Blind bolted T-stub connections to unfilled hollow section columns in low rise structures

This paper presents the results of an experimental program investigating blind bolted T-stub connections to unfilled hollow section columns in the tension and compression regions under static loading. The T-stub connection is proposed as an alternative connection to the welded connection currently used as a moment connection for unfilled hollow section columns in the Australian construction industry. The flexural performance of the T-stub connection, in terms of stiffness, has been evaluated in accordance with EC3 classifications and was found to behave as a semi rigid connection under serviceability loading. Results from the experiments have been compared with existing theoretical models that predict the maximum load the flexible column face can carry in the tension region before yielding occurs, and good agreement has been achieved. Furthermore, the experimental results have been used to validate a detailed three dimensional finite element (FE) model which simulates the proposed connection. The developed FE model in turn has been used to perform a sensitivity analysis which is presented in this paper.