Numerical Approach for a Partial CFST Column using an Improved Bond-Slip Model

Ju-young Hwang; Hyo-Gyoung Kwak

doi:10.7734/COSEIK.2020.33.3.153

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2020 Vol.33, Issue 3 Preview Page Next Page

Research Paper

Numerical Approach for a Partial CFST Column using an Improved Bond-Slip Model 개선된 부착슬립 모델을 적용한 부분 CFST 기둥의 수치해석

30 June 2020. pp. 153-158

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Abstract

In this study, a numerical approach for evaluating the resisting capacity of a partial concrete-filled steel tube (CFST) column is introduced. By strengthening the plastic hinge part of a traditional reinforced concrete column with a steel tube, a partial CFST shows a similar bending moment capacity as that of a full CFST column but with reduced material cost. To conduct an elaborate numerical analysis of a partial CFST column, an improved bond-slip model is applied to a finite element (FE) model at the interface between the steel tube and in-filled concrete. This numerical model is verified through the results of a double curvature bending-compression test. A parametric study with the proposed numerical model is used to obtain the load moment interaction diagrams for evaluating the resisting capacity based on various dimensions. Finally, the required strengthening length is estimated for each degree of thickness of the steel tube, and the failure mechanism of the partial CFST column based on the dimensions of the steel tube are identified.

Keywords

bond-slip effect

partial CFST column

double curvature bending-compression test

P-M interaction diagram

본 논문에서는 부분 CFST (concrete-filled steel tube) 기둥에 대한 수치해석적 저항력 평가 방법에 대해 소개하고 있다. 기존 RC (reinforced concrete) 기둥에서 소성힌지가 발생할 것으로 예상되는 부분을 강관으로 보강함으로써 완전 CFST 기둥보다는 적은 재료를 사용하여 비슷한 휨 모멘트 저항력을 가지는 부분 CFST 기둥의 디자인 컨셉을 제시하였다. 부분 CFST 기둥에서 외부 강관과 내부 콘크리트 사이의 계면에서 거동을 수치해석적으로 모사하기 위해 개선된 부착슬립모델을 적용한 유한요소모델을 구축하고, 이중곡률 휨-압축시험결과와 비교를 통해 타당성을 검증하였다. 검증된 수치모델을 바탕으로 매개변수 연구를 통해서 P-M 상관도를 그려 단면 조건에 따른 최대 저항력을 평가하였다. 또한, 강관 두께별로 필요 보강길이를 산출하고, 보강 조건에 따른 부분 CFST 기둥에서의 파괴메커니즘을 분석하였다.

키워드

부착슬립효과

부분 CFST 기둥

이중곡률 휨-압축 시험

P-M 상관도

References

ABAQUS (2014) Abaqus Analysis User's Manual version 6.14, Dassault Systèmes Simulia Corp., Providence, RI, USA.

American Institute of Steel Construction (AISC) (2012) Specifications for Structural Steel Buildings (ANSI/AISC 360-10), Chicago.

Choi, I.R., Chung, K.S., Kim, C.S. (2017) Experimental Study on Rectangular CFT Columns with Different Steel Grades and Thicknesses, J. Constr. Steel Res., 130, pp.109~119.

10.1016/j.jcsr.2016.12.013

Goto, Y., Kumar, G.P., Kawanishi, N. (2010) Nonlinear Finite- Element Analysis for Hysteretic Behavior of Thin-Walled Circular Steel Columns with In-Filled Concrete, J. Struct. Eng., 136, pp.1413~1422.

10.1061/(ASCE)ST.1943-541X.0000240

Hu, H.T., Su, F.C., Elchalakani, M. (2010) Finite Element Analysis of CFT Columns Subjected to Pure Bending Moment, Steel & Composite Structures, October, 10(5), pp.415~428.

10.12989/scs.2010.10.5.415

Hwang, J.Y., Kwak, H.G., Kwon, Y. (2018) A Numerical Model for Considering the Bond-Slip Effect in Axially Loaded Circular Concrete-Filled Tube Columns, Adv. Struct. Eng., 21(12), pp.1923~1935.

10.1177/1369433218759779

Kwon, S.H., Kim, Y.Y., Kim, J.K. (2005) Long-term Behaviour under Axial Service Loads of Circular Columns Made from Concrete Filled Steel Tubes, Mag. Concrete Res., 57, pp.87~99.

10.1680/macr.57.2.87.58702

Kwon, Y., Kwak, H.G., Hwang, J.Y., Kim, J.K., Kim, J.M. (2015) An Improved Bond Slip Model of CFT Columns for Nonlinear Finite Element Analysis, J. Comput. Struct. Eng. Inst. Korea, 28(2), pp.213~220.

10.7734/COSEIK.2015.28.2.213

Moon, J., Lee, H.-E. (2014) Experimental Evaluation of Flexural behavior of Partially Embedded Circular CFST Pier-to-Coping Connection, J. Railway Conf. 2014, pp.1387~1392.

Yin, X., Lu, X. (2010) Study on Push-out Test and Bond Stress-slip Relationship of Circular Concrete Filled Steel Tube, Steel Compos. Struct., 10, pp.317~329.

10.12989/scs.2010.10.4.317

Information

Publisher :Computational Structural Engineering Institute of Korea
Publisher(Ko) :한국전산구조공학회
Journal Title :Journal of the Computational Structural Engineering Institute of Korea
Journal Title(Ko) :한국전산구조공학회 논문집
Volume : 33
No :3
Pages :153-158
Received Date : 2020-02-17
Revised Date : 2020-02-25
Accepted Date : 2020-02-26
DOI :https://doi.org/10.7734/COSEIK.2020.33.3.153

Journal of the Computational Structural Engineering Institute of Korea ISSN:1229-3059(Print) 2287-2302(Online) 한국전산구조공학회 논문집

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