NUMERICAL INVESTIGATION ON THE SEISMIC BEHAVIOUR OF REINFORCED CONCRETE EXTERIOR WIDE BEAM-COLUMN CONNECTIONS WITH ECCENTRICITY

During past decades, the use of wide beam-column RC system as a way to optimize the cost of construction has been proposed. In this context, many researchers have studied seismic behavior of wide-beam column connections. However, no researches have been carried out on the behavior of these joints when the axis of wide-beam and that of column have eccentricity relative to each other. In order to illustrate the structural performance of reinforced concrete wide beam-column connection, an experimental research was carried out to illustrate the behaviour of exterior RC wide beam-column connections when subjected to quasi-static cyclic loading. The specimen was full-scale connection. This specimen was designed in accordance with ACI-318 version 2008 and controlled by ACI-318 version 2014. Experimental results indicated that the hysteresis response of the wide beam was likely exhibited remarkable enhancement compared to that of conventional beam and the total energy dissipating capacity of a wide beam---column connection was higher than the conventional joint. In this study, exterior wide beam-column connections were simulated using nonlinear finite elements. Concrete material was simulated using plastic-damage model integrated into ABAQUS software. The lateral load- drift curves are in good agreement with experimental results. After validation of the numerical models, the effects of various parameters including eccentricity, beam to column width ratio and column axial load have been investigated for the wide beam-column connections of six buildings containing three 5 stories, two 6 stories and one 7 stories designed based on the Iranian Building code of practice part-9 and Iranian standard 2800 for seismic design. The results indicate that the torsion induced by the eccentricity of axis of wide beam relative to axis of column, must be included in the design of wide beam-column connections. Furthermore, increasing eccentricity causes a drop in lateral load-drif. In the case of maximum eccentricity and 5\% drift the drop embarks on 12.8\%. In addition, by increasing the ratio of beam-to-column width, eccentricity is more destructive.