IMPROVEMENT OF LOCAL BUCKLING CAPACITY OF STEEL BEAMS THROUGH BONDING GFRP PLATES

摘要

The application of glass fiber reinforced polymers (GFRP) composites is used extensively to strengthen and/or to rehabilitate civil infrastructures. Research studies in steel structures retrofitted with GFRP are done mainly improving their flexural capacities. The current study focuses on the application of GFRP in enhancing local buckling capacity of l-shaped steel beams. The study is conducted numerically using a finite element model developed in-house. In the numerical model, consistent shell elements are used to simulate both the flanges and web of the steel beam as well as the GFRP plate. The interface between the steel and the GFRP plate is simulated using a set of continuous linear spring systems representing both the shear and peeling stiffness of the adhesive. The mechanical properties of the adhesive used in the finite element analysis are based on actual values determined experimentally from the previous studies. The numerical model is used to assess the effectiveness of using GFRP plates in enhancing the local buckling capacity of l-shaped steel beams. From the analyses, it shows that both the buckling load and deflection at failure of retrofitted beams increase due to addition of GFRP plates. Moreover, the load improvement ratio is higher for the slender beams than that of the plastic steel beams.