Non-linear finite element analysis of composite planar frames with an interlayer slip

A new finite element formulation is presented for the non-linear analysis of two-layer composite planar frames with an interlayer slip. For each layer the geometrically non-linear Reissner’s beam theory is assumed. A small slip between the layers is considered. Non-linear, time-dependent constitutive models for the layers, and a non-linear relationship between the slip and the shear stress at the interface are accounted for. As only a few finite elements are needed to describe a beam or column of a frame with great precision, the new finite element formulation is prefectly suited for practical calculations.