Experimental and nonlinear finite element studies of RC beams strengthened with FRP plates

This paper presents a joint experimental–analytical investigation aimed at studying the brittle failure modes of RC members strengthened in flexure by FRP plates. Both midspan and plate end failure modes are studied. The finite element analyses are based on nonlinear fracture mechanics. The model considered the actual crack pattern observed in the tests by using a smeared and an interface crack model. This paper shows how concrete cracking, adhesive behavior, plate length, width and stiffness affect the failure mechanisms. The numerical and experimental results show that debonding and concrete cover splitting failure modes occur always by crack propagation inside the concrete.