Nonlinear finite element analyses of FRP-strengthened reinforced concrete slabs using a new layered composite plate element

A new layered 4-node, 24-degrees of freedom rectangular composite plate element is developed in this paper for nonlinear finite element analyses of FRP-strengthened RC slabs. The layered approach is used to form an integrated plate element for modelling of concrete, FRP, adhesive layer and steel reinforcement with a perfect bond assumption between each layer. Timoshenko’s composite beam functions are employed to describe the bending behaviour of the layered plate element and shear locking problem is avoided naturally. Geometrical and material nonlinearities are both included in the new plate element. The proposed element is simple and demonstrated to be accurate and efficient for analysis of the structural behaviour of FRP-strengthened RC slabs. Once validated, the new element is also employed to investigate the effects of parameters, including the types of FRPs and strengthening scheme on the structural behaviour of FRP-strengthened RC slabs.