DOI QR코드

DOI QR Code

A simplified method for evaluation of shear lag stress in box T-joints considering effect of column flange flexibility

  • Doung, Piseth (Department of Civil and Environmental Engineering, Tokyo Institute of Technology) ;
  • Sasakia, Eiichi (Department of Civil and Environmental Engineering, Tokyo Institute of Technology)
  • 투고 : 2019.03.27
  • 심사 : 2019.10.05
  • 발행 : 2020.01.25

초록

This study provides a simplified method for the evaluation of shear lag stress in rectangular box T-joints. The occurrence of shear lag phenomenon in the box T-joint generates stress concentration localized at both web-flange junctions of the beam, which leads to cracking or failure in the weld region of the joint. To prevent such critical circumstance, peak stress at the weld region is required to be checked during a preliminary design stage. In this paper, the shear lag stresses in the T-joints were evaluated using least-work solution in which the longitudinal displacements of the beam flange and web were presumed. The evaluation process considered particularly the effect of column flange flexibility, which was represented by an axial spring model, on the shear lag stress distribution. A simplified method for stress evaluation was provided to avoid solving complex mathematical problems using a stress modification factor βs from a parametric study. The results showed that the proposed method was valid for predicting the shear lag stress in the box T-joints manually, as well compared with finite element results. The results are further summarized, discussed, and clarified that more flexible column flange caused higher stress concentration.

키워드

참고문헌

  1. Abaqus/CAE (2017), User's Manual, Dassault Systemes; Velizy-Villacoublay, France.
  2. AIJ (2008), Recommendations for Design and Construction of Concrete Filled Steel Tubular Structures, Architectural Institute of Japan; Tokyo, Japan.
  3. ANSI/AISC 360-10 (2010), Specification for Structural Steel Buildings, American Institute of Steel Construction; Chicago, IL, USA.
  4. Chang, S.T. and Zheng, F.Z. (1987), "Negative shear lag in cantilever box girder with constant depth", J. Struct. Eng., 113(1), 20-35. https://doi.org/10.1061/(ASCE)0733-9445(1987)113:1(20).
  5. Chen, J., Shen, S.L., Yin, Z.Y. and Horpibulsuk, S. (2014), "Closed-form solution for shear lag with derived flange deformation function", J. Constr. Steel Res., 102(2014), 104-110. https://doi.org/10.1016/j.jcsr.2014.07.003.
  6. CIDECT 9 (2004), Design Guide for Structural Hollow Section Column Connections, Committee for International Development and Education on Construction of Tubular Structures, Koln, Germany.
  7. Dezi, L. and Mentrasti, L. (1985), "Nonuniform bending-stress distribution (shear lag)", J. Struct. Eng., 111(12), 2675-2690. https://doi.org/10.1061/(ASCE)0733-9445(1985)111:12(2675).
  8. Eurocode 3 (2005), Design of steel structures - Part 1-8: Design of joints, European Committee for Standardization; Brussels, Belgium.
  9. Fadden, M. and McCormick, J. (2013), "Evaluation of HSS-to-HSS Moment Connections for Seismic Applications", Structures Congress 2013, Pittsburgh, PA, USA, May. https://doi.org/10.1061/9780784412848.204.
  10. Hwang, W.S., Kim, Y.P., and Park, Y.M. (2004), "Evaluation of shear lag parameters for beam-to-column connections in steel piers", Struct. Eng. Mech., 17(5), 691-706. https://doi.org/10.12989/SEM.2004.17.5.691.
  11. JRA (2002), Specification for Highway Bridges, Part II: Steel Bridge Design, Japan Road Association; Japan.
  12. JSCE (2007), Standard Specifications for Steel and Composite Structures, Japan Society of Civil Engineers; Japan.
  13. Kristek, V., Evan, H.R., and Ahmad, M.K.M. (1990), "A shear lag analysis for composite box girders", J. Constr. Steel Res., 16(1), 1-21. https://doi.org/10.1016/0143-974X(90)90002-X.
  14. Kwan, A.K.H. (1996), "Shear lag in shear/core walls", J. Struct. Eng., 122(9), 1097-1104. https://doi.org/10.1061/(ASCE)0733-9445(1996)122:9(1097).
  15. Lee, K.-K., Loo, Y.-C. and Guan, H. (2001), "Simple analysis of framed-tube structures with multiple internal tubes", J. Struct. Eng., 127(4), 450-460. https://doi.org/10.1061/(ASCE)0733-9445(2001)127:4(450).
  16. Lin, Z. and Zhao, J. (2011), "Least-work solutions of flange normal stresses in thin-walled flexural members with high-order polynomial", Eng. Struct., 33(10), 2754-2761. http://dx.doi.org/10.1016/j.engstruct.2011.05.022.
  17. Miki, C. and Sasaki, E. (2005), "Fracture in steel bridge piers due to earthquake", Int. J. Steel Struct., 5(2), 133-140.
  18. Moazed, R., Szyszkowski, W.-A., and Fotouhi, R. (2009), "The in-plane behaviour and FE modeling of a T-joint connection of thin-walled square tubes", Thin-Walled Struct., 47(6-7), 816-825. https://doi.org/10.1016/j.tws.2009.01.006.
  19. Mohammadnejad, M. and Kazemi, H.H. (2018), "A new and simple analytical approach to determining the natural frequencies of framed tube structures", Struct. Eng. Mech., 65(1), 111-120. https://doi.org/10.12989/sem.2018.65.1.111.
  20. Okumura, T. and Ishizawa, N. (1968), "The design of knee joints for rigid steel frames with thin walled section", Trans. Japan Soc. Civ. Eng., 1968(153), 1-18. https://doi.org/10.2208/jscej1949.1968.153_1.
  21. Reissner, E. (1941), "Least-work solutions of shear lag problems", J. Aeronaut. Sci., 8(7), 284-291. https://doi.org/10.2514/8.10712.
  22. Reissner, E. (1946), "Analysis of shear lag in box beams by the principle of minimum potential energy", Q. Appl. Math., 4(3), 268-278. https://www.jstor.org/stable/43633559. https://doi.org/10.1090/qam/17176
  23. Sasaki, E., Takahashi, K., Ichikawa, A., Miki, C. and Natori, T. (2001), "Influences of stiffening methods on elasto-plastic behavior of beam-to-column connections of steel rigid frame piers", Proc. the Japan Soc. of Civ. Eng., 689(57), 201-214. https://doi.org/10.2208/jscej.2001.689_201.
  24. Serrano-Lopez, M.A., Lopez-Colina, C., Gonzalez, J. and Lopez-Gayarre, F. (2016), "A simplified FE simulation of welded I beam-to-RHS column joints", Int. J. Steel Struct., 16(4), 1095-1105. https://doi.org/10.1007/s13296-016-0028-5.
  25. Shi, Q.X. and Wang, B. (2016), "Simplified calculation of effective flange width for shear walls with flange", Struct. Design Tall Spec. Build., 25(12), 558-577. https://doi.org/10.1002/tal.1272.
  26. Tahan, N., Pavlovic, M.N., and Kotsovos, M.D. (1997), "Shear-lag revisited: the use of single fourier series for determining the effective breadth in plated structures", Comput. Struct., 63(4), 759-767. https://doi.org/10.1016/S0045-7949(96)00065-X.
  27. Tanabe, A. (2005), "Fatigue Retrofitting of Steel Bridge Frame Piers with High Seismic Performance", Ph.D. Dissertation; Tokyo Institute of Technology, Tokyo, Japan.
  28. Tenchev, R.T. (1996), "Shear lag in orthotropic beam flanges and plates with stiffeners", Int. J. Solids Struct., 33(9), 1317-1334. http://dx.doi.org/10.1016/0020-7683(95)00093-3.
  29. Timoshenko, S. and Woinowsky-Krieger, S. (1987), Theory of Plates and Shells, McGraw-Hill, Inc., Singapore.
  30. Winter, G. (1940), "Stress Distribution in and Equivalent Width of Flanges of Wide, Thin-Walled Steel Beams", NACA Technical Note No. 784; Cornell University, U.S.A.
  31. Zhou, W.-W., Jiang, L.Z., Liu, Z.J., and Liu, X.J. (2012), "Closed-form solution to thin-walled box girders considering effects of shear deformation and shear lag", J. Cent. South. Univ., 19(9), 2650-2655. https://doi.org/10.1007/s11771-012-1323-8.