The Finite Element Analysis Of Concrete Beams Strengthened With Near Surface Mounted Cfrp Laminates

Near-surface mounted (NSM) carbon fiber reinforced plastic (CFRP) is emerging as a promising technique for the strengthening of concrete structures. In recent years, NSM has been noticed widely in abroad for its special advantages. The bond mechanism between NSM FRP laminates and concrete are more complex than External Bonded Reinforced (EBR) fiber sheets, which are effected by the FRP category, the type and performance of filling material in the groove, groove size, space between grooves, space from groove to concrete edge, concrete grade, and so on. With the mature development of the finite element computation theory which provides a convenient computing tool for structure reinforcement, it could better simulate the entire stress processes of structure. Thus reduced massive manpower, material resource and financial resource and offered the theory guarantee for structure design and construction.The paper used the combinative method with test and finite element analysis (FEA) to study the characteristics of concrete beam strengthened with NSM CFRP laminates and introduced the FEA models of reinforced concrete, the constitutive relation of steel and concrete, concrete's intensity criterion and crack processing way, selected the reasonable material constitutive relation, element type and established the material parameter. The study compared strains from the FEA results with measured strains from test.The test results indicate that NSM CFRP laminates is more effective than EBR CFRP laminates. The bearing-capacity is increased obviously, the crack is restrained the stiffness is increased; the use of the FRP laminates is more effective by NSM CFRP strengthening. The FEA results agree well with test results, which could show that the FEA can well simulate the concrete beam's bearing and deformation with the reasonable finite element model, material constitutive relation, element type and element division. So the finite element method as a powerful numeric analytic tool plays the vital role in simulating the flexural failure of concrete beam strengthened with NSM CFRP laminates. The NSM CFRP laminates is more effective than EBR CFRP laminates.