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Abstract
One of the most commonly used connection types in steel frame buildings is a shear connection. These connections are typically designed only for vertical shear, though previous studies have proven that shear connections have some capability to resist an interaction of shear, axial, and moment. With recent events such as the Murrah Federal Building and the World Trade Center disasters, there is a continuing need to study the robustness of connections subject to unanticipated loading scenarios.
The purpose of this research is to qualitatively and quantitatively measure the effects of the interaction of forces during a quasi-dynamic loading of a flexible WT connection. Results from this research show how a WT connection will perform during a sudden collapse of an interior support column in a steel framed building. Through the study, the robustness of the connection through both rotation and accrual of load was observed and recorded. Results of the test demonstrated the flexural resistance of the WT connection and the presence of catenary action.
To properly study and analyze the connection, physical testing of three-, four-, and five-bolt configurations of WT connections was performed. For each of the configurations, one test was loaded under a quasi-static loading rate, and three tests were loaded under quasi-dynamic loading rate. Data collected from the testing were used to calculate forces at the connection, including shear, axial, and moment.
Testing showed that as the number of bolts increased, the flexural capacity of the connection increased but the amount rotation before failure decreased. To better compare results of the two different loading types, a comparison of energy absorbed by the connection was performed. Testing showed that as the loading rate increased the net amount of rotation the connection can withstand decreases.