11.11: Rocking damage‐free steel column base with friction devices: Development of advanced 3D finite element models in Abaqus

ABSTRACT Column bases are critical components of a seismic‐resistant steel building as they transfer gravity and lateral forces to the foundations. This paper focuses on the finite element (FE) modelling of a rocking damage‐free steel column base, which uses post‐tensioned high strength steel bars to achieve self‐centering behavior and friction devices to provide energy dissipation capacity. Contrary to conventional steel column bases, the monotonic and cyclic moment‐rotation behavior of the column base can be easily described using simple analytical equations. An advanced three‐dimensional FE model for the column base is developed in ABAQUS. The techniques used to overcome convergence issues in numerical simulations as well as the constitutive laws for the nonlinear behavior of materials and friction interfaces are described in detail. The FE model provides results that are in very good agreement with the results from the analytical moment‐rotation equations. The FE model results are also used to validate a simplified numerical model in OpenSees. Moreover, the FE model provides results that help to assess the level of stress concentration in critical areas of the column base and to evaluate a step‐by‐step design procedure that ensures damage‐free behavior, self‐centering capability, and adequate energy dissipation capacity.