Structural performances investigation of seismic retrofitting of moment resisting frame with linked-column frame

This study investigates the seismic performance of reinforced concrete frames retrofitted with a novel link beam system using numerical modeling and finite element analysis. The research focuses on evaluating the response modification factor (R factor) for structures with and without retrofitting, emphasizing the influence of ductility, redundancy, overstrength, and damping factors. Numerical models of 3- and 6-story reinforced concrete frames, both retrofitted and non-retrofitted, were analyzed to assess the performance under seismic loading. Results demonstrate a significant improvement in the ductility and energy dissipation of the retrofitted frames, with increases in deformation capacity by factors of approximately 3.54 and 4.42 for the 3- and 6-story models, respectively. The average value of the R factor in the limit state design method for the numerical models 3- and 6-story of the reinforced concrete frame retrofitted with the linked column frame system achieved about 8.01 and 8.48, respectively. Also, the R factor compared to the primary frame (without retrofitting) increased about 72% and 68%, respectively. Additionally, the study finds that the retrofitted frames exhibit enhanced elastic stiffness and better seismic response, confirming the effectiveness of the linked column frame system in improving structural resilience. The findings contribute to a deeper understanding of the response modification factor and offer practical insights for optimizing seismic retrofitting strategies.