Comparison of the predictability of the ultimate axial strength of elliptical CFST columns using existing square and circular section-based code formulae

Abstract

The elliptical hollow section has been recently included in the family of the structural steel hollow sections. This type of steel section is also used in the production of concrete-filled steel tubular (CFST) members. For the elliptical CFST compression members, there is no specific design formulation in the current provisions, except the code called “Technical code for concrete-filled tubular structures” prepared by the Ministry of Housing and Urban-Rural Development of the People’s Republic of China. However, the formula proposed by this code for estimating the ultimate strength of the elliptical CFST columns was achieved by modifying the formula for predicting the ultimate strength of the square CFST members. In this context, the objective of this study is to evaluate the applicability of the existing code formulae that were proposed for the axially loaded CFST columns with rectangular or circular sections to that of columns with an elliptical section. To this, a data repository consisting of 97 experimentally tested elliptical CFST columns was compiled. Herein, the main criterion in the selection of the data was the axial loading condition. Thereafter, the prediction performance of these code formulae was assessed in terms of statistical parameters. The results indicated that the code formulae proposed for the circular-sectioned CFST columns have better prediction capability than that suggested for the rectangular sections. Among these design formulae proposed for the CFST columns with a circular section, the formulae recommended by the American Institute of Steel Construction, British Standard Institute, Canadian Standards Association, and Eurocode 4 performed the best prediction capability. These code formulae had the lowest mean absolute percent error values and R-squared values of higher than 0.8.

Keywords

• Code formula
• Concrete-filled steel tubular column
• Elliptical section

Mevcut kare ve dairesel kesit tabanlı kod formüllerini kullanarak eliptik BDÇT kolonlarının nihai eksenel dayanımının tahmin edilebilirliğinin karşılaştırılması

Abstract

Eliptik içi boş profil, yapısal çelik içi boş profiller ailesine son zamanlarda dahil oldu. Bu tip çelik profil, beton dolgulu çelik tüp (BDÇT) elemanların üretiminde de kullanılmaktadır. Eliptik BDÇT basınç elemanları için muayyen bir tasarım formülü, Çin Halk Cumhuriyeti Konut ve Kentsel-Kırsal Kalkınma Bakanlığınca hazırlanan “Beton dolgulu çelik tüp yapılar için teknik kod” adlı kod dışında mevcut hükümlerin kapsamında yer almamaktadır. Ancak, eliptik BDÇT kolonların nihai dayanımının tayini için önerilen bu formül, kare kesitli BDÇT elemanların nihai dayanımının tahmin edilmesinde kullanılan formülün değiştirilmesi ile elde edilmiştir. Bu bağlamda, bu çalışmanın amacı eksenel yüklenmiş dikdörtgen ve dairesel kesitli BDÇT kolonlar için önerilen mevcut kod formüllerinin eliptik kesitli bu tarz kolonlara uygulanabilirliğini değerlendirmektir. Bunun için, 97 tane deneysel olarak test edilen BDÇT kolonundan oluşan bir data havuzu oluşturuldu. Burada, data seçimindeki ana kriter, eksenel yükleme durumuydu. Sonrasında, bu kod formüllerinin tahmin performansı istatistiksek parametreler nezdinde değerlendirildi. Sonuçlar dairesel kesitli BDÇT kolonlar için önerilen kod formüllerinin dikdörtgen kesitli olanlar için önerilenlerden daha iyi tahmin kapasitesine sahip olduğunu gösterdi. Dairesel kesitli BDÇT kolonları için önerilen bu tasarım formülleri arasında ise en iyi tahmin edebilme kapasitesine, Amerikan Çelik Yapı Enstitüsü, İngiliz Standart Enstitüsü, Kanada Standartlar Birliği ve Avrupa Standartları tarafından önerilen formülleri sahipti. Bu kod formülleri en düşük ortalama mutlak yüzde hata değerlerine ve 0.8’den yüksek R-kare değerlerine sahipti.

Keywords

• Kod formülü
• Beton dolgulu çelik tüp
• Eliptik kesit
• Tahmin etme
• Nihai eksenel dayanım
• Ultimate axial strength

References

1. [1] Yang, H., Lam, D., Gardner, L. (2008). Testing and analysis of concrete-filled elliptical hollow sections. Engineering Structures, 30, 3771-3781. https://doi.org/10.1016/j.engstruct.2008.07.004
2. [2] Lam, D., Testo, N. (2008). Structural design of concrete-filled steel elliptical hollow sections. International Conference on Composite Construction in Steel and Concrete, July 20-24, Colorado, USA. https://doi.org/10.1061/41142(396)21
3. [3] Dai, X.H., Lam, D., Jamaluddin, N., Ye, J. (2014). Numerical analysis of slender elliptical concrete filled columns under axial compression. Thin-Walled Structures, 77, 26-35. https://doi.org/10.1016/j.tws.2013.11.015
4. [4] Ren, Q.X., Han, L.H., Lam, D., Li, W. (2014). Tests on elliptical concrete filled steel tubular (CFST) beams and columns. Journal of Constructional Steel Research, 99, 149-160. https://doi.org/10.1016/j.jcsr.2014.03.010
5. [5] Uenaka, K., Kitoh, H., Sonoda, K. (2010). Concrete filled double skin circular stub columns under compression. Thin-Walled Structures, 48, 19-24. https://doi.org/10.1016/j.tws.2009.08.001
6. [6] Jamaluddin, N., Lam, D., Dai, X.H., Ye, J. (2013). An experimental study on elliptical concrete filled columns under axial compression. Journal of Constructional Steel Research, 87, 6-16. https://doi.org/10.1016/j.jcsr.2013.04.002
7. [7] Dai, X., Lam, D. (2010). Numerical modelling of the axial compressive behavior of short concrete-filled elliptical steel columns. Journal of Constructional Steel Research, 66, 931-942. https://doi.org/10.1016/j.jcsr.2010.02.003
8. [8] Uenaka K. (2014) Experimental study on concrete filled elliptical/oval steel tubular stub columns under compression. Thin-Walled Structures, 78, 131-137. https://doi.org/10.1016/j.tws.2014.01.023

9. [9] Kalemi, B. (2016) Numerical modeling and assessment of circular concrete-filled steel tubular members - MSc Thesis, Istituto Universitario di Studi Superiori di Pavia.
10. [10] Zhang, S., Guo, L., Ye, Z., Wang, Y. (2005). Behavior of steel tube and confined high strength concrete for concrete-filled RHS tubes. Advances in Structural Engineering, 8, 101-116. https://doi.org/10.1260/1369433054037976
11. [11] Zhang, S., Guo, L. (2007). Behaviour of high strength concrete-filled slender RHS steel tubes. Advances in Structural Engineering, 10, 337-351. https://doi.org/10.1260/136943307783239381
12. [12] Gardner, L., Ministro, A. (2005). Structural steel oval hollow sections. Structural Engineer, 83, 32–36. https://doi.org/10.18057/IJASC.2005.1.2.3
13. [13] Packer, J.A. (2008). Going elliptical. Modern Steel Construction, 48, 65–67. https://www.aisc.org/globalassets/modern-steel/archives/2008/03/2008v03_going_elliptical.pdf
14. [14] Zhao, X.L., Packer, J.A. (2009). Tests and design of concrete-filled elliptical hollow section stub columns. Thin-Walled Structures, 47, 617-628. https://doi.org/10.1016/j.tws.2008.11.004
15. [15] Liu, F., Wang, Y., Chan, T.M. (2017). Behaviour of concrete-filled cold-formed elliptical hollow sections with varying aspect ratios. Thin-Walled Structures, 110, 47-61. https://doi.org/10.1016/j.tws.2016.10.013
16. [16] Mahgub, M., Ashour, A., Lam, D., Dai, X. (2017). Tests of self-compacting concrete filled elliptical steel tube columns. Thin-Walled Structures, 110, 27-34. https://doi.org/10.1016/j.tws.2016.10.015
17. [17] Gardner, L., Chan, T.M. (2007). Cross-section classification of elliptical hollow sections. Steel and Composite Structures, 7, 185-200. http://dx.doi.org/10.12989/scs.2007.7.3.185
18. [18] Chan, T.M., Gardner, L. (2008). Compressive resistance of hot-rolled elliptical hollow sections. Engineering Structures, 30, 522-532. https://doi.org/10.1016/j.engstruct.2007.04.019
19. [19] Gardner, L., Chan, T.M., Wadee, M.A. (2008). Shear response of elliptical hollow sections. Structures and Buildings, 161, 301-309. https://doi.org/10.1680/stbu.2008.161.6.301
20. [20] Chan, T.M., Gardner, L. (2008). Bending strength of hot-rolled elliptical hollow sections. Journal of Constructional Steel Research, 64, 971-986. https://doi.org/10.1016/j.jcsr.2007.11.001
21. [21] Chan, T.M., Gardner, L. (2009). Flexural buckling of elliptical hollow section columns. Journal of Structural Engineering, 135, 546-557. https://doi.org/10.1061/(ASCE)ST.1943-541X.0000005
22. [22] Ruiz-Teran, A.M., Gardner, L. (2008). Elastic buckling of elliptical tubes. Thin-Walled Structures, 46, 1304-1318. https://doi.org/10.1016/j.tws.2008.01.036
23. [23] Silvestre, N. (2008). Buckling behaviour of elliptical cylindrical shells and tubes under compression. International Journal of Solids and Structures, 45, 4427-4447. https://doi.org/10.1016/j.ijsolstr.2008.03.019
24. [24] Gardner, L., Chan, T.M., Abela, J.M. (2011). Structural behaviour of elliptical hollow sections under combined compression and uniaxial bending. Advances in Steel Construction, 7, 86-112. https://doi.org/10.18057/IJASC.2011.7.1.6
25. [25] Lam, D., Gardner, L., Burdett, M. (2010). Behaviour of axially loaded concrete-filled stainless steel elliptical stub columns. Advances in Structural Engineering, 13, 493-500. https://doi.org/10.1260/1369-4332.13.3.493
26. [26] Sheehan, T., Dai, X.H., Chan, T.M., Lam, D. (2012). Structural response of concrete-filled elliptical steel hollow sections under eccentric compression. Engineering Structures, 45, 314-323. https://doi.org/10.1016/j.engstruct.2012.06.040
27. [27] GB. GB50936: Technical code for concrete filled steel tubular structures (English Version). Ministry of Housing and Urban-Rural Development of the People’s Republic of China, Code of China 2014.
28. [28] GJB. GJB 4142-2000: Technical specifications for early-strength model composite structure used for navy port emergency repair in wartime [in Chinese]. 2001.
29. [29] ACI318. Building code requirements for reinforced concrete. American Concrete Institute, 2002.
30. [30] AISC. Load and resistance factor design specification, for structural steel buildings. American Institute of Steel Construction, 2010.
31. [31] AIJ. Standard for structural calculation of steel reinforced concrete structures (In Japanese). Architectural Institute of Japan, 2002.
32. [32] BSI. BS 5400-5: Steel, concrete and composite bridges - Part 5: Code for practice for the design of composite bridges. British Standards Institute, 2005.
33. [33] CSA. CAN/CSA-S16-01: Steel structures for buildings (limit states design). Canadian Standards Association, 2001.
34. [34] CSA. CAN/CSA-S16-09: Steel structures for buildings (limit states design). Canadian Standards Association, 2009.
35. [35] EC4. Eurocode 4: Design of composite steel and concrete structures – Part 1.1: general rules and rules for buildings. European Standards, 2004.
36. [36] Corus. Celsius 355 ® Ovals – size and resistances. Structural & Conveyance Business, 2004.
37. [37] EC3. Eurocode 3: Design of steel structure – Part 1.1: general rules and rules for buildings. European Standards, 1993.