Numerical Parametric Study of Fully Encased Composite Columns Subjected to Cyclic Loading

Almoutaz Bellah Alsamawi,Nadir Boumechra,Karim Hamdaoui

doi:10.28991/cej-2022-08-01-04

Abstract

This paper investigates the cyclic behaviour of steel-concrete encased composite columns. By investigating the cover concrete and the steel-concrete coefficient of friction on the behaviour (strength, ductility, stiffness, and energy dissipation) of composite columns subjected to combined axial load and cyclically increasing lateral load to improve the strength and performance of the composite column. Eight of the columns were designed to study the cover concrete effect, and eleven other columns were designed to study the coefficient of friction effect in the dynamic behaviour to the cyclic load. Additionally, in this study, the finite element models created in ANSYS software were verified and calibrated against previously published experimental results (load-displacement curve, load capacity and failure mode). The numerical results obtained from the finite element model indicate that the ductility and the energy dissipated increased by +11.71 and +18.93% receptively by the increase of the cover concrete until reaching the limit of the cover concrete. Beyond this limit, the ductility and the energy decrease by 27.33 and 24.97% receptively. The results also indicate that the ductility and the energy dissipated increased by 12.62 and 7.82% receptively by the increased coefficient of friction until reach 0.6, after that the energy decreases by 4.47%. Doi: 10.28991/CEJ-2022-08-01-04 Full Text: PDF

Highlights

Composite columns have grown more popular in building constructions in recent years, in seismically active areas and to ensure fire safety
The findings show that high-strength concrete columns are more susceptible to fragile failure than normal-strength concrete columns and that high-strength concrete has a favourable energy absorption capacity
With an increase of the cover concrete, the displacement ductility, the energy dissipation and the stiffness increase by 11.71, 18.93 and 50.52% receptively compared with specimen FEC.CC.1

Summary

Introduction

Composite columns have grown more popular in building constructions in recent years, in seismically active areas and to ensure fire safety. This is because they offer the required rigidity to keep the building's lateral drift to an acceptable level while efficiently resisting wind loads and lateral seismic. The addition of structural steel to the centre of a cross-section column increases the column's ductility while allowing it to resist tensile loads such as reinforced bars or structural steel sections. It was found that increasing the stirrup ratio improves seismic behaviour, that cross-shaped steel composite columns perform better seismically than H-shaped steel composite columns, and that the embedded ratio of steel-concrete composite columns can be as minimal as 2.5. Columns with studs can dissipate more energy and deform more, reducing column stiffness degradation

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