Research on the Restoring Force Model for T-Stub Connected Beam-Column Joints

To investigate the seismic performance of T-stub connected beam-column joints， quasi-static loading tests were conducted on two T-stub joint specimens. Key mechanical indicators， including hysteretic curves， skeleton curves， and failure modes， were obtained. Based on the shape characteristics of the skeleton curves， a simplified skeleton curve model was proposed for this joint type. The mechanical parameter calculation method for the simplified model was established through mechanism analysis and the small deformation superposition principle. By performing regression analysis on experimental data from this study and joint test data from existing literature， the hysteretic rule expression was fitted and the restoring force model for such joints was developed. The validity of the proposed model was verified through a comparative analysis between theoretical calculations and experimental results. Research findings demonstrate that T-stub connected beam-column joints exhibited typical semi-rigid connection behavior with favorable seismic performance. The established restoring force model demonstrated high computational accuracy， making it suitable for seismic performance analysis and evaluation of this type of joint.