EXPERIMENTAL STUDY ON BUCKLING RESISTANCE TECHNIQUE OF STEEL MEMBERS STRENGTHENED USING FRP

Fiber-reinforced polymer (FRP) strengthening technique to improve buckling resistance of steel members is presented in concept and experimental demonstration. The conceptual design of this method is introduced through the preliminary experiments on three specimens. Then, another 14 specimens are tested under axially compressive loading, by which the compressive behavior and the strengthening effects are investigated considering different design parameters and configuration, including the slenderness ratio, the confinement detail, the filled materials and the end connection. The strengthening effects are analyzed by the comparison of both theoretical and test results, which show that the overall buckling failure of steel members can be prevented by FRP strengthening and the ultimate loading capacity and deformation capacity of steel members are enhanced considerably. The maximum load-bearing capacity of strengthened members is 2.86 times of the nonstrengthened ones, and the failure maintains a ductile behavior. In addition, the load-bearing capacity of the members strengthened in this way is compared with the Euler loads of the original steel member and the composite member.