Exact buckling loads of two-layer composite Reissner’s columns with interlayer slip and uplift

The principal purpose of the paper is to present an efficient mathematical model for studying the buckling behaviour of geometrically perfect, elastic Reissner’s two-layer composite columns with interlayer slip and uplift between the layers. The present mathematical model is capable of predicting exact critical buckling loads and corresponding buckling modes. Thus, it is used to study the influence of the transverse interlayer stiffness in combination with the longitudinal interlayer stiffness on critical buckling loads and modes. This effect is proved to be significant. The critical buckling loads calculated by the proposed method can be up to approximately 89% smaller than those where interlayer uplift is neglected.

► Exact buckling model for columns with slip and uplift is derived for the first time.
► Exact elastic buckling loads are calculated.
► Effect of the transverse interlayer stiffness on buckling loads is significant.
► Effect of uplift on buckling loads is slip modulus and boundary conditions dependent.