Global buckling behavior of blade stiffened compression flange of FRP box-beams

Light weight superstructure is beneficial for bridges in remote areas and in emergency erection. In such weight sensitive applications, combination of fiber reinforced polymer (FRP) as a material and stiffened box-beams as a structural system have great scope. This combination offers various advantageous but being a thin walled structure, their designs are often governed by buckling criteria. In the case of longitudinally stiffened box-beams, stiffened panels predominately loss their stability either by local or global buckling mode. In this paper, global buckling behavior of the stiffened panel is studied as part of the box-beam to take care the effect of realistic state of stress in the compression flange and effect of boundary condition at web-flange junctions. A parametric study by varying the sectional geometry and fiber orientation is carried out by using ANSYS software. The accuracy of the FE models was ensured by verifying them against the available results provided in the literature. With the help of developed database, the influential parameters (i.e. D-1/D-2, (EA)(fs)/(EA)(fp), alpha(sf), C-EIw and beta(sf)) affecting the global bucklings are identified. The significance on buckling stress is shown with the help of generic curves and bar charts which will be helpful to the designers at the preliminary stage.