Seismic behavior of high-performance steel (HPS) weakened beam-column joints: Experimental tests and numerical analysis

This paper experimentally and numerically investigates the seismic behavior of high-performance steel (HPS) weakened beam-column joints. Three different geometrical configurations of weakened joints were designed, and experimental tests were conducted under cyclically varying lateral load. The test results revealed that the connection type had a significant influence on the seismic behavior of the joints. The specimen JD-2 exhibited excellent ductility and energy dissipation capacity. Moreover, the seismic behavior of specimen JD-3 was significantly improved due to the existence of transition plates, and its energy dissipation efficiency was 1.25 times that of the prototype specimen JD-1. Additionally, the relationship between the development of damage and the various mechanical response of each joint was discussed based on the model proposed by Krawinkler and Zohrei. Detailed finite element (FE) model were then developed and validated. The benchmarked models were utilized to evaluate the seismic behavior of HPS joints, including stiffness and strength degradation, energy dissipation, ductility coefficient, and damage evolution. Based on the experimental tests and FE analysis, a new trilinear hysteretic model considering damage development was proposed, which was in good agreement with the test results. It is indicated that the simplified model can effectively capture the seismic behavior of HPS weakened beam-column joints under cyclic loading conditions.