Unilateral buckling of elastically restrained rectangular mild steel plates

This paper considers the elastic unilateral buckling of rectangular mild st eel plates that are restrained elastically and subjected to bending and axi al actions. A variational formulation of the Ritz method using linear combi nations of harmonic functions for the buckling deformations is used to esta blish an eigenproblem to determine the plate local buckling coefficients. T he motivation for the study is the retrofit of reinforced concrete beams by gluing and then bolting steel plates to the sides of the beam. Such plates , when acting compositely with the concrete beam, are subjected to predomin antly bending and axial actions which may cause unilateral local buckling. Whereas the bolts provide complete restraint against buckling at discrete p oints, the glue may also inhibit local buckling between these nodal points since it acts as a continuous elastic restraint. The influence of the glue stiffness, support conditions and plate proportions on the unilateral buckl ing of such plates are assessed.