Inelastic buckling of two-layer composite columns with non-linear interface compliance

A mathematical model for a slip-buckling problem has been proposed and its exact solution has been found for the analysis of materially inelastic two-layer composite columns with non-linear interface compliance. The mathematical model has been carried out to evaluate exact critical buckling loads. It has been demonstrated mathematically exactly, that exact critical buckling loads are influenced by the initial stiffness, and hence on linear portion of the interface force-slip relationship. Besides, it has been shown that material inelasticity can reduce the critical buckling loads significantly and that the interlayer stiffness has an important effect on the transition between the elastic and inelastic buckling. ► The exact inelastic slip-buckling model of two-layer composite columns with interlayer slip is derived for the first time. ► Exact elastic and inelastic buckling loads are calculated. ► The exact critical buckling loads are influenced by the initial stiffness. ► The interlayer stiffness has a significant effect on the transition between the elastic and inelastic buckling. ► The effect of interlayer thickness on the exact critical loads is boundary conditions dependent.