Finite element modelling and parametric analysis of FRP strengthened RC beams under impact load

In this study, a non-linear three-dimensional finite element model was developed to study the impact behaviour of reinforced concrete beams strengthened in shear and/or flexure with carbon-FRP (CFRP) sheets. Concrete damage plasticity model was used for the concrete part, a traction-separation law for the CFRP-concrete interface, and Hashin criteria for rupture in CFRP. Comparisons with experimental data from literature, for various properties, confirmed the accuracy of developed model. A detailed parametric analysis was performed focusing on: the impact location as a ratio (α) from support to mid-span, impact velocity (v); and several geometrical properties related to CFRP technique. Increasing α from 0.26 to 0.79 results in increasing the maximum displacement (Δmax) for both un-strengthened and strengthened beams. CFRP strengthening resulted in decreasing Δmax for different values of α and v and prevented global concrete failure for v = 8.86 m/s. Δmax is also decreased by 13% when a round corner and an arched soffit were used to prepare the beam substrate for bonding the transverse sheets instead of a sharp corner. Furthermore, the paper presents detailed discussions and implications for the above parameters and two additional ones, namely: configuration of transverse sheets (continuous wraps or discontinuous strips) and thickness of CFRP longitudinal sheets. •The response of CFRP strengthened RC beams was numerically investigated.•The impact response of CFRP strengthened RC beams was investigated with wide range of parameters.•The CFRP strengthening technique is effective in improving impact response of RC beams.