بررسی تأثیر استفاده از ستون مرکب و مهاربند طناب الیاف مصنوعی بر مقاومت انفجاری قاب پرتال

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشیار گروه عمران، دانشگاه صنعتی نوشیروانی بابل

2 کارشناس ارشد سازه، دانشگاه آزاد علوم تحقیقات فارس

چکیده

چکیده
در این تحقیق به ارزیابی رفتار قاب با ستون‌ فولادی میان تهی در برابر بارگذاری انفجاری پرداخته شده است. به منظور افزایش مقاومت این قاب دو راهکار پیشنهاد می شود: نخست استفاده از مهاربند ضرب‌دری طناب الیاف مصنوعی و دوم پر کردن ستون‌ سمت انفجار قاب با بتن غیر مسلح، که به اصطلاح به آن ستون مرکب گفته می‌شود. نرم افزار اجزای محدود مورد استفاده، کد تجاری شده ABAQUS می‌باشد و برای تحلیل از روش دینامیکی صریح در حل عددی استفاده شد.
این پژوهش نشان می‌دهد که استفاده از مهاربند طناب الیاف مصنوعی، به‌ویژه در انفجارهای بزرگ که نیروی شلاقی شدیدی در طناب ظاهر می‌شود، تا حدی جابه‌جایی کلی قاب را بهبود می‌بخشد. با این وجود توانایی کاهش تغییرشکل‌های پلاستیک موضعی قاب را نداشته است. این مشکل با بهره‌گیری از ستون مرکب تا حد زیادی برطرف می‌شود. به‌طوری که پر کردن ستون سمت انفجار قاب با بتن، به‌طور چشمگیری جابه‌جایی‌های کلی و تغییر شکل‌های موضعی قاب را کاهش می دهد. نکته قابل توجه در بررسی‌های قاب با ستون مرکب این است که، بتن با مقاومت پایین‌تر در اثر اعمال نرخ کرنش، بسیار شبیه به بتن قوی‌تر رفتار می‌کند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Investigation on usage the composite column and synthetic fiber rope brace on blast resistance of portal frame

نویسندگان [English]

  • A. Mirza Goltabar Roshan 1
  • M. H. Shakibafar 2
1 Associate Professor, Department of Civil Engineering, Noshirvani University of Technology
2 M.Sc. Student, Department of Civil Engineering, Science and Research Branch, Islamic Azad University of Fars
چکیده [English]

In this research, behavior of portal frame with hollow section steel columns (box sections) is investigated
against explosive loading. In order to increase the resistance of the frame, two strategies are
suggested: First, using synthetic fiber ropes with initial slackness as x brace; second, filling the frame
column on blast side with concrete which is referred to as composite column. The finite element analysis
software used is the commercialized ABAQUS code and to analyze the finite element model, an explicit
dynamic method was used in the numerical solution. This study indicates that the use of synthetic fiber
rope brace, especially in large blasts that intense snap loads appears in the rope, improves the total
displacement of the frame. However, it has not been capable of reducing the plastic deformation of the
local points of the frame subjected to direct blast. This problem was rectified greatly using composite
columns. Filling the frame column with concrete on blast side can reduce the total displacements and
local deformations of the frame significantly. The remarkable thing in studying frames with composite
columns is that by applying strain rate, concrete with lower strength behaves like stronger concrete.

کلیدواژه‌ها [English]

  • Blast Loading
  • Portal Frame
  • X-Brace
  • Synthetic Fiber Rope
  • Composite Column
  • ABAQUS/ Explicit
  • Dynamics Non-Liner Analyses
[1] Fung, T. C. and Chow, S. K.; “Responses of Blast Loading by Complex Time Step Method,” Journal of Sound and Vibration, Vol. 223, No. 1, pp. 23-48, 1999.
[2] Dharaneepathy, M. V.; Keshava Rao, M. N. and Santhakumar, A. R.; “Critical Distance for Blast- Resistant Design,” Computers and Structures, Vol. 54, No. 4, pp. 587-595, 1995.
[3] Williams, M. S. and Newell, J. P.; “Methods for the Assessment of the Blast Response of Engineering Structures,” Earthquake, Blast and Impact: Measurement and Effects of Vibration, Society for Earthquake and Civil Engineering Design E and F NSpon, London, pp. 176-185, 1991.
[4] Cormie, D.; Mays, G. and Smith, P.; “Blast effects on Buildings: Design of Buildings to Optimize Resistance to Blast Loading,” London, Thomas Telford, Ltd., American Society of Civil Engineers, ISBN: 0-7277-2030-9, 1995.
[5] Shope, R. L. and Plaut, R. H.; “Critical Blast Load for Two-Span Compressed Steel Columns,” Proceedings of the 13th Engineering Mechanics Division Conference, N. P. Jones and R. G. Ghanem, eds, 1999.
[6] Miyamoto, H. K. and Taylor, D.; “Structural Control of Dynamic Blast Loading,” Advanced Technology in Structural Engineering, Proceedings from Structures Congress, ASCE, Reston, VA, 2000, CD-ROM.
[7] Pearson, N. J.; “Experimental Snap Loading of Synthetic Fiber Ropes,” M.Sc. Thesis, Virginia Polytechnic Institute and State University, Blacksburg, VA, 2002.
[8] Hennessey, C. M.; “Analysis and Modeling of Snap Loads on Synthetic Fiber Ropes,” M.Sc. Thesis, Virginia Polytechnic Institute and State University, Blacksburg, VA, 2003.
[9] Motley, M. R. and Plaut, R. H.; “Application of Synthetic Fiber Ropes to Reduce Blast Response of a Portal Frame,” Int. J. Structural Stability and Dynamics, Vol. 6, No. 4, pp. 513-526, 2006.
[10] Zanganeh, K. A.; “Shear Strength of the Reinforced Concrete Beams Subjected to Blast Loading,” M.Sc. Thesis, KTH Architecture and the Building Environment, Stockholm, Sweden, 2012.
[11] Hennessey, C. M., Pearson, N. J. and Plaut, R. H.; “Experimental Snap Loading of Synthetic Ropes,” Shock Vib., Vol. 12, pp. 163–175, 2005.
[12] Ryan, J. C.; “Analytical and Experimental Investigation of Improving Seismic Performance of Steel moment Frames Using Synthetic Fiber Ropes,” Ph.D. Dissertation, Virginia Polytechnic Institute and State University, Blacksburg, VA, 2006.
[13] Department of the Army, Structures to Resist the Effects of Accidental Explosions, 1990, Report TM5- 1300.
[14] Nayal, R. and Rasheed, H. A.; “Tension Stiffening Model for Concrete Beams Reinforced with Steel and FRP Bars,” Journal of Materials in Civil Engineering, Vol. 18, No. 6, pp. 831-841, 2006.
[15] Hsu, L. S. and Hsu, C. T.; “Complete Stress- Strain Behavior of High-Strength Concrete under Compression,” Magazine of Concrete Research, Vol.46, No. 169, pp. 301-312, 1994.
[16] Ngo, T.; Mendis, P.; Gupta, A. and Ramsay, J.; “Blast Loading and Blast Effects on Structures,” Int. J. Struc.Eng., Australia, pp. 76-91, 2007.
[17] Telford, T.; “MC90 CEB-FIP Model Code 1990, Design Code,” 6th Edition, Lausanne, Switzerland, 1993
[18] Malvar, L. J. and Crawford, J. E.; “Dynamic Increase Factors for Concrete,” Department of Defence Explosives Safety Seminar (DDESB), Orlando FL, USA, 1998.
[19] Hibbitt; Karlsson and Sorensen; “ABAQUS User’s Manual,” Pawtucket, 6th Edition, 2011.