بررسی آزمایشگاهی و تحلیلی شکل‌پذیری حلقه فولادی مرکب جهت نصب در مهاربندهای هم محور

نوع مقاله : مقاله کامل پژوهشی

نویسندگان

دانشکده مهندسی عمران، دانشگاه سمنان

چکیده

در دهه‌های گذشته، تحقیقات مختلفی جهت افزایش شکل‌پذیری مهاربندهای هم محور صورت گرفته است. یکی از روش‌های افزایش شکل‌پذیری و کنترل کمانش عضو فشاری مهاربندها، استفاده از المان شکل‌پذیر حلقه فولادی است. حلقه تعبیه شده تحت اثر نیروی محوری مهاربندها، تحت خمش قرار می‌گیرد و در نتیجه با استفاده از جمع شدن و بازگشت به حالت اولیه و ورود به مرحله غیر خطی و تشکیل مفاصل خمیری، در استهلاک انرژی زلزله تأثیر بسزایی خواهد داشت. از آنجایی که تنوع حلقه‌های فولادی محدود و تهیه آنها متناسب با ظرفیت مورد نیاز مقدور نیست، لذا اتخاذ روشی جهت افزایش ظرفیت باربری حلقه‌های موجود از جمله کمبودهای پژوهشی در این زمینه می‌باشد. هدف از این مقاله، افزایش ظرفیت باربری المان حلقه با استفاده از دو حلقه متداخل فولادی است که فضای بین آنها توسط ماده پلاستیک صنعتی (یا تفلون) پر شده است. در این پژوهش، علاوه بر مطالعات آزمایشگاهی، مدل‌سازی عددی با استفاده از تحلیل غیر خطی و به روش المان محدود و تحت اثر بار چرخه‌ای، مطالعه شده است. نتایج حاصله نشان داده است که تحلیل نظری المان مورد مطالعه از دقت لازم برخوردار بوده و با نتایج آزمایشگاهی انطباق خوبی دارد. همچنین المان دارای منحنی‌ هیسترزیس پهن بوده و شکل‌پذیری و جذب انرژی مناسبی دارد که ضریب شکل‌پذیری کششی آن 77/2 می‌باشد. بر این اساس، بیشترین نیروی کششی قابل تحمل المان و جابه‌جایی قائم نظیر آن به ترتیب 48/99 کیلونیوتن و 01/16 میلی‌متر می‌باشد. این مقادیر در اثر اعمال نیروی فشاری به ترتیب 55/101 کیلونیوتن و 50/11 میلی‌متر نتیجه شده است.

کلیدواژه‌ها

عنوان مقاله [English]

Experimental and analytical study on ductility of steel ring filled with compressive plastic, situated in concentric bracing system

نویسندگان [English]

  • Mohammad Ali Kafi
  • Ali Kheyroddin
  • Mohammad Hajforoush
Faculty of Civil Engineering, Semnan University, Semnan, Iran
چکیده [English]

One of the weakness of concentric braces is lower ductility and early buckling under compressive loading. One method to improve the ductility is to use energy-dissipater members situated at the intersection of the braces. Regarding this, the usage of steel rings made of steel pipes as an energy dissipater has been considered for solving weakness of ductility. Following this, the main objective of this study is to assess evaluate experimentally the dynamic behavior of steel ring filled with compressive plastic (S.R.P.) situated at the intersection of the braces. In addition, this connection was modeled by means of finite element (FE) method employing ABAQUS software. The accuracy of the FE models is confirmed using outputs of experimental studies where the nonlinear behavior of this connection was investigated both experimentally and numerically. Results indicate that the S.R.P. constructed from steel plates and plastic has a suitable performance relative to the pipe ring and exhibits good ductility and energy dissipation. In addition, this connection can enhance ductility of concentric braces in seismic loads. Concerning this matter, the brace with the S.R.P. ring shows a steady and wide hysteresis curve where tensile ductility factor of 2.77 was achieved. Another matter is that the maximum stress of this connection was obtained numerically in failure zone as indicated in experimental results. Furthermore, the maximum tensile load and corresponding vertical displacement were 99.48 kN, 16.01 mm, respectively, and also the maximum compressive load and corresponding vertical displacement were 101.55 kN and 11.5 mm, respectively.

کلیدواژه‌ها [English]

  • Experimental
  • Finite element
  • Steel Ring
  • Ductility
  • Braced Frame

مراجع

Abbasnia R, Vetr MG, Ahmadi R, Kafi MA, ‘‘Experimental and Analytical Investigation on the Steel Ring Ductility’’, Sharif Journal of Science and Technology, 2008, 52, 41-48.
Abbasnia R, Vetr MG, Kafi MA, ‘‘A study on functionality of dutiable element in ductility concentrically braces’’, 7th International Congress on Civil Engineering, Tarbiat Modares University, Tehran, Iran, 2006.
Andalib Z, Kafi MA, Kheyroddin A, Bazzaz M, ‘‘Experimental investigation of the ductility and performance of steel rings constructed from plates’’, Journal of Constructional Steel Research, 2014, 103, 77-88.
ATC40. Guidelines for Seismic Testing of Components of Steel Structures, Washington (DC), 1992.
Balendra T, Lim EL, Liaw CY, ‘‘Large-Scale Seismic Testing of Knee-Brace-Frame”, Journal of Structural Engineering, 1997, 123 (1), 11-19.
Bazzaz M, Kheyroddin A, Kafi MA, Andalib Z, ‘‘Evaluation of the seismic performance of off-center bracing system with ductile element in steel frames’’, Steel and Composite Structures, 2012, 12 (5), 445-464.
Bazzaz M, Andalib Z, Kafi MA, Kheyroddin A, ‘‘Evaluating the performance of OBS-C-O in steel frames under monotonic load’’, Earthquakes and Structures, 2015, 8 (3), 697-710.
Butterworth J, ‘‘Ductile concentrically braced frames using slotted bolted joints’’, SESOC Journal, 2000, 13 (1), 39-48.
Chen CC, Lu LW, ‘‘Development and experimental investigation proceedings of a ductile CBF system’’, the 4th National Conference of Earthquake Engineering, 1990, 2, 575-584.
Clark W, Tasia K, Aiken ID, Kimura I, ‘‘Evaluation of design methodologies for structures incorporating steel unbounded braces for energy dissipation’’, Proceedings of the 12th World Conference on Earthquake Engineering, Upper Hutt, New Zealand, 2000, 22-40.
Esmaeeli H, Kheyroddin A, kafei MA, Nikbakht H, “Comparison of Nonlinear Behavior of Steel Moment Frames Accompanies with RC Shear Walls or Steel Bracings” Journal of the Structural Design of Tall and Special Buildings, 2013, 22 (14), 1062-1074.
Grigorian CE, Yang TS, Popov EP, M EERE, ‘‘Slotted bolted connection energy dissipaters’’, Journal of Earthquake Spectra, 1993, 9 (3), 491-504.
Hibbitt D, Karlsson B, Sorensen P, ‘‘Abaqus Standard User′s Manual’’, Version (6.11-3), 2011.
Maheri MR, Akbari R, ‘‘Seismic behavior factor, R, for steel X-braced and knee-braced RC buildings’’, Journal of Engineering Structures,2003, 25 (12), 1505-1513.
Malek S, Pabsang P, Lohghalam A, ‘‘Introducing a new inactive dissipate system and comparing it with TADAS dissipate’’, First International Congress on Seismic Retrofitting, Amirkabir University of Technology, Tehran, Iran, 2006.
Marshall JD, Charney FA, ‘‘A hybrid passive control device for steel structures’’, I: Development and analysis, Journal of Constructional Steel Research, 2010, 66 (10), 1278-1286.
Marshall JD, Charney FA, ‘‘A hybrid passive control device for steel structures’’, II: Physical testing, Journal of Constructional Steel Research, 2010, 66 (10), 1287-1294.
Mualla IH, Belev B, ‘‘Performance of steel frame with a new friction damper device under earthquake excitation’’, Journal of Engineering Structures 2002, 24 (3), 365-371.
Murthy ANCK, “Application of Visco-Hyperelastic Devices in Structural Response Control structures’’, The Degree of Master of Sciense, Civil Engineering Department, Blacks-burg Polytechnic Institiute, Virginia Polytechnic Institute and State University, 2005.
Pall AS, Marsh C, ‘‘Response of friction damped braced frames’’, Journal of Structural Division, 1982, 108, No. ST6.
Rezaieian A, ‘‘Improving earthquake behavior of concentrically braced frames by being ductility them’’, Civil Engineering M.Sc. Thesis, Civil Engineering Department, Science & Technology University of Iran, Iran, 2002.
Roufegarinejad A, Sabouri S, ‘‘Nonlinear behavior of yielding damped bracing frames’’, 15th ASCE Engineering Mechanics Conference, Columbia University, New York, 2002.
Tehranizadeh M, ‘‘Passive energy dissipation device for typical steel frame building in Iran’’, Journal of Engineering Structures, 2000, 23 (6), 643-655.
Thomopoulos K, Koltsakis E, ‘‘Connections of CHS concrete-filled diagonals of X-bracings’’, Journal of Constructional Steel Research, 2003, 59 (6), 665-678.
Tsai KC, EERI M, Chen HW, Hong CP, Su YF, ‘‘Design of steel Triangular Plate Energy Absorbers for Seismic Resistant Construction”, Journal of Earthquake Spectra, 1993, 9 (3), 505-528.
Vetr MG, ‘‘Seismic behavior analysis and design of vertical sheering’’, Ph.D. Dissertation, T.U. Darmeatadt Germang, 1997.
Vetr MG, Abbasnia R, Kafi MA, ‘‘Energy absorption increase in braced frame with concentrically braces’’, First International Congress on Seismic Retrofitting, Amirkabir University of Technology, Tehran, Iran, 2006.

فایل ها

هم رسانی

ارجاع به این مقاله

آمار