Bending tests and finite element analysis of lipped channels with complex edge stiffeners and web stiffeners

Abstract

In order to study the bearing capacity and stability behavior of cold-formed steel flexural members with complicated sections, a total of 12 specimens divided into 6 groups were tested, including 3 groups of pure bending tests and non-pure bending tests each. There were three types of sections considered in this investigation, including channels with complex edge stiffeners (called B1-section), Σ section with complex edge stiffeners (called B2-section), and channels with complex edge stiffeners and V-type web stiffeners (called B3-section). Local buckling, distortional buckling and interaction buckling between them were observed in tests. The experimental results indicate that the bending strengths of B2-section specimens were the largest of these three types of specimens under the same conditions. It is found that the bending strength of B2-section specimens was increased by 6.47% for pure bending state and 8.12% for non-pure bending state, compared with that of B1-section specimens. Bending strength of B3-section specimens was almost the same with that of B1-section specimens under pure bending, but a little smaller than that of B1-section under non-pure bending state. It is also shown that B2-section specimens have better plastic deformation behavior than the other two sections. In addition, a non-linear finite element model was presented and verified against tests. The finite element analysis results agree well with experimental bending strength and failure modes.

Keywords

cold-formed steel / channels with complex edge stiffeners / web stiffeners / bending strength / buckling

References

[1] HancockG J. Design for distortional buckling of flexural members [J]. Thin-Walled Structures, 1997, 27(1): 3-12

[2] YuC, SchaferB W. Local buckling tests on cold-formed steel beams [J]. Journal of Structural Engineering, 2003, 129(12): 1596-1606

[3] YuC, SchaferB W. Distortional buckling tests on cold-formed steel members in bending [J]. Journal of Structural Engineering, 2006, 132(4): 515-528

[4] HancockG J. Cold-formed steel structures [J]. Journal of Constructional Steel Research, 2003, 59(4): 473-487

[5] RondalJ. Cold formed steel members and structures: General Report [J]. Journal of Constructional Steel Research, 2000, 55(1–3): 155-158

[6] SchaferB W. Cold-formed steel structures around the word—A review of recent advances in applications, analysis and design [J]. Steel Construction, 2011, 4(3): 1-9

[7] BamagaS O, TahirM M, TanT C, MohammadS, YahyaN, SalehA L, MustaffarM, OsmanM H, RahmanA B A. Feasibility of developing composite action between concrete and cold-formed steel beam [J]. Journal of Central South University, 2013, 20(12): 3689-3696

[8] MacdonaldM, HeiyantuduwaM A, RhodesJ. Recent developments in the design of cold-formed steel members and structures [J]. Thin-Walled Structures, 2008, 46(7–9): 1047-1053

[9] SchaferB W, SarawitA, PekozT. Complex edge stiffeners for thin-walled members [J]. Journal of Structural Engineering, 2006, 132(2): 212-226

[10] PhamC H, HancockG J. Experimental investigation and direct strength design of high-strength, complex c-sections in pure bending [J]. Journal of Structural Engineering, 2013, 139(11): 1842-1852

[11] PhamC H, HancockG J. Direct strength design of cold-formed purlins [J]. Journal of Structural Engineering, 2009, 135(3): 229-238

[12] SchaferB W, LiZ, MoenC D. Computational modeling of cold-formed steel [J]. Thin-Walled Structures, 2010, 48(1011): 752-762

[13] MoenC D, SchudlichA, HeydenA V D. Experiments on cold-formed steel c-section joists with unstiffened web holes [J]. Journal of Structural Engineering, 2013, 139(5): 695-704

[14] SchaferB W, PekozT. Laterally braced cold-formed steel flexural members with edge stiffened flanges [J]. Journal of Structural Engineering, 1999, 125(2): 118-127

[15] GB/T228–2002. Chinese standard for metallic materials-tensile testing at ambient temperature [S] 2002. (in Chinese)

[16] DubinaD, UngureanyV. Effect of imperfections on numerical simulation of instability behavior of cold-formed steel specimens [J]. Thin-Walled Structures, 2002, 40(3): 239-262

[17] WangC-g, ZhangZ-n, ZhaoD-q, LiuQ-qing. Compression tests and numerical analysis of web-stiffened channels with complex edge stiffeners [J]. Journal of Constructional Steel Research, 2016, 116(1): 29-39