Finite Element Modeling of Bolted Cold-Formed Steel Storage Rack Upright Frames

Abstract:

Steel storage racks, commonly assembled from cold-formed steel profiles, are braced in the cross-aisle direction, where bracing members are typically bolted between two uprights forming an “upright frame”. Especially for high-bay racks and racks supporting the building enclosure, accurately determining the transverse shear stiffness of upright frames is essential in calculating the elastic buckling load, performing earthquake design and serviceability checks. International racking specifications recommend different approaches to evaluate the said transverse shear stiffness. The Rack Manufacturers Institute (RMI) Specification conservatively uses an analytical solution based on Timoshenko and Gere's theory while the European (EN15512) and Australian (AS4084) Specifications recommend testing to be conducted. Previous studies have shown that Finite Element Analyses (FEA), solely using beam elements, fail to reproduce experimental test results and may overestimate the transverse shear stiffness by a factor up to 25. This discrepancy is likely attributed to the local deformations occurring at the bolted joints. In this paper, a commercially used upright frame configuration has been modeled using shell elements in FEA and the response is verified against published experimental test results. A good correlation is found between the FEA and test results, concluding that shell elements are able to fully capture the behaviour of the upright frame. Future studies on the use of the FE model are also presented.

• Periodical: Applied Mechanics and Materials (Volume 846)
• Pages: 251-257
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.846.251
• Online since: July 2016
• Authors: Nima Talebian*, Benoit P. Gilbert, Nadia Baldassino, Hong Guan
• Keywords: Cold-Formed Steel, Shear Stiffness, Steel Storage Racks, Structural Performance, Upright Frames

References

[1] Gilbert BP, Rasmussen KJR, Baldassino N, Cudini T, Rovere L. Determining the transverse shear stiffness of steel storage rack upright frames. Journal of Constructional Steel Research, 2012. 78 107-116.

DOI: 10.1016/j.jcsr.2012.06.012

[2] Freitas AMS, Freitas MSR, Souza FT. Analysis of steel storage rack columns. Journal of Constructional Steel Research, 2005. 61(8), 1135-1146.

DOI: 10.1016/j.jcsr.2005.02.004

[3] Davies JM. Stability of unbraced pallet racks. Proceedings of the 5th International Speciality Conference on Cold-Formed Steel Structures, St. Louis, Missouri, U.S.A.; 1980. p.409–28.

[4] Sajja SR, Beale RG, Godley MHR. Shear stiffness of pallet rack upright frames. Journal of Constructional Steel Research, 2008. 64(7), 867-874.

DOI: 10.1016/j.jcsr.2008.01.025

[5] Baldassino N, Bernuzzi C. Analysis and behaviour of steel storage pallet racks. Thin-Walled Structures, 2000 37(4), 277-304.

DOI: 10.1016/s0263-8231(00)00021-5

[6] Prabha P, Marimuthu V, Saravanan M, Arul Jayachandran S. Evaluation of connection flexibility in cold formed steel racks. Journal of Constructional Steel Research, 2010. 66(7), 863-872.

DOI: 10.1016/j.jcsr.2010.01.019

[7] AS 4084. Steel storage racking. Sydney, Australia: Standards Australia; (2012).

[8] EN 15512. Steel static storage systems – adjustable pallet racking systems – principles for structural design. Brussels, Belgium: European Committee for Standardization (CEN); (2009).

DOI: 10.3403/30151881

[9] RMI. Specification for the design, testing and utilization of industrial steel storage racks. Charlotte, U.S.A.: Rack Manufacturers Institute; (2008).

[10] Timoshenko SP, Gere JM. Theory of elastic stability. 2nd edition. New York, U.S.A.: McGraw-Hill Book Company, Inc; (1961).

[11] Godley MHR, Beale, RG. Investigation of the effects of looseness of bracing components in the cross-aisle direction on the ultimate load-carrying capacity of pallet rack frames. Thin-Walled Structures, 2008. 46(7), 848-854.

DOI: 10.1016/j.tws.2008.01.011

[12] Rao SS, Beale RG, Godley MHR. Shear stiffness of pallet rack upright frames. Proceedings of the 7th International Speciality Conference on Cold-Formed Steel Structures, Orlando, Florida, U.S.A.; 2004, 295–311.

DOI: 10.1016/j.jcsr.2008.01.025

[13] Sajja SR. Cross-aisle shear stiffness of pallet rack upright frames. PhD thesis, Oxford Brooks Univesity, (2010).

[14] Abaqus. Abaqus ver. 6. 14 - user manual. Providence, U.S.A.: ABAQUS, Inc.; (2015).

[15] Kim TS, Kuwamura H, Finite element modeling of bolted connections in thin-walled stainless steel plates under static shear, Thin-Walled Structures, 2007. 45(4) 407-421.

DOI: 10.1016/j.tws.2007.03.006