Finite Element Modelling of Concrete-Encased Steel Columns Subjected to Eccentric Loadings

  • Worakarn Anuntasena Chulalongkorn University
  • Akhrawat Lenwari Chulalongkorn University
  • Thaksin Thepchatri Chulalongkorn University
Keywords: concrete-encased steel column, 3D finite element analysis, concrete confinement, strength interaction diagram

Abstract

This paper presents the 3D finite element (FE) analysis of the concrete-encased steel (CES) columns subjected to concentric or eccentric loadings. A new simplified technique of FE modelling that incorporates the concrete confinement behavior of the composite columns is proposed. This technique eliminates the need of predefining zones and constitutive properties of the confined concrete. After validated with past experimental data, the FE analysis is conducted to construct the strength interaction diagrams of the short CES columns. The effects of material properties including the compressive strength of concrete and yield strength of structural steel on the strength interaction diagrams of CES columns are numerically investigated. The FE results show that the concrete strength only has a significant effect on the column strength under combined compression and bending (compression phase) of the interaction diagram, while the yield strength of structural steel has a significant effect on both compression and tension phases. A comparison between the strength interaction diagrams predicted by FE analysis and the plastic stress distribution method specified in AISC360-16 “Specification for Structural Steel Buildings” shows that the design provision underestimates the strength of the short CES columns subjected to concentric or eccentric loadings. Such underestimation reduces as the compressive strength of concrete decreases or yield strength of structural steel increases.

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Author Biographies

Worakarn Anuntasena

Composite Structures Research Unit, Department of Civil Engineering, Faculty of Engineering, Chulalongkorn University, Phayathai Rd., Pathumwan, Bangkok 10330, Thailand

Akhrawat Lenwari

Composite Structures Research Unit, Department of Civil Engineering, Faculty of Engineering, Chulalongkorn University, Phayathai Rd., Pathumwan, Bangkok 10330, Thailand

Thaksin Thepchatri

Composite Structures Research Unit, Department of Civil Engineering, Faculty of Engineering, Chulalongkorn University, Phayathai Rd., Pathumwan, Bangkok 10330, Thailand

Published In
Vol 23 No 6, Nov 30, 2019
How to Cite
[1]
W. Anuntasena, A. Lenwari, and T. Thepchatri, “Finite Element Modelling of Concrete-Encased Steel Columns Subjected to Eccentric Loadings”, Eng. J., vol. 23, no. 6, pp. 299-310, Nov. 2019.