• Structural Engineering and Mechanics
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• v.39 no.3
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• pp.383-398
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• 2011

This paper investigates the nonlinear analysis of concrete-filled steel composite columns subjected to axial loading to predict the ultimate load capacity and behaviour of the columns. Finite element software LUSAS is used to conduct the nonlinear analyses. The accuracy of the finite element modelling is verified by comparing the result with the corresponding experimental result reported by other researchers. Nonlinear analyses are done to study and develop different shapes and number of cold-formed steel sheeting stiffeners with various thicknesses of cold-formed steel sheets. Effects of the parameters on the ultimate axial load capacity and ductility of the concrete-filled steel composite columns are examined. Effects of variables such as concrete compressive strength $f_c$ and cold-formed steel sheet yield stress $f_{yp}$ on the ultimate axial load capacity of the columns are also investigated. The results are shown in the form of axial load-normalized axial shortening plots. It is concluded from the study that the ultimate axial load capacity and behaviour of the concrete-filled steel composite columns can be accurately predicted by the proposed finite element modelling. Results in this study demonstrate that the ultimate axial load capacity and ductility of the columns are affected with various thicknesses of steel sheets and different shapes and number of stiffeners. Also, compressive strength $f_c$ of the concrete and yield stress $f_{yp}$ of the cold-formed steel sheet influence the performance of the columns significantly.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.4
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• pp.39-49
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• 1993

In order to present the geometrically nonlinear F.E. formulation of space frames, two beam/column elements including the effects of transverse shear deformation and bending stretching coupling are developed. In the case of the first element (Finite segment method), the tangent stiffness matrices are derived by directly integrating the equilibrium equations, whereas in the case of the second element (Finite element method) elastic and geometric stiffness matrices are calculated by using the hermitian polynomials including shear deformation effect as the shape function. Both elements possess the usual twelve degrees of freedom. Also, the bowing function including shear deformation effects is obtained in order to account for the effect of shortening of member chord length due to the bending and torsional behavior. Numerical results are presented for the selected test problems which demonstrate that both elements represent reliable and highly accurate tools.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2008.11a
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• pp.93-98
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• 2008

Haeundae Doosan We've The Zenith project is adjacent to Suyoung-bay, now it is in the process of excavation and foundation work. The main use of the tower is residence which height is 300m and 80 floor, the highest residential reinforced concrete building through the Orient. It is comprised of 3 high- rised buildings and 1 low-rised building, the basement is 230m wide and 200m length sized mass structure. The lateral resistance system is acted effectively against the lateral load and satisfactorily against the wind vibration by the 4 direction extension of the center core wall($700{\sim}800mm$ thickness) and reinforced concrete column set around the slab. Flat-plate slab system(250mm thickness) is adjusted for the slab system and it enables effective work process and shortening the working term by minimizing the ceiling height and not needing to install perimeter beam and drop panel. The strength and serviceability of the structure is able to be monitored and estimated constantly through the health monitoring system during the construction and after the construction.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.3
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• pp.211-221
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• 2009

With recent trends of super-tallness, atypical plan shapes and zoning constructions in high-rise buildings, a structural stability of the building under construction is arising as a key issue for design and construction plan. To ensure the structural stability under construction, the differential column shortening of vertical members, the lateral displacement of tower frames, and differential settlement of raft foundation by unbalanced distributions of a tower self-weight before the completion of a lateral load resisting system should be checked by construction sequence analysis, which should be performed by systematic combinations with structural health monitoring, construction compensation program, and construction panning. This paper presents the scheme of zone-based construction sequence analysis by using the existing commercial analysis program, to check the stability of high-rise building under construction. This scheme is applied to 3-dimensional structural analysis for a real high-rise building under construction. The analysis includes real construction zoning plans and schedules as well as creep and shrinkage effects and time-dependent properties of concrete. The simplified construction sequence and assumed material properties were continuously updated with the change on construction schedule and correlations with in-situ measurement data.