The Collapse Analysis of the Lateral-Torsional Buckling of I-Shaped Stepped Steel Beams

https://doi.org/10.22146/jcef.56934

Kelsen Trista Kweenisky(1*), Naomi Pratiwi(2), Paulus Karta Wijaya(3)

(1) Department of Civil Engineering, Universitas Katolik Parahyangan, Bandung, INDONESIA
(2) Department of Civil Engineering, Universitas Katolik Parahyangan, Bandung, INDONESIA
(3) Department of Civil Engineering, Universitas Katolik Parahyangan, Bandung, INDONESIA
(*) Corresponding Author

Abstract


The use of a non-prismatic member such as a stepped beam as a design method has the ability to function as a tool for steel beams optimization. A cover plate is partially welded on the upper and lower flange of the member at the maximum bending moment location to increase its flexural strength and, under critical load, flexural members bend about its strong axis, displace to the lateral direction, and twist coincidentally through a phenomenon known as the Lateral-Torsional Buckling (LTB). There is, however, no equations in the AISC 360-16 specification to calculate the critical moment of a stepped beam (Mst). Therefore, this research focuses on developing Mst for a simply supported stepped beam which deforms on its shear center under static-transverse loading through the use of a collapse analysis and the behavior of the beam. The results showed the welded cover plates consequently increased the LTB resistance of the prismatic I-shaped steel beam from 9.8% to 202% while the critical moment increased more significantly with an increment in the ratio of the cover plate length to the unbraced length (α). The cover plate thickness was observed to have dominantly affected only a large α ratio while the post-buckling characteristic of large α showed a sudden collapse phenomenon. Furthermore, the LTB modification factor was generated in this study due to the initial geometrical imperfection from the first mode of Eigen shape with maximum amplitude Lb/2000 (Cb1) and stepped beam shape (Cst) which were required to estimate the critical moment of a stepped beam based on the AISC equation for a prismatic beam.

Keywords


Stepped Beam, Lateral Torsional-Buckling, Collapse Analysis, Critical Moment, Modification Factor

Full Text:

PDF


References

American Institute of Steel Construction, 2016. Specifications for Structural Steel Buildings, ANSI-AISC 360-16, AISC (American Institute of Steel Construction).

Alolod, S. & Park, J. S. 2018. Inelastic Buckling Strength of Stepped I-Beams at Midspan Subjected to Uniform Bending. Journal of the Korean Society of Hazard Mitigation, 18, 185-192.

Boissonnade, N. & Somja, H. Influence of imperfections in FEM modeling of lateral torsional buckling. Proceeding of the Annual Stability Conference Structural Stability Research Council, 2012. 18-21.

Dharma, A. P. & Suryoatmono, B. Non-Linear Buckling Analysis of Axially Loaded Column with Non-Prismatic I-Section. Journal of the Civil Engineering Forum, 2019. 263-274.

Galambos, T. V. & Surovek, A. E. 2008. Structural stability of steel : concepts and applications for structural engineers, Hoboken, N.J., John Wiley & Sons.

Kaehler, R., White, D. & Kim, Y. 2011. Steel design guide 25; frame design using web-tapered members. AISC, Chicago.

Mccormac, J. C. & Csernak, S. F. 2012. Structural steel design, Harlow, Pearson Education.

Park, J.-S. & Kang, Y.-J. 2004. Lateral Buckling of Stepped Beams under Linear Moment Gradient. Journal of Steel Structures, KSSC, 4, 71-81.

Salmon, C. G., Johnson, J. E. & MALHAS, F. A. 2008. Steel structures : design and behavior, Indianapolis, Ind., Prentice Hall.

Surla, A. & Park, J. 2015. Investigation of Effect of Steps in Inelastic-Buckling Strength of IBeams Subjected to Two Concentrated Loads Using Experimental Tests, Finite Element Analysis and Proposed Equations. Journal of Korean Society of Hazard Mitigation, 15, 1-12.

Surla, A. S. & Park, J. S. 2014. Investigation of lateral-torsional buckling strength trends in monosymmetric stepped I-beams subjected to several loading conditions. Journal of the Korean Society of Hazard Mitigation, 14, 33-42.

Trahair, N. S. & Kitipornchai, S. 1971. Elastic lateral buckling of stepped I-beams. Journal of the Structural Division, 97, 2535-2548.

Van Der AA, R. 2015. Numerical assessment of the design imperfections for steel beam lateral torsional buckling. Master thesis A-2015.102.

Yossef, N. 2015. Strengthening Steel I-Beams by Welding Steel Plates before or While Loading. International Journal of Engineering Research & Technology (IJERT), 4, 545-550.



DOI: https://doi.org/10.22146/jcef.56934

Article Metrics

Abstract views : 2307 | views : 1947

Refbacks

  • There are currently no refbacks.




Copyright (c) 2022 The Author(s)


The content of this website is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
ISSN 5249-5925 (online) | ISSN 2581-1037 (print)
Jl. Grafika No.2 Kampus UGM, Yogyakarta 55281
Email : jcef.ft@ugm.ac.id
Web Analytics JCEF Stats