Geometrically nonlinear analysis of hybrid beam–column with several encased steel profiles in partial interaction

International audience; This article presents a new co-rotational finite element for the large displacement analysis of hybrid steel–concrete beam/column with several encased steel profiles. The advantage of using the co-rotational approach is that the geometrical linear finite element formulation can be reused and automatically be transformed into geometrical nonlinear formulation. The exact stiffness matrix derived from the analytical solution of the governing equations for hybrid beam with longitudinal partial interaction is used for the local formulation. As a result, internal nodes used to avoid curvature locking encountered in low order polynomial finite elements are not required. Finally, five numerical applications are presented in order to illustrate the performance of the proposed formulation.