Moment Resistance of Steel I-Beam to CFT Column Connections

Abstract

This paper focused on investigating the moment resistance of steel I-beam to concrete-filled tube (CFT) column uniplanar connections under monotonic static loading. The composite connection can be stiffened or unstiffened. An empirical formula was derived based on >100 numerical parametric analysis results. The key parameters were studied numerically by finite-element method and the relevant ones that affect moment resistance were captured in the proposed formula. To verify the empirical formula and understand clearly the static behavior of the composite connections, eight specimens were designed and tested to failure, of which four specimens were semirigid beam-to-column connections and others were rigid connections with different types of stiffening details. The comparison between the predictions and test results showed that the empirical formula could be used to predict the moment resistance. The proposed rebar stiffener was found to be very effective in improving the static behavior of the composite connections.