Development of a new outer sleeve assembly for beam-column connections

With a view to improving the ease of construction, a new type of outer sleeve assembly (OSA) between steel beam and column has been developed. The characteristics of stress distribution and failure modes of the components of twelve OSAs were analysed using a general purpose finite element software ANSYS. The roles of square and H outer sleeves to the structural action of the OSA are described in this paper. The material, geometry and contact nonlinearities of the assembly of the OSA have been identified as the main factors affecting the joint stiffness and bending capacity. Seismic performance of the new OSA is reported using failure modes, hysteresis curves and skeleton curves of different models. Four key parameters, viz., the thickness of the sleeve, the wall thickness of square steel tubular column, the length of square sleeve and the length of H sleeve are shown to significantly affect the monotonic and the hysteretic behaviour of the joint. Based on the superposition principle, a simplified method for calculating the initial stiffness of the OSA is proposed. Using the component method, the flexural capacity of the outer sleeve joint was calculated and analysed. The simulation and theoretical calculation have proved that the simplified calculation method is feasible. The numerical analysis results show that the new OSA beam-column connection joint has good energy dissipation and ductility under low-cycle cyclic loading. The four parameters mentioned above have certain influence on the bearing capacity, energy dissipation and ductility of the joint. •New type of outer sleeve assembly (OSA) between steel beam and column is developed.•Simplified method for calculating the initial stiffness of the OSA is proposed.•Flexural capacity of the outer sleeve joint is calculated and analysed.•New OSA beam-column connection joint has good energy dissipation and ductility.