Skip to main content
Log in

Improved design of drilled flange (DF) moment resisting connection for seismic regions

  • Original Research Paper
  • Published:
Bulletin of Earthquake Engineering Aims and scope Submit manuscript


Reduced beam section (RBS) connection was developed as an authentic alternative for welded unreinforced flange connections to prevent the wide spread typical damage of the beam to column welded connections observed after the 1994 Northridge earthquake. Drilled flange (DF) connection, as the next generation of RBS connection, was developed to replace the former RBS connection, due to their easier construction. The present study aims to investigate the effects of different design parameters such as center-to-center distance of the drilled holes, drilled holes diameter, row number of the drilled holes and beam span-to-depth ratio on seismic performance of DF connection. For this purpose, experimentally validated detailed finite element models (FEMs) are used. Also, the cyclic responses of FEMs are utilized to validate the proposed closed-form equations for estimating the yield moment and plastic moment capacity of DF connection. The results indicate that placing the specified limits on the latter design parameters can reduce equivalent plastic strain and Rupture Index at CJP groove weld line of DF connection up to 100 and 154%, respectively. Furthermore, based on the analytical results, the proposed closed-form equations can predict the plastic moment capacity and the yield moment of DF connection with the maximum errors bound less than 8 and 9%, respectively. The results of this study provide the practical recommendations for DF connection seismic design.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17
Fig. 18

Similar content being viewed by others


  • AISC (2015) Seismic provisions for structural steel buildings, AISC 341-16. American Institute of Steel Construction, Chicago

    Google Scholar 

  • AISC (2016a) Prequalified connections for special and intermediate steel moment frames for seismic applications, AISC 358-16. American Institute of Steel Construction, Chicago

    Google Scholar 

  • AISC (2016b) Specification for structural steel buildings, ANSI/AISC 360-16. American Institute for Steel Construction, Chicago

    Google Scholar 

  • ANSYS (1998) User’s manual. Version 5.4, 201. ANSYS Inc, Houston

    Google Scholar 

  • Atashzaban A, Hajirasouliha I, Ahmady Jazany R, Izadinia M (2015) Optimum drilled flange moment resisting connections for seismic regions. J Constr Steel Res 112:325–338.

    Article  Google Scholar 

  • ATC (1992) Guidelines for cyclic seismic testing of components of steel structures, ATC 24. Applied Technology Council

  • Deylami A, Moslehi Tabar A (2013) Promotion of cyclic behavior of reduced beam section connections restraining beam web to local buckling. Thin Walled Struct 73:112–120.

    Article  Google Scholar 

  • DIN (1995) Hot rolled I and H sections: dimensions, mass and static parameters, DIN 1025. DIN, Berlin

    Google Scholar 

  • DIN Steel Standard (2011) Steels for general structural purposes, DIN 17100, Germany Steel Grades

  • Elkady A, Lignos D (2015) Analytical investigation of the cyclic behavior and plastic hinge formation in deep wide-flange steel beam-columns. Bull Earthq Eng 13(4):1097–1118.

    Article  Google Scholar 

  • El-Tawil S, Mikesell T, Vidarsson E, Kunnath S (1998) Strength and ductility of FR welded bolted connections. Report no. SAC/BD-98/01, SAC Joint Venture, Sacramento, CA

  • Engelhardt MD, Fry G, Johns S, Venti M, Holliday S (2000) Behavior and design of radius cut, reduced beam section connections. Report no. 00/17, SAC, California

  • Farrokhi H, Danesh F, Eshghi SA (2009) Modified moment resisting connection for ductile steel frames (numerical and experimental investigation). J Constr Steel Res 65(10–11):2040–2049.

    Article  Google Scholar 

  • FEMA (2000) State of the art report on connection performance. Report no. FEMA-355D, Federal Emergency Management Agency, Washington

  • FEMA (2000) Prestandard and commentary for the seismic rehabilitation of buildings. Report no. FEMA-356, Federal Emergency Management Agency, Washington

  • Ghassemieh M, Kiani J (2013) Seismic evaluation of reduced beam section frames considering connection flexibility. Struct Des Tall Spec Build 22:1248–1269.

    Google Scholar 

  • Han SW, Kim NH (2017) Permissible parameter ranges of access hole geometries for WUF-W connections. J Earthq Spectr 33(2):687–707.

    Article  Google Scholar 

  • Hancock JW, Mackenzie AC (1976) On the mechanisms of ductile failure in high strength steels subjected to multi-axial stress states. J Mech Phys Solids 24:147–169.

    Article  Google Scholar 

  • Hodge PG (1959) Plastic analysis of structures. McGraw-Hill, New York

    Google Scholar 

  • Iannone F, Latour M, Piluso V, Rizzano G (2011) Experimental analysis of bolted steel beam-to-column connections: component identification. J Earthquake Eng 15(2):214–244.

    Article  Google Scholar 

  • Inglis CE (1913) Stresses in plates due to the presence of cracks and sharp corners. Trans Inst Nav Archit 55:219–242

    Google Scholar 

  • Irwin GR (1957) Analysis of stresses and strains near the end of a crack traversing a plate. J Appl Mech 24(3):361–364

    Google Scholar 

  • Kanvinde AM, Deierlein GG (2005) Continuum based micromodels for ultra low cycle fatigue crack initiation in steel structures. In: Proceedings of the structures congress and exposition. ASCE, Reston, VA

  • Kanvinde AM, Deierlein GG (2007) A cyclic void growth model to assess ductile fracture in structural steel due to ultra low cycle fatigue. J Eng Mech 133(6):701–712.

    Article  Google Scholar 

  • Kim DW, Ball SC, Sim HB, Uang CM (2016) Evaluation of sloped RBS moment connections. J Struct Eng ASCE.

    Google Scholar 

  • Lee SJ, Noh SE, Han SY, Shin SW (2007) Deformation capacity of reduced beam section moment connection by staggered holes. In: International conference on sustainable building, Seoul, Korea

  • Mallik PK (1988) Effect of holes stress concentration on tensile strength of sheet modeling compound (SMC-50) composites. Composites 19(4):283–287.

    Article  Google Scholar 

  • Myers A, Kanvinde A, Deierlein G, Baker J (2014) Probabilistic formulation of the cyclic void growth model to predict ultralow cycle fatigue in structural steel. J Eng Mech 140(6):04014028.

    Article  Google Scholar 

  • Pachoumis DT, Galoussis EG, Kalfas CN, Christitsas AD (2009) Reduced beam section moment connections subjected to cyclic loading: experimental analysis and FEM simulation. J Eng Struct 31(1):216–223.

    Article  Google Scholar 

  • Popov EP, Yang T, Chang S (1998) Design of steel MRF connections before and after 1994 Northridge earthquake. Eng Struct 20(12):1030–1038.

    Article  Google Scholar 

  • Rahnavard R, Hassanipour A, Siahpolo N (2015) Analytical study on new types of reduced beam section moment connections affecting cyclic behavior. Case Stud Struct Eng 3:33–51.

    Article  Google Scholar 

  • Roeder CW (2002) Connection performance for seismic design of steel moment frames. J Struct Eng 128(4):517–525.

    Article  Google Scholar 

  • SAC (2000) Search connection database.

  • Shaikh AF, Fattah A (1978) Proposed revisions to shear-friction provisions. PCI J 23(2):12–21

    Google Scholar 

  • Tsai KC, Chen CY (1996) Performance of ductile steel beam-column moment connections. In: 11th world conference on earthquake engineering, Acapulco, Mexico

  • Vetr M, Haddad A (2010) Study of drilled flange connection in moment resisting frames. Report no. 3732, International Institute of Earthquake Engineering and Seismology, Tehran, Iran

  • Vetr M, Miri M, Haddad A (2012) Seismic behavior of a new reduced beam section connection by drilled holes arrangement (RBS_DHA) on the beam flanges through experimental studies. In: 15th world conference of earthquake engineering, Lisbon, Portugal

  • Wahl AM, Beeuwkes R (1934) Stress concentration produced by holes and notches. Trans ASME Appl Mech Sect 56:617–623

    Google Scholar 

  • Wang Y, Zhou H, Shi Y, Xiong J (2011) Fracture prediction of welded steel connections using traditional fracture mechanics and calibrated micromechanics based models. Int J Steel Struct 11(3):351–366.

    Article  Google Scholar 

  • Youssef NFG, Bonowitz D, Gross JL (1995) A survey of steel moment resisting frame buildings affected by the 1994 Northridge earthquake. Report no. NISTIR5625, NIST, Gaithersburg, MD

Download references


This study was supported by Department of Civil Engineering, East Tehran Branch, Islamic Azad University (IAU) (Grant No. 1295). Great appreciation should be expressed to all staff at the AIU. This study could not have been completed without the valuable help of these colleagues.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Roohollah Ahmady Jazany.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Ahmady Jazany, R. Improved design of drilled flange (DF) moment resisting connection for seismic regions. Bull Earthquake Eng 16, 1987–2020 (2018).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: