Finite element model for analysis of the spatial interfacial debonding of FRP from concrete

The debonding of the FRP plate from concrete and crack-propagation processes are complex and the current research studies regarding this debonding mechanism are insufficient and not comprehensive. This work proposes a plane stress model along with equal width and different width FRP to concrete models to simulate the debonding and crack-propagation processes are presented. The longitudinal and horizontal stress distributions were analysed and the FRP to concrete width effect and FRP thickness parameters were also studied by means of the proposed three-dimensional finite element model. The results show that the different width 3D model is optimal for analysing the spatial interfacial debonding of FRP from concrete. The concrete surface horizontal stress distribution along the length of the concrete substrate could judge the effective bond length. Both the normal stress and shear stress are mainly divided into the following two small central stress regions under the PRP plate: a high stress gradient region near the FRP plate edge and a stress-free region near the concrete edge. The debonding strength and the stiffness of the bonding interface increase with the width of the FRP plate and the FRP plate thickness. The stress range and magnitude are strongly dependent on the width of the FRP plate. Debonding begins at the FRP plate edge; the thicker FRP plate more easily exhibits debonding.