Manuscript Information Authors

[1]	Yuwen Li, Gannett Fleming Inc., Valley Forge, Pennsylvania, United States.

Abstract

Design strengths of Structural Tees (WT-shapes, Tees) in axial compression are provided in Table 4-5 of the 14^th edition of AISC Manual of Steel Construction (the Manual) [1], with an assumption that the compression force is applied at the center of gravity (c.g.) of the cross section. However, in engineering practice, Tees are rarely loaded at the section’s c.g.; rather, they are eccentrically loaded at the ends through the gusset plates that welded or bolted to their flanges. Therefore, these Tees are subject to the axial compressive force and the bending moment induced by the eccentric end connections. Although the design strengths of eccentrically loaded WT-shapes are not provided in the Manual, they can be calculated based on AISC Specifications for Structural Steel Constructions (the Specifications) [2], albeit the design process is tedious and time consuming. However, if the Specifications are indiscriminately followed (called Approach 1 in this paper), the calculated strengths are too conservative. This paper discusses an alternate approach (Approach 2) allowed for by Commentary H2 of the Specifications, and the calculated strengths based on Approach 2 are larger and more reasonable than those based on Approach 1. Extensive Finite Element Nonlinear Analyses have been employed to validate the proposed approach. Finally, design tables for eccentrically loaded WT-shapes are provided to help engineers quickly determine the proper size of a WT-shape for their project.

Keywords

WT Shapes, Eccentrically Loaded, Eccentric Loading, Compression, Design Tables

Reference

[01]	AISC (2010), Manual of Steel Construction, 14th Edition, American Institute of Steel Construction, Inc., Chicago, Illinois.
[02]	AISC (2010a), Specification for Structural Steel Buildings, June 2010, American Institute of Steel Construction, Inc., Chicago, Illinois.
[03]	AISC (2011), Design Examples, Version 14, 2011, American Institute of Steel Construction, Inc., Chicago, Illinois.
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[06]	LUSAS Bridge Software, Version 15.2 (2016), FEA Ltd, Kingston-Upon-Thames, UK.
[07]	Galambos, T. V. (2001), “Strength of Singly Symmetric I-Shaped Beam-Columns,” AISC Engineering Journal, 2nd Quarter, 2001, pp. 65-77.
[08]	Ellifritt, D. S., et al. (1992), “Flexural Strength of WT Sections,” AISC Engineering Journal, 2nd Quarter, 1992, pp. 67-74.
[09]	Tito, J. A. (2013), “Eccentric Compression Test of WT Shape Steel Braces,” 11th LACCEI Latin American and Caribbean Conference for Engineering and Technology, 2013, Cancun, Mexico.
[10]	Li, Y. W. (2012), “Axial Capacities of Eccentrically Loaded Equal-Leg Single Angles: Comparisons of Various Design Methods,” AISC Engineering Journal, 4th Quarter, 2012, pp. 131-167.