Investigation of different methods in strengthening braced steel frame under blast load

Document Type : Research

Authors

1 PhD student in structural engineering, Kharazmi University, Tehran, Iran.

2 University of Tabriz, Tabriz, Iran.

Abstract

Unpredicted loading caused by blast or impact may lead to severe damage in structures. Such damage may affect the whole structural performance. Connections are the key contributor to the integrity and energy dissipation capacity of the structural steel systems and play the most important role in mitigating such consequences. In the view of the importance of connections, finite element analysis is used in this paper to study the behavior of braced steel frame under blast loading using ABAQUS finite element software. This Frame is adopted from a hospital building. Firstly, the behavior of the frame is investigated under near-field blast load to locate the regions that are susceptible to damage. Then according to the damage, five different possible reinforcing scenarios are proposed, and the advantages and drawbacks of each one are investigated. It is observed that asymmetrical deformations and damages are notable due to the front members’ severe local damage. The damage in the structure decreases rapidly as the height increases. In addition, the vertical web stiffeners and triangular plates on the top and bottom flanges eliminate the severe plastic strain and stress concentration in the connection zone causing the critical regions to move toward the middle of the beam that is desirable. It is also observed that continuous reinforcement of the beam webs with web sheets on both sides, significantly reduces the stresses on the web. This is a more effective way than the web stiffeners because of fewer stress changes in other members due to minor changes in the stiffness of the connected members.

Keywords


1. Khandelwal, K., S. El-Tawil, and F. Sadek, Progressive collapse analysis of seismically designed steel braced frames. Journal of Constructional Steel Research, 2009. 65(3): p. 699-708. [DOI:10.1016/j.jcsr.2008.02.007]
2. Astaneh-Asl, A., et al., Use of catenary cables to prevent progressive collapse of buildings. Report No.: UCB/CEE-STEEL-2001/02, 2001.
3. Marjanishvili, S., Progressive analysis procedure for progressive collapse. Journal of Performance of Constructed Facilities, 2004. 18(2): p. 79-85. [DOI:10.1061/(ASCE)0887-3828(2004)18:2(79)]
4. Liu, J., Preventing progressive collapse through strengthening beam-to-column connection, Part 1: Theoretical analysis. Journal of Constructional Steel Research, 2010. 66(2): p. 229-237. [DOI:10.1016/j.jcsr.2009.09.006]
5. Ellingwood, B.R., Mitigating risk from abnormal loads and progressive collapse. Journal of Performance of Constructed Facilities, 2006. 20(4): p. 315-323. [DOI:10.1061/(ASCE)0887-3828(2006)20:4(315)]
6. Ellingwood, B.R. and E. Leyendecker, Approaches for design against progressive collapse. Journal of the Structural Division, 1978. 104(3): p. 413-423. [DOI:10.1061/JSDEAG.0004876]
7. Smith, S.J., D.M. McCann, and M.E. Kamara, Blast resistant design guide for reinforced concrete structures. 2009.
8. Cranz, C., Lehrbuch der ballistik. Vol. 1. 1925: Рипол Классик. [DOI:10.1007/978-3-662-40321-1_1]
9. Hopkinson, B., British ordnance board minutes 13565. The National Archives, Kew, UK, 1915. 11.
10. Chun, S., Nonlinear fluid-structure interaction in a flexible shelter under blast loading. 2004, Virginia Tech. [DOI:10.2514/6.2005-2176]
11. Brode, H.L., Numerical solutions of spherical blast waves. Journal of Applied physics, 1955. 26(6): p. 766-775. [DOI:10.1063/1.1722085]
12. Henrych, J. and R. Major, The dynamics of explosion and its use. Vol. 569. 1979: Elsevier Amsterdam.
13. Kingery, C.N. and G. Bulmash, Airblast parameters from TNT spherical air burst and hemispherical surface burst. 1984: US Army Armament and Development Center, Ballistic Research Laboratory.
14. Smith, P. and J. Hetherington, Blast and ballistic loading of structures. Laxtons. 1994, Oxford.
15. Kazerani, S., N. Fanaie, and S. Soroushnia, Seismic behavior of drilled beam section in moment connections. Numerical Methods in Civil Engineering, 2017. 1(4): p. 1-6. [DOI:10.29252/nmce.1.4.1]
16. Fanaie, N., S. Kazerani, and S. Soroushnia, Numerical study of slotted web drilled flange moment frame connection. Numerical Methods in Civil Engineering, 2017. 1(3): p. 16-23. [DOI:10.29252/nmce.1.3.16]
17. Ghalamzan Esfahani, F. and N. Fanaie, Finite element analysis of a rigid beam to column connection reinforced with channels. Numerical Methods in Civil Engineering, 2017. 2(1): p. 37-48. [DOI:10.29252/nmce.2.1.37]
18. Engelhardt, M. and T.A. Sabol, Testing of welded steel moment connections in response to the Northridge earthquake. Northridge steel update, 1994. 1.
19. Tamboli, A.R., Handbook of structural steel connection design and details. 1999: McGraw-Hill New York.
20. Popov, E.P., Seismic moment connections for moment-resisting steel frames. 1983: Earthquake Engineering Research Center, University of California.
21. Engelhardt, M.D. and T.A. Sabol, Reinforcing of steel moment connections with cover plates: benefits and limitations. Engineering structures, 1998. 20(4-6): p. 510-520. [DOI:10.1016/S0141-0296(97)00038-2]
22. Engelhardt, M.D. and T.A. Sabol, Seismic‐resistant steel moment connections: developments since the 1994 Northridge earthquake. Progress in structural engineering and materials, 1997. 1(1): p. 68-77. [DOI:10.1002/pse.2260010112]
23. Engelhardt, M. and A. Husain, Cyclic-loading performance of welded flange-bolted web connections. Journal of Structural Engineering, 1993. 119(12): p. 3537-3550. [DOI:10.1061/(ASCE)0733-9445(1993)119:12(3537)]
24. Civjan, S.A., M.D. Engelhardt, and J.L. Gross, Retrofit of pre-Northridge moment-resisting connections. Journal of Structural Engineering, 2000. 126(4): p. 445-452. [DOI:10.1061/(ASCE)0733-9445(2000)126:4(445)]
25. Jones, S.L., G.T. Fry, and M.D. Engelhardt, Experimental evaluation of cyclically loaded reduced beam section moment connections. Journal of Structural Engineering, 2002. 128(4): p. 441-451. [DOI:10.1061/(ASCE)0733-9445(2002)128:4(441)]
26. King, K.W., J.H. Wawclawczyk, and C. Ozbey, Retrofit strategies to protect structures from blast loading. Canadian Journal of Civil Engineering, 2009. 36(8): p. 1345-1355. [DOI:10.1139/L08-058]
27. Caldwell, T., Bomb blast damage to a concrete-framed office building Ceylinco House - Columbo, Sri Lanka, in Proceedings of Structures Congress. 1999: New Orleans, LA.
28. Corley, W.G., Lessons learned on improving resistance of buildings to terrorist attacks. Journal of Performance of Constructed Facilities, 2004. 18(2): p. 68-78. [DOI:10.1061/(ASCE)0887-3828(2004)18:2(68)]
29. Sabuwala, T., D. Linzell, and T. Krauthammer, Finite element analysis of steel beam to column connections subjected to blast loads. International Journal of Impact Engineering, 2005. 31(7): p. 861-876. [DOI:10.1016/j.ijimpeng.2004.04.013]
30. Urgessa, G.S. and T. Arciszewski, Blast response comparison of multiple steel frame connections. Finite Elements in Analysis and Design, 2011. 47(7): p. 668-675. [DOI:10.1016/j.finel.2011.01.009]
31. Caldwell, T. BOMB BLAST DAMAGE TO A CONCRETE-FRAMED OFFICE BUILDING-CEYLINCO HOUSE-COLOMBO, SRI LANKA. in 1999 New Orleans Structures CongressStructural Engineering Institute of American Society of Civil Engineers, Structural Association of Alabama, National Council of Structural Engineers Associations, Florida Structural Engineers Association, Louisiana Section of ASCE, Baton Rouge Branch of AStructural Engineering Association of American Society of Civil Engineers, Structural Engineers Association of Alabama, National Council of Structural Engineers Associations, Florida Structural Engineers Association, Louisiana Section of ASCE, Baton Rouge. 1999.
32. Krauthammer, T., Blast-resistant structural concrete and steel connections. International Journal of Impact Engineering, 1999. 22(9-10): p. 887-910. [DOI:10.1016/S0734-743X(99)00009-3]
33. Krauthammer, T., Structural concrete and steel connections for blast resistant design. Int J Impact Eng, 1999. 22(9-10): p. 887-910. [DOI:10.1016/S0734-743X(99)00009-3]
34. Explosions, A., TM 5-1300. The Design of Structures to Resist the Effects of US Department of the Army, Navy, and Air Force, 1990.
35. Krauthammer, T., J. Lim, and G. Oh. Lessons from using precision impact test data for advanced computer code validations. In 10th International Symposium on Interaction of the Effects of Munitions with Structures. 2001.
36. Krauthammer, T., et al. Three-dimensional structural steel frame connections under blast loads. In Proc. 73 Shock and Vibration Symposium, Shock rd and Vibration Information Analysis Center, Newport, RI. 2002.