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.

Seismic Behavior of Steel Column Base with Slip-Friction Connections

“…For column base friction connections ( Figure 2 [ 17 ]), Borzouie et al [ 17 ] conducted experimental studies on the cyclic performance of column base strong and weak axis aligned asymmetric friction connection, and it was found that the proposed details for base connections with friction connections provide repeatable cycles without strength degradation or any requirements for repair or replacement following an earthquake. Freddi et al [ 18 ] and Dimopoulos et al [ 19 ] also proposed a new type of a sway damage-free steel column base connection and the results of finite element simulation verified the accuracy of the M - θ curve. This kind of connection can effectively avoid yielding of the column base, thus, achieving the objective of damage-free energy dissipation.…”