This paper presents an experimental and analytical assessment of the performance of steel beam-column assemblies with two types of moment-resisting connections under vertical displacement of a center column, simulating a column removal scenario. The connections considered include (1) a welded, unreinforced flange, bolted web connection and (2) a reduced beam section connection. The test configuration in both cases consisted of two beam spans and three columns. The two exterior column bases were anchored to the strong floor of the testing laboratory, and two diagonal braces were rigidly attached to the top of each exterior column. A downward vertical displacement of this column was imposed using a hydraulic ram, to simulate a column removal scenario. Load was applied under displacement control until connection failure occurred. The study provides insight into the behavior and failure modes of the connections, including their ability to carry tensile forces that develop in the beams. Both detailed and reduced finite element models of the connections are developed that capture the primary response characteristics and failure modes. The detailed models are capable of resolving the nonlinear behavior and failure in great detail, while analyses with the reduced models can be executed much more rapidly, facilitating implementation in models of entire structural systems. Good agreement is observed between the experimental and computational results, providing validation for the detailed and reduced models.
Proceedings Title: Proceedings of the ASCE Structures Congress 2009
Conference Dates: April 29-May 2, 2009
Conference Location: Austin, TX
Pub Type: Conferences
Finite Element Analysis, Progressive Collapse, Robustness, Steel Connections, Structural Testing