Prediction the Shear Strength for FRP Shear Strengthened RC Beams Based on Optimised Truss Models

This paper presents the analytical optimised truss model based on the principle of the minimum total strain energy theorem. The model was validated against 90 experimental data collected from the literature. The predicted shear strength in the analysis showed a very satisfactory correlation with the test results, with the average experimental/analytical failure load ratio of 1.09 and the coefficient of variation (C.O.V) of 14.1%. Furthermore, a comparison between the accuracy of the proposed model and the current design guidelines was also demonstrated in this study. It was observed that the optimised truss model led to be more viable than the standard 45-deg truss model in the design guidelines. A large dispersion of the results was found in ACI 440 with the C.O.V as far as 31.4%; whilst the TR 55 and fib 14 showed no significant difference with the C.O.V of 29.3% and 21.5%, respectively.