Analytical study of unstiffened extended end-plate connections produced from austenitic stainless steel

Based on the numerical data of 66 unstiffened stainless steel beam-to-column extended end-plate (EEP) joints, a straightforward analytical method, for predicting the moment-rotation (M-Φ) response of this connection type, was developed and validated. The joint configurations employed to formulate the analytical equations cover a broad range of parameters having significant influence on the performance of this connection typology widely-utilized in steel buildings in seismic zones. To derive the equations, Richard and Abbott expression for the relationship between the moment and rotation, was adopted. This expression takes into account the strain-hardening characteristics and thus is capable of accurately predicting the response of ductile materials having considerable strain hardening such as stainless steel. The results showed that the proposed analytical model has been able to provide accurate predictions of the moment-rotation behavior of connections, with an average error less than 5% in estimating the maximum moment capacity. Finally, an additional evaluation of the suggested model was performed using finite element results for connection configurations other than those used in the calibration of the model. The further assessment demonstrated the high level of accuracy of the developed formulas over a wide range of parameters’ values. These suggested formulas can act as a simple analytical technique for predicting the entire moment-rotation response of unstiffened stainless steel EEP joints, using readily-obtainable geometric and material parameters