اعتبار،چابکی،پاسخگویی

مطالعه عددی عملکرد تیرهای بتن مسلح دارای هسته توخالی تحت بار پیچشی به روش اجزاء محدود

نوع مقاله : مقاله پژوهشی

نویسندگان

1 استادیار رشته مهندسی عمران، دانشگاه مراغه، مراغه، ایران

2 دانشجوی کارشناسی ارشد مهندسی سازه، دانشگاه مراغه، مراغه، ایران

چکیده
پیچش در اجزای سازه‌ای بخصوص با مقاطع غیردایروی به دلیل ایجاد اعوجاج می‌تواند به عنوان یک بار بحرانی جهت ایجاد خرابی‌های اندک یا گسترده به حساب آید. امروزه صرفه‌جویی در مصالح مصرفی جزو اولویتهای اول مهندسی به حساب می‌آید و تیرها به عنوان یکی از اجزای اصلی و پرتکرار در سیستم باربری سازه‌ها می‌توانند نقش مهمی در پایداری سازه و در عین حال قیمت تمام شده سازه ایفا نمایند. در این راستا استفاده از تیرهای دارای هسته توخالی می‌تواند ما را به این مقصود نایل سازد. گاهاً می‌توان جهت حفظ پایداری یا مقاومتِ جز سازه‌ای با داشتن هسته توخالی از الیاف تقویت‌کننده استفاده کرد. الیاف FRP به عنوان مصالح جدید رشد‌یافته به‌طور برجسته‌ای با نسبت مقاومت به وزن بالا و دوام در محیط‌های خوردگی قابل توصیف هستند، که کاربرد آنها را به خصوص در سازه‌های فضایی و صنایع دریایی قابل توجه کرده است. در این پژوهش بعد از صحت‌سنجی نمونه آزمایشگاهی و اطمینان از نتایج بدست آمده، به مدل‌سازی 7 نمونه تیر بتنی با سوراخ دایره‌ای و مربعی با ورق CFRP تحت اثر نیروی پیچشی در حالات مختلف پرداخته شده است. نتایج بدست آمده نشان می‌دهند که نمونه‌هایی که در آنها از ورق‌های CFRP جهت بهبود عملکرد تیر بتنی استفاده گردیده، عملکرد یکسانی در ناحیه الاستیک داشته که با ادامه بارگذاری و تغییر شیب منحنی و وارد شدن نمونه‌ها به ناحیه پلاستیک شاهد افزایش اختلاف در بین نمونه‌ها بوده‌ایم. همچنین مقادیر تنش و کرنش پلاستیک در محل‌هایی که از ورق CFRP استفاده شده است از مقدار و شدت کمتری برخوردار بوده و همچنین در طول کمتری گسترش یافته است. به‌طوریکه در نمونه با ورق‌های CFRP در ابتدا و انتهای تیر مقدار تنش و کرنش توزیع شده در طول بیشتری ایجاد شده است. از نتایج قابل توجه این مطالعه اینکه ظرفیت تیر با هسته توخالی مربعی نسبت به دایروی با مساحت مقطع یکسان 15.71 درصد و نیز ظرفیت تیر با چهار دایره توخالی در مقطع نسبت به یک دایره در مساحتی برابر معادل 12.15 درصد افزایش ظرفیت پیچشی از خود نشان می‌دهد.

کلیدواژه‌ها

موضوعات

عنوان مقاله English

Numerical study of performance of reinforced concrete beams with hollow core under torsional loading by finite element method

نویسندگان English

Babak Alinejad 1
Saeed Mohammadi 2
1 Assisstant Professor, department of engineering, university of Maragheh, Maragheh, Iran.
2 MS student of structural eng., department of engineering, university of Maragheh, Maragheh, Iran.
چکیده English

Twisting in structural components, especially with non-circular sections due to distortion, can be considered as a critical load to cause small or extensive failures. Nowadays, the saving of consumable materials is considered among the first priorities of engineering, and beams, as one of the main and frequent components in the load-bearing system of structures, can play an important role in the stability of the structure and at the same time the cost price of the structure. In this regard, the use of beams with a hollow core can help us achieve this goal. FRP fibers can be described as new developed materials outstandingly with high strength-to-weight ratio and durability in corrosive environments, which has made their application especially significant in space structures and marine industries. In this research, after validating the laboratory sample and confirming the obtained results, the modeling of 7 samples of concrete beams with circular and square holes with CFRP sheets under the effect of torsional force in different situations was done. The obtained results show that the samples in which CFRP sheets were used to improve the performance of the concrete beam had the same performance in the elastic region, and with the continuation of loading and changing the slope of the curve and entering the plastic region of the samples, we have seen an increase in the difference between the samples. Also, the values of stress and plastic strain in the places where CFRP sheets were used were of lower value and intensity and also spread in a shorter length. So, in the sample with CFRP sheets at the beginning and end of the beam, the amount of stress and strain distributed in a larger length is created. One of the significant results of this study is that the capacity of a beam with a square hollow core shows a 15.71% increase in torsional capacity compared to a circle with the same cross-sectional area, as well as a 12.15% increase in the capacity of a beam with four hollow circles in the cross-section compared to a circle with an equal area.

کلیدواژه‌ها English

  • Reinforced concrete beam
  • torsion
  • CFRP sheet
  • elastic area
  • bearing capacity
  • plastic strain
  • Finite Element Method
Ahmmad A. Abbass, Sallal R. Abid, Farid H. Arna'ot, Raad A. Al-Ameri, Mustafa Özakça (2020).
Flexural response of hollow high strength concrete beams considering different size reductions,
Structures 23 69–86.
Aldemir, A., & Aydin, B. B. (2017, June). Effect of double-slotted beams on the frame behavior. In
XVII International Scientific Conference VSU. Sofia, Bulgaria.
Alsaeq, H. M. (2013). Effects of opening shape and location on the structural strength of RC deep beams
with openings. International Journal of Civil and Environmental Engineering, 7(6), 494-499.
Chalioris, C. E., & Karayannis, C. G. (2013). Experimental investigation of RC beams with rectangular
spiral reinforcement in torsion. Engineering structures, 56, 286-297.
Chyuan-Hwan Jeng, Min Chao, Hui-Chun Chuang, (2019),Torsion experiment and cracking-torque
formulae of hollow prestressed concrete beams, Engineering Structures 196 (2019) 109325.
Chin, S. C., Shafiq, N., & Nuruddin, M. F. (2011). Strengthening of RC beams containing large opening
at flexure with CFRP Laminates. Int. J. Civ. Environ. Eng, 5, 743-749.
Christopher K.Y, Leung, Gao Bo, Jang-Kyo Kim, (2006) Optimization of tapered end design for strip bonded to
RC beam Composites, Science and Technology, Pages 1266–1273.
Damian I. Kachlakev، "Finite Element Analysis and Model Validation of Shear Deficient Reinforced
Concrete Beams Strengthened With GCFRP Laminates"، United States Department of Transportation،
Federal Highway Administration.
Daryabigi, Seyyed Reza, Hosseini, Hossein, Rezaifar, Omid, (2006), Reinforcement and improvement
of concrete structures with CFRP materials, concepts and applications. Persian.
Dash, N. (2009). Strengthening of reinforced concrete beams using glass fiber reinforced polymer
composites (Doctoral dissertation).
Davodi, Mohammad Reza, Mostafaviyan, Amin, Fallahnejad, Hossein, (2012), Laboratory study of
damping changes in reinforced concrete beam reinforced with CFRP sheet, 9th International Congress
of Civil Engineering, Isfahan University of Technology, May 19-21. Persian.
El Maaddawy, T., & Sherif, S. (2009). FRP composites for shear strengthening of reinforced concrete
deep beams with openings. Composite Structures, 89(1), 60-69.
Elamary, A. S., Sharaky, I. A., & Alqurashi, M. (2021, August). Flexural behaviour of hollow concrete
beams under three points loading: Experimental and numerical study. In Structures (Vol. 32, pp. 1543-
1552). Elsevier.
Habibullah Akbar, (1389), design of reinforced concrete structures. Second edition. Azar publications
Ibrahim, A., Askar, H. S., & El-Zoughiby, M. E. (2022). Torsional behavior of solid and hollow concrete
beams reinforced with inclined spirals. Journal of King Saud University-Engineering Sciences, 34(5),
309-321.
Islam, M. R., Mansur, M. A., & Maalej, M. (2005). Shear strengthening of RC deep beams using
externally bonded FRP systems. Cement and Concrete Composites, 27(3), 413-420.
Jayajothi, P., Kumutha, R., & Vijai, K. (2013). Finite element analysis of FRP strengthened RC beams
using ANSYS.
Jeng, C. H., Chao, M., & Chuang, H. C. (2019). Torsion experiment and cracking-torque formulae of
hollow prestressed concrete beams. Engineering Structures, 196, 109325.
Karayannis, C. G., & Chalioris, C. E. (2013). Shear tests of reinforced concrete beams with continuous
rectangular spiral reinforcement. Construction and Building Materials, 46, 86-97.
Krishna, M. S., Kumar, G. S., & Thomas, A. C. (2021). Behaviour of reinforced concrete beams bonded
with side bonded FRP sheets. Materials Today: Proceedings, 43, 2404-2410.
69-90 ،)10(6 ، نشریه عمران و پروژه، 1403
https://doi.org/10.22034/cpj.2024.476424.1319
90
M, Mohammadhassani، MohdZaminJumaat، Ashraf Ashour and Mohameed Jameel، "Failure modes
and serviceability of high strength self-compacting concrete deep beams"، Department of Civil
Engineering، University of Malaya، Malaysia، Department of Civil Engineering، University of
Bradford، UK،2011.
Maheri, Mahmoud R, (1995), Recent Advances In Seismic Retrofit of Rc Frames, In Asian Journal of Civil
Engineering (Building And Housing) Vol. 6, No. 5, Pages 373-391.
Mansour, W., Ebead, U., Nagib, M. T., & Fayed, S. (2023, June). Behavior of hollow self-compacted
concrete beams reinforced with aluminum sections. In Structures (Vol. 52, pp. 549-567). Elsevier.
Maqsoodi, Ali Akbar, Saeed Ghasemi, Rahnama Flavarjani, Ismail, (2012), Deformability of posttensioned
beams reinforced with CFRP, 9th International Congress of Civil Engineering, Isfahan
University of Technology, May 19-21.Persian.
McSwiggan, C., & Fam, A. (2017). Bio-based resins for flexural strengthening of reinforced concrete
beams with FRP sheets. Construction and building materials, 131, 618-629.
Mostofi Nejad d. (1385). Reinforced concrete structures (first volume), Arkan publications. Persian.
Nedjhioui, O., Madi, R., Nedjhioui, M., & Guenfoud, M. (2023, November). Flexural behaviour of
hollow reinforced concrete T-beams strengthened or retrofitted with carbon-fibre-reinforced laminates:
Experimental and numerical investigation. In Structures (Vol. 57, p. 105222). Elsevier.
Obaidat, Y. T., Heyden, S., Dahlblom, O., Abu-Farsakh, G., & Abdel-Jawad, Y. (2011). Retrofitting of
reinforced concrete beams using composite laminates. Construction and Building Materials, 25(2), 591-
597.
Ohkubo, M., & Hamamoto, T. (2004, August). Developing reinforced concrete slotted beam structures
to reduce earthquake damage and to enhance seismic structural performance. In Proceedings of the 13th
annual world conference on earthquake engineering, Vancouver.
Panahi Darcheh, Mohammad, Arabzadeh, Abolfazl, (2008), Effective parameters on shear strengthening
of reinforced concrete deep beams using CFRP sheets, 8th International Congress of Civil Engineering,
Shiraz, Shiraz University. Persian.
Ramana, V. P. V., Kant, T. A. R. U. N., Morton, S. E., Dutta, P. K., Mukherjee, A. B. H. I. J. I. T., &
Desai, Y. M. (2000). Behavior of CFRPC strengthened reinforced concrete beams with varying degrees
of strengthening. Composites Part B: Engineering, 31(6-7), 461-470.
Sayed, A. M., Wang, X., & Wu, Z. (2013). Modeling of shear capacity of RC beams strengthened with
FRP sheets based on FE simulation. Journal of Composites for Construction, 17(5), 687-701.
Sharbatdar, Mohammad Kazem, (2012), Strengthening and improvement of civil infrastructures with
CFRP polymer fiber composites, Semnan University Publications. Persian.
Shatarat, N., Katkhuda, H., & Alqam, M. (2016). Experimental investigation of reinforced concrete
beams with spiral reinforcement in shear. Construction and Building Materials, 125, 585-594.
Shatarat, N., Mahmoud, H. M., & Katkhuda, H. (2018). Shear capacity investigation of self compacting
concrete beams with rectangular spiral reinforcement. Construction and Building Materials, 189, 640-
648.
Yang, J., Haghani, R., Blanksvärd, T., & Lundgren, K. (2021). Experimental study of FRP-strengthened
concrete beams with corroded reinforcement. Construction and Building Materials, 301, 124076.
Yang, K. H., Kim, G. H., & Yang, H. S. (2011). Shear behavior of continuous reinforced concrete Tbeams
using wire rope as internal shear reinforcement. Construction and Building Materials, 25(2), 911-
918.
Yin, J., & Wu, Z. S. (2003). Structural performances of short steel-fiber reinforced concrete beams with
externally bonded FRP sheets. Construction and building materials, 17(6-7), 463-470.
Zhou, J., Yu, P., Yoo, D. Y., Yu, L., & Ke, L. (2023). Effectiveness of flange plates on torsional
behaviors of ultra-high-performance fiber-reinforced concrete hollow beams. Developments in the Built
Environment, 16, 100227.
  • تاریخ دریافت 11 مرداد 1403
  • تاریخ بازنگری 17 شهریور 1403
  • تاریخ پذیرش 19 شهریور 1403
  • تاریخ اولین انتشار 19 شهریور 1403
  • تاریخ انتشار 01 دی 1403