Nonlinear modeling of beam-column connections and its impact on the global stability of precast concrete structures

Abstract

This study numerically investigates the behavior of semi-rigid beam–column connections in precast concrete structures, considering precast beams and columns, corbels and dowels, combined with a cast-in-place solid slab and continuity reinforcement to resist negative bending moments. Three-dimensional finite element models developed, calibrated against experimental results and including material and interface nonlinearities, were used to obtain moment–rotation curves and to assess secant stiffness and load-carrying capacity, comparing configurations with and without grout at the corbel–beam interface. A parametric study was carried out by varying the continuity reinforcement ratio, the compressive strength of the cast-in-place concrete, and the slab depth, showing that slab depth has the greatest influence on secant stiffness, with more pronounced effects for the ungrouted connection. Finally, equivalent connection stiffnesses were incorporated into a two-dimensional global stability analysis of multi-storey buildings, evaluating the γz coefficient and horizontal displacements. From a global stability standpoint, the LC-N model produced responses very close to those obtained with perfectly rigid connections, whereas the pinned-joint assumption led to more flexible predictions with larger displacements.