Numerical analysis of continuous deep beams reinforced with polymer bars

In this study, a 2D finite element analysis was performed utilising the ABAQUS/Explicit method to present a model capable of estimating the response of GFRP RC continuous deep beams. Four GFRP reinforced specimens were experimentally tested, and then employed to validate the proposed FE model. Two different section depths (300 and 600 mm) and two web reinforcement ratios (0 and 0.4%) were employed. All other variables, namely longitudinal reinforcement, compressive strength, beams width, shear span-to-overall depth ratio (a/h) and compressive strength were kept constant. Based on pullout tests performed on GFRP bars conducted in this study, the interface between longitudinal reinforcement and surrounding concrete was modeled employing ABAQUS cohesive element (COH2D4) tool. To assess the validity of the assumption established by some related studies, perfect bonding between the longitudinal reinforcement and concrete was also simulated. To achieve a reasonable agreement with the test results, a sensitivity analysis was used to determine the best mesh size as well as concrete model variables. The suitability and capability of the developed FE model was demonstrated by comparing the predicted outcomes with those measured experimentally. Model validation showed a reasonable agreement with the measured data regarding total failure load, failure mode and loading-deflection responses. The perfect bond model overestimated the predicted results in respect of failure load and stiffness behaviour, while the cohesive element model was more suitable to reflect the behaviour of those specimens.