Theoretical and Numerical Studies on Seismic Performance of Fully Prefabricated Liftable Inter‐Module Connections

Modular steel structures are a typical prefabricated form of assembled construction, and are increasingly recognized as a cornerstone of China's construction industrialization due to their high construction efficiency and environmental sustainability. The mechanical performance of inter‐module connections is critical to the overall seismic behavior of a structure. This study proposes a Fully Prefabricated Liftable Connection (FPLC) for modular steel structures. Quasi‐static tests were conducted on two full‐scale specimens to explore failure mechanisms, hysteresis characteristics, and energy dissipation patterns of FPLC with weakening beam‐end. A refined finite element model was developed and validated against experimental results. Twelve parametric models were generated to explore the influence of beam‐column sections and bolt configurations on the structural performance of FPLC. The analytical formulas were derived for the initial stiffness and bending capacity, together with a restoring force model. It can be concluded that the enhanced beam section significantly improves load‐bearing and energy dissipation capacities with acceptable ductility reductions, while the weakening beam‐end increases energy dissipation efficiency. The proposed theoretical formulas can provide guidance for engineering design of FPLC.