CAPACITY OF MONO-SYMMETRIC GIRDERS WITH SLENDER WEBS IN PLATE GIRDER COMPOSITE BRIDGES

El-Mahdy, Ghada M.

CAPACITY OF MONO-SYMMETRIC GIRDERS WITH SLENDER WEBS IN PLATE GIRDER COMPOSITE BRIDGES

Document Type : Scientific and technological

Author

Ghada M. El-Mahdy

Associate Research Professor, Structures and Metallic Construction Research Institute, Housing and Building National Research Center (HBRC), Egypt

Abstract

Mono-symmetric plate girders are often used in simply supported composite bridges to eliminate local plate buckling in the compression flange during construction. This causes the neutral axis of the plate girder to shift downwards subjecting more of the web to compressive stresses due to bending. In slender webs this increases the possibility of local buckling in the compression part of the web during construction. However, depending on the slenderness (width-to-thickness ratio) of the web, the post-buckling reserve capacity may accommodate this local buckling within the elastic limit of the web for during construction loads. Hence, this would allow for the use of more slender webs in composite plate girder construction without the need for longitudinal web stiffeners or the reduction of the overall composite section due to local plate buckling in the web. Recommended values of stress level are given for mono-symmetric plate girders in the non-composite stage based on the results of a non-linear finite element analysis

Keywords

References

[1] Gupta, V.K., “Development of section classification criterion and ultimate flexural equation for composite I-girders”, Doctoral Dissertation, Saitama University, Japan, 2006.

[2] Gupta, V.K., Yoshiaki, O., and Nagai, M., “Development of web slenderness limits for composite I-girders accounting for initial bending moment”, Doboku Gakkai Ronbunshuu A (JSCE Journal of Structural and Earthquake Engineering), Vol. 62, No. 4, pp. 854-864, 2006.

[3] Basker, K., Shanmugan, N.E., and Thevendran, V., “Finite-element analysis of steel-concrete composite plate girder”, J. Struct. Eng., ASCE, Vol. 128, No. 9, pp. 1158-1168, 2002.

[4] Yakel, A.J. and Azizinamini, A., “Improved moment strength prediction of composite steel plate girders in positive bending”, J. Bridge Eng., ASCE, Vol. 10, No. 1, pp. 28-38, 2005.

[5] von Kármán, T., Sechler, E.E., and Donell, L.H., “Strength of thin plates in compression”, Transactions of the American Society of Mechanical Engineers, Vol. 54, No. APM-54-5, p. 53, 1932.

[6] Eurocode 3, Design of steel structures – Part 1.1 General structural rules (EN 1993-1-1:2003), European Committee for Standardization (CEN), Brussels, Belgium, 2005.

[7] ECOP-ASD, Egyptian Code of Practice for Steel Construction and Bridges – Allowable Stress Design, Egypt, 2001.

[8] American Iron and Steel Institute, Specification for the design of cold-formed steel structural members, AISI, Washington DC, 2007.

[9] Abu-Hamd, M.H. and Elmahdy, G.M., “The effective width of slender plate elements in plate girders”, Journal of Engineering and Applied Science, Faculty of Engineering - Cairo University, 50(2): 259-278, 2003.

[10] Elmahdy, G. and Abu-Hamd, M., “New formula for the effective width of slender plate elements”, Proceedings of the CSCE Annual Conference - 6th Structural Speciality Conference, Quebec City, Quebec, Canada, 2008.

[11] El-Mahdy, G. and Abu-Hamd, M., “Local buckling of slender plate girders in composite bridges”, Proceedings of the SSRC Annual Stability Conference, Orlando, Florida, USA, 2010.

[12] Eurocode 3, Design of steel structures – Part 1.5 Plated structural elements (EN 1993-1-5:2006), European Committee for Standardization (CEN), Brussels, Belgium, 2006.