Effect of FRP strengthening on the SHS brace collapse mechanism

Document Type : Article


Department of Civil Engineering, Amirkabir University of Technology, 424 Hafez Avenue, Tehran, Iran.


During an earthquake diagonal braces are designed to dissipate energy by yielding in tension and buckling in compression. However, local buckling occurring in the middle of the brace leads to immediate fracture. With the aim of strengthening braces against local buckling, wrapping FRP sheets in transverse direction is proposed in this study. Hitherto, the effect of FRP strengthening on the post-buckling behaviour of Square Hollow Section (SHS) tubes has not been investigated. A numerical model was generated and verified by previous research. Then, a comprehensive parametric study was conducted and the effect of slenderness ratio, number of FRP layers and FRP coverage percentage on post-buckling response of strengthening brace was explored within the study. Results indicate that utilising FRP is certainly successful at mitigating local buckling mode of long SHS braces Moreover, for short braces, applying enough numbers of FRP layers can change the mode of buckling from local to overall. Finally, an optimized length of FRP was suggested for strengthening of braces in accordance with their slenderness ratio.


Main Subjects

1. Gugerli, H. Inelastic cyclic behavior of steel bracing members", Ph.D. Dissertation, Michigan University (1982). 2. Fell, B.V., Large-Scale Testing and Simulation of Earthquake-Induced Ultra Low Cycle Fatigue in Bracing Members Subjected to Cyclic Inelastic Buckling, University of California Davis (2008). 3. Sheehan, T., Chan, T.-M., and Lam, D. Mid-length lateral deection of cyclically-loaded braces", Steel and Composite Structures, 18(6), pp. 1563-1576 (2015). 4. Shaback, B. and Brown, T. Behaviour of square hollow structural steel braces with end connections under reversed cyclic axial loading", Canadian Journal of Civil Engineering, 30(4), pp. 745-753 (2003). 5. Tremblay, R., Archambault, M.-H., and Filiatrault, A. Seismic response of concentrically braced steel frames made with rectangular hollow bracing members", Journal of Structural Engineering, 129(12), pp. 1626-1636 (2003). 6. American Institute of Steel Construction AISC 341- 05: Seismic provisions for structural steel buildings", American Institute of Steel Construction Inc, Chicago, IL (2005). 7. American Institute of Steel Construction AISC 341- 10: Seismic provisions for structural steel buildings", P. Shadan and M.Z. Kabir/Scientia Iranica, Transactions A: Civil Engineering 26 (2019) 3072{3084 3083 American Institute of Steel Construction Inc, Chicago, IL (2010). 8. Nassirnia, M., Heidarpour, A., Zhao, X.-L., and Minkkinen, J. Innovative hollow corrugated columns: A fundamental study", Engineering Structures, 94, pp. 43-53 (2015). 9. Javidan, F., Heidarpour, A., Zhao, X.-L., and Minkkinen, J. Performance of innovative fabricated long hollow columns under axial compression", Journal of Constructional Steel Research, 106, pp. 99-109(2015). 10. Teng, J.G., Chen, J.F., Smith, S.T., Lam, L. FRP Strengthened RC Structures, UK: John Wiley & Sons (2002). 11. Bank, L.C., Composites for Construction: Structural Design with FRP Materials, John Wiley & Sons (2006). 12. Bakis, C., Bank, L.C., Brown, V., Cosenza, E., Davalos, J., Lesko, J., Machida, A., Rizkalla, S., and Trianta_llou, T. Fiber-reinforced polymer composites for construction-state-of-the-art review", Journal of Composites for Construction , 6(2), pp. 73-87 (2002). 13. Teng, J., Yu, T., and Fernando, D. Strengthening of steel structures with _ber-reinforced polymer composites", Journal of Constructional Steel Research, 78, pp. 131-143 (2012). 14. Zhao, X.-L. and Zhang, L. State-of-the-art review on FRP strengthened steel structures", Engineering Structures, 29(8), pp. 1808-1823 (2007). 15. Mertz, D.R. and Gillespie Jr, J.W. Rehabilitation of steel bridge girders through the application of advanced composite materials", (No. NCHRP-IDEA Project 011)" (1996). 16. Miller, T.C., Chajes, M.J., Mertz, D.R., and Hastings, J.N. Strengthening of a steel bridge girder using CFRP plates", Journal of Bridge Engineering, 6(6), pp. 514-522 (2001). 17. Tavakkolizadeh, M. and Saadatmanesh, H. Fatigue strength of steel girders strengthened with carbon _ber reinforced polymer patch", Journal of Structural Engineering, 129(2), pp. 186-196 (2003). 18. Ekiz, E., El-Tawil, S., Parra-Montesinos, G., and Goel, S. Enhancing plastic hinge behavior in steel exural members using CFRP wraps", Proc., 13th World Conf. on Earthquake Engineering, Vancouver (2004). 19. El-Tawil, S., Ekiz, E., Goel, S., and Chao, S.-H. Retraining local and global buckling behavior of steel plastic hinges using CFRP", Journal of Constructional Steel Research, 67(3), pp. 261-269 (2011). 20. Teng, J. and Hu, Y. Behaviour of FRP-jacketed circular steel tubes and cylindrical shells under axial compression", Construction and Building Materials, 21(4), pp. 827-838 (2007). 21. Sayed-Ahmed, E. Strengthening of thin-walled steel Isection beams using CFRP strips", Proceedings of the 4th Advanced Composites for Bridges and Structures Conference (2004). 22. Eksi, S., Kapti, A.O., and Genel, K. Buckling behavior of _ber reinforced plastic-metal hybrid-composite beam", Materials & Design, 49, pp. 130-138 (2013). 23. Ragheb, W.F. Inelastic local buckling and rotation capacity of steel I-beams strengthened with bonded FRP sheets", Journal of Composites for Construction, 21(1), p. 04016058 (2017). 24. Shaat, A.A.S. Structural behaviour of steel columns and steel-concrete composite girders retro_tted using CFRP", Ph.D. Dissertation, Queen's University (2007). 25. Shaat, A. and Fam, A.Z. Slender steel columns strengthened using high-modulus CFRP plates for buckling control", Journal of Composites for Construction, 13(1), pp. 2-12 (2009). 26. Shaat, A. and Fam, A. Axial loading tests on short and long hollow structural steel columns retro_tted using carbon _bre reinforced polymers", Canadian Journal of Civil Engineering, 33(4), pp. 458-470 (2006). 27. Bambach, M., Jama, H., and Elchalakani, M. Axial capacity and design of thin-walled steel SHS strengthened with CFRP", Thin-Walled Structures, 47(10), pp. 1112-1121 (2009). 28. Haedir, J. and Zhao, X.-L. Design of short CFRPreinforced steel tubular columns", Journal of Constructional Steel Research, 67(3), pp. 497-509 (2011). 29. Park, J.-W. and Yoo, J.-H. Axial loading tests and load capacity prediction of slender SHS stub columns strengthened with carbon _ber reinforced polymers", Steel and Composite Structures, 15(2), pp. 131-150 (2013). 30. Feng, P., Hu, L., Qian, P., and Ye, L. Buckling behavior of CFRP-aluminum alloy hybrid tubes in axial compression", Engineering Structures, 132(Supplement C) pp. 624-636 (2017). 31. Kabir, M.Z. and Nazari, A.R. Numerical study on reinforcing of thin walled cracked metal cylindrical columns using FRP patch", Scientia Iranica transaction A-Civil Engineering, 17(5), pp. 407-414 (2010). 32. Teng, J. and Hu, Y. Suppression of local buckling in steel tubes by FRP jacketing", Proceedings, 2nd International Conference on FRP Composites in Civil Engineering, Adelaide, Australia, pp. 8-10 (2004). 33. Batikha, M., Chen, J., Rotter, J., and Teng, J. Strengthening metallic cylindrical shells against elephant's foot buckling with FRP", Thin-Walled Structures, 47(10), pp. 1078-1091 (2009). 34. Haedir, J., Bambach, M., Zhao, X.-L., and Grzebieta, R. Strength of circular hollow sections (CHS) tubular beams externally reinforced by carbon FRP sheets in pure bending", Thin-Walled Structures, 47(10), pp. 1136-1147 (2009). 3084 P. Shadan and M.Z. Kabir/Scientia Iranica, Transactions A: Civil Engineering 26 (2019) 3072{3084 35. Zhao, X.-L., Fernando, D., and Al-Mahaidi, R. CFRP strengthened RHS subjected to transverse end bearing force", Engineering Structures, 28(11), pp. 1555-1565 (2006). 36. Alam, M.I., Fawzia, S., Zhao, X.-L., and Remennikov, A.M. Experimental study on FRP-strengthened steel tubular members under lateral impact", Journal of Composites for Construction, 21(5), p. 04017022 (2017). 37. Qingli, W. and Yongbo, S. Compressive performances of concrete _lled square CFRP-steel tubes (S-CFRPCFST)", Steel & Composite Structures: An International Journal, 16(5), pp. 455-480 (2014). 38. Yu, T., Hu, Y.M., and Teng, J.G. Cyclic lateral response of FRP-con_ned circular concrete-_lled steel tubular columns", Journal of Constructional Steel Research, 124(Supplement C), pp. 12-22 (2016). 39. Harries, K.A., Peck, A.J., and Abraham, E.J. Enhancing stability of structural steel sections using FRP", Thin-Walled Structures, 47(10), pp. 1092-1101 (2009). 40. Kim, Y.J. and Harries, K.A. Behavior of tee-section bracing members retro_tted with CFRP strips subjected to axial compression", Composites Part B: Engineering, 42(4), pp. 789-800 (2011). 41. Gao, X., Balendra, T., and Koh, C. Buckling strength of slender circular tubular steel braces strengthened by CFRP", Engineering Structures, 46, pp. 547-556 (2013). 42. El-Tawil, S. and Ekiz, E. Inhibiting steel brace buckling using carbon _ber-reinforced polymers: Largescale tests", Journal of Structural Engineering , 135(5), pp. 530-538 (2009). 43. Bruneau, M., Uang, C.-M., and Sabelli, S.R., Ductile Design of Steel Structures, McGraw Hill Professional (2011). 44. Davison, T. and Birkemoe, P. Column behaviour of cold-formed hollow structural steel shapes", Canadian Journal of Civil Engineering, 10(1), pp. 125-141 (1983). 45. Chan, S.L., Kitipornchai, S., and Al-Bermani, F.G. Elasto-plastic analysis of box-beam-columns including local buckling e_ects", Journal of Structural Engineering, 117(7), pp. 1946-1962 (1991). 46. ABAQUS/Standard, User's Manual- Version 6.11 (2011). 47. Hashin, Z. Failure criteria for unidirectional _ber composites", Journal of Applied Mechanics, 47(2), pp. 329-334 (1980). 48. Al-Zubaidy, H., Al-Mahaidi, R., and Zhao, X.-L. Finite element modelling of CFRP/steel double strap joints subjected to dynamic tensile loadings", Composite Structures, 99, pp. 48-61 (2013). 49. Fernando, N.D., Bond Behaviour and Debonding Failures in CFRP-Strengthened Steel Members, The Hong Kong Polytechnic University (2010).