stress analysis is presented for simply supported concrete beam bonded with a FRP plate. The adherend shear deformations have been included in the present theoretical analyses by assuming a linear shear stress through the thickness of the adherends, while all existing solutions neglect this effect. Remarkable effect of shear deformations of adherends has been noted in the results. Indeed, the resulting interfacial stresses concentrations are considerably smaller than those obtained by other models which neglect adherent shear deformations. It is shown that both the normal and shear stresses at the interface are influenced by the material and geometry parameters of the composite beam. This research is helpful for the understanding on mechanical behavior of the interface and design of the FRP-RC hybrid structures.

An improved adhesively bonded bi-material beam model for plated beams

“…As shown in Fig. 3, the real deformed cross-section of each adherend is nonlinear, which deviates from the linear one assumed by Tsai et al [14] and Abdelouahed [1]. In this respect, the present study expects to have higher accuracy and produces equivalent results as in high-order theories.…”

“…As a verification of the present solution, comparisons of the present model with typical existing analytical solutions [3,10,15,1] are made. As an example, a reinforced concrete (RC) beam strengthened by a thin carbon fiber-reinforced plastic (CFRP) composite plate studied by Smith and Teng [10], Wang [15], and Abdelouahed [1] is investigated.…”

“…Considering the high stress concentrations near the ends of the strengthening plate, an assumption of linear shear stress distributions through the thickness of the adherends was adopted by Tsai et al [14] and Abdelouahed [1] to obtain the interface stresses. Besides incorporating the effect of interface shear stress on the deformation of adherends 1 and 2, the additional contribution from the interface normal stresses are also taken into account in this study by introducing two interface compliances which were first used by Suhir [11] and later applied to the interface deformable bi-layer beam model developed by Qiao and Wang [4].…”

“…Smith and Teng [10] conducted a comprehensive review of the available models and presented a new solution, which accounted for terms neglected in the aforementioned solutions and was suitable for more widely applicable loading conditions. Based on the solution of Tsai et al [14], Abdelouahed [1] proposed a solution by incorporating the effects of interface shear stress on deformation in adherends, which were ignored by Smith and Teng [10] when they uncoupled a coupled governing equation. The solutions by Smith and Teng [10] and Abdelouahed [1] were comparable but more accurate than the early models.…”

“…Based on the solution of Tsai et al [14], Abdelouahed [1] proposed a solution by incorporating the effects of interface shear stress on deformation in adherends, which were ignored by Smith and Teng [10] when they uncoupled a coupled governing equation. The solutions by Smith and Teng [10] and Abdelouahed [1] were comparable but more accurate than the early models. However, the linear relationship between the interface shear stresses and shear deformation of adherends was adopted, which deviates from the reality because the high stress concentration exists in the adhesive layer at the plate ends.…”