The Behavior of Steel Bolted Beam-Column Connection under Blast Load

Abstract

Beam-column connections are one of the most critical components of steel structures. They are responsible for transferring the loads from the beams to the columns, and ensuring that the structure remains stable and strong under all loading conditions. This research investigated numerically using the Finite Element Method (FEM) the effect of blast load on a steel beam-column connection. The beam-column connection consists of an I-beam column with a length of 1500 mm and an I-beam beam with a length of 500 mm. The column and the beam are connected together through a steel plate of thickness 10 mm. The plate is welded to the beam and connected to the columns by 4 ordinary bolts of diameter 16 mm. The Coupled Eulerian-Lagrangian (CEL) modeling technique found in Abaqus/CAE was used to perform the analysis. Lagrangian elements were used to simulate the steel elements and bolts. The Eulerian elements were used to model Trinitrotoluene (TNT) and the surrounding air. A parametric study has been performed for the beam-column connection. The TNT charges were placed at a standoff distance from the center front of the connection on the same level as the bottom surface of the column. TNT charges of 10 kg, 50 kg, and 1000 kg with standoff distances of 2.5 m, and 5 m have been used in the analysis. Analysis has been performed to study the deformation, stresses, and damage of the connection. The results showed that blast load has a major impact on steel bolted beam-column connections as they could destroy the connecting bolts or even completely destroy the connection. Also, TNT charges of less than 10 kg and a standoff distance of more than 5 m have a minor effect on steel bolted beam-column connection. While, TNT charges of more than 1000 kg and a stand-off distance of less than 5 m cause a catastrophic damage and could completely destroy steel bolted beam-column connection. Moreover, the connecting bolts are the weakest link in steel bolted beam-column connections subjected to blast load as they could be damaged even when subjected to small TNT charges.