Methodology for Predicting the Alternate Block Shear Failure of Beams in Bolted Flange Plate and Double Tee Moment Connections

  • Mazen B. Helwe
  • Elie G. HantoucheEmail author


This study investigates the alternate block shear (ABS) failure in bolted flange plate (BFP) and double Tee moment connections. ABS, not yet included in the AISC 358 specifications, is a failure mode that combines full tensile fracture in the beam flange with shear failure in the beam web. After validation with experimental results, finite element (FE) models are developed to examine ABS failure in BFP and double Tee moment connections. The dimensionless ratio of connection length to beam depth ratio is considered the major parameter for identifying the governing failure mode. Experimental results available in the literature and FE results conducted in this study are compared with existing strength models to investigate their prediction capabilities. A proposed methodology is presented through a stiffness based model to predict the failure path and mode. Adding the ABS failure check to the current US building standards is recommended to ensure a safe design.


Alternate block shear Bolted flange plate Double Tee Design Stiffness model 



  1. American Institute of Steel Construction (AISC). (2016). Specification for structural steel buildings. ANSI/AISC 360-16, Chicago, IL.Google Scholar
  2. American Institute of Steel Construction (AISC). (2016). Prequalified connections for special and intermediate steel moment frames for seismic applications. ANSI/AISC 358-16, Chicago, IL.Google Scholar
  3. Cai, Q., & Driver, R. (2010). Prediction of bolted connection capacity for block shear failures along atypical paths. Engineering Journal, 47, 213–221.Google Scholar
  4. Driver, R., Gordin, G., & Kulak, G. (2006). Unified block shear equation for achieving consistent reliability. Constructional Steel Research, 62, 210–222.CrossRefGoogle Scholar
  5. Epstein, H. (1996). Block shear of structural tees in tension-alternate paths. Engineering Journal, 33, 228–239.Google Scholar
  6. Epstein, H., & McGinnis, M. (2000). Finite element modeling of block shear in structural tees. Computers & Structures, 77, 571–582.CrossRefGoogle Scholar
  7. Epstein, H., & Stamberg, H. (2002). Block shear and net section capacities of structural tees in tension: Test results and code implications. Engineering Journal, 39, 228–239.Google Scholar
  8. European Committee for Standardization (CEN). (2005). Eurocode 3: Design of steel structures—Part 1–8: Design of joints and building frames. BS EN 1993-1-8, Brussels.Google Scholar
  9. Hantouche, E. (2011). Behavior of thick flange built-up T-stub connections for moment resisting frames. Cincinnati, Ohio: University of Cincinnati.Google Scholar
  10. Hantouche, G., & Jaffal, H. (2016). Design of thick plate double-tee connections for seismic applications. Practice Periodical on Structural Design and Construction, 21(4), 04016013.CrossRefGoogle Scholar
  11. Sato, A., Newel, D., & Uang, C. (2008). Cyclic behavior and seismic design of bolted flange plate steel moment connections. Engineering Journal, 45, 221–232.Google Scholar
  12. Wuwer, W., Zamorowski, J., & Swierczyna, S. (2012). Lap joints stiffness according to Eurocode EC3 and experimental investigations results. Archives of civil and Mechanical Engineering, 12, 95–104.CrossRefGoogle Scholar

Copyright information

© Korean Society of Steel Construction 2019

Authors and Affiliations

  1. 1.Department of Civil and Environmental EngineeringAmerican University of BeirutRiad El-Solh, BeirutLebanon

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