Finite Element Analysis Of Interfacial Stresses Of Cracked Steel Structures Strengthed With CFRP Plate

When carbon fiber reinforced polymer (CFRP) was used in the notched steel structure reinforcement projects, leading to structural failure due to the degradation of the adhesive layer. According to the tese model of notched steel beams strengthed with CFRP plate and the test model of notched steel plates strengthed with CFRP plate, the finite element model has proposed in ABAQUS. In the proposed finite element model, a mixed-mode cohesive law is employed to depict adhesive behavior. And adhesive of the finite element model simulated based on cohesive element in ABAQUS. Comparions of the capacity and interfacial crack propagation law of experimental and finite element model. And a parametric study on finite element model of notched steel beams strengthed with CFRP plate and notched steel plates strengthed with CFRP plate.The main contents and conclusions can be seen as follow:Firstly, the finite element model of notched steel beams strengthed with CFRP plate is proposed. The good agreement between the load-deflection curve and the longitudinal strain distribution in the CFRP plate of experimental and finite element model. The results show that the failure mode of the finite element model of notched steel beams strengthed with CFRP plate is first generated the interfacial crack at the notch position, and to extend the plate end. It is consistent with the test phenomena. Debonding load deviation of finite element results and the test results is small. The maximum deviation of the ultimate load is less than 6.0%. It shows that the finite element model has good accuracy, the result is reliable.Secondly, for notched steel beams strengthed with CFRP plate, the important ones are the crack depth, CFRP elastic modulus and the thickness of CFRP. These parameters were studied using the the finite element model of notched steel beams strengthed with CFRP plate. The results indicate crack depth have a great impact on the bearing capacity of reinforcement beams. When the increase in crack depth, interfacial stresses of notch decreased relatively fast. And the ultimate load and ultimate deflection decreased. When the increase in CFRP elastic modulus and the thickness of CFRP, interfacial stresses of notch decreased slowly. And the debonding load and ultimate load increase but reduced ductility.Thirdly, the finite element model of notched steel plates strengthed with CFRP plate is proposed. The good agreement between the load-strain curve of reinforcement form A and reinforcement form B in the CFRP plate of experimentaland finite element model. It shows that the finite element model has good accuracy. High ultimate load and good ductility of reinforcement form A shows that the good reinforcement effect. The results show that the failure mode of the finite element model of reinforcement form A and reinforcement form B is first generated the interfacial crack at the plate end, and to extend the notch position. It is consistent with the test phenomena.Fourthly, for reinforcement form A and reinforcement form B, the important ones are CFRP elastic modulus and the thickness of CFRP. These parameters were studied using the the finite element model of notched steel plates strengthed with CFRP plate. The results showed that increase CFRP elastic modulus and the thickness of CFRP can significantly increase the stiffness of reinforcement form A and reinforcement form B. When the increase in CFRP elastic modulus and the thickness of CFRP, the ultimate load of reinforcement form A decrease. But it has no effect on debonding load and interfacial stresses of reinforcement form A. And it also has no effect on debonding load and ultimate load of reinforcement form B. When the increase in CFRP elastic modulus and the thickness of CFRP, the adhesive layer of reinforcement form B softens earlier...