Finite element analysis of steel beam to column connections subjected to blast loads

The behavior of fully restrained steel connections subjected to blast loads was examined using finite element analysis. Two connections that were tested as part of the AISC Northridge Moment Connection Test Program (Report for AISC, 1994) were studied using ABAQUS. Models were validated by comparing numerical results against AISC Program experimental data. Validated models were then subjected to simulated blast loads and their efficiency against those blast loads was verified based on criteria specified in TM5-1300 (Department of the Army, Structures to resist the effects of accidental explosions, 1990). Adequacy of TM5-1300 criteria was investigated and critical zones in the connection details were identified. Based on the results of the study, recommendations for modifications to TM5-1300 criteria were made and the effectiveness of the chosen connection details under blast loads was summarized. The results showed that the TM5-1300 criteria for steel connections subjected to blast loads are inadequate. Also the unreinforced (pre-Northridge) connection detail performed poorly under blast loads with excessive deflections and above yield stresses in the connection region while the reinforced connection detail showed improved resistance against blast loads and this connection may be an option when detailing steel framed connections to resist blast loads.