Elastic buckling strength for steel plates symmetrically strengthened with glass fiber reinforced polymer plates

A plate finite element formulation is developed for the buckling analysis of steel plates symmetrically strengthened with glass fiber reinforced polymer (GFRP) plates. The solution idealizes the steel and GFRP as Kirchhoff plates while accounting for the shear-flexibility within the adhesive through a postulated zigzag displacement profile. The solution is then used to characterize the elastic buckling strength for steel plates strengthened with GFRP for corroded flanges subjected to compression, and for steel panels subjected to shear. The validity of the present model is assessed through comparisons with three-dimensional and shear deformable shell solutions. The capacity of the strengthened system is found sensitive to GFRP thickness but insensitive to the adhesive shear modulus. A design example is provided to illustrate how CAN-CSA S16-14 provisions for plate girder design can be integrated with the predictions of the present model to characterize the shear capacity of end panels strengthened with GFRP plates.