Finite Element Studies on Hollow Steel Columns under Multi-directional Cyclic Loads

Abstract

The unprecedented damage to infrastructure, including steel structures, during recent major earthquakes has emphasized the need for a comprehensive understanding of seismic response, which in reality is complex and multi-directional, as opposed to the conventionally assumed uni-directional approach. Hence, a study was initiated to investigate the effects of several types of cyclic multi-directional load histories on the response of tubular steel columns. The main conclusion drawn from experimental work is that, in comparison with uniaxial displacement paths, multi-directional biaxial displacement paths cause more extensive degradation of column stiffness, strength and ductility, and should therefore be incorporated in seismic design considerations. Herein, finite element (FE) modeling of the columns under multi-directional loading is conducted employing ABAQUS FE code in conjunction with the experimental results. To optimize on the program capabilities, the sensitivity of the developed model is appraised with regard to the effect of type of shell element, type of hardening model and mesh refinement, culminating in a check on the applicability of the model in parametric studies and for the formulation of biaxial interaction curves for seismic design. Thus, the significance of FE program as a modern tool for research and design of complex loading conditions and structures is demonstrated.


Journal of Civil Engineering Research and Practice Vol.1(1) 2004: 33-49