Analytical model for the progressive collapse resistance of a novel fully assembled concrete beam‐column substructure with bolted flange connections

Abstract This study develops an analytical model to characterize the progressive collapse resistance of a novel fully assembled concrete beam‐column substructure with bolted flange connections. The model, which idealizes the bolts as an equivalent continuous section to determine the rotational response and incorporates the hardening behavior arising from the elasto‐plastic deformation of the steel connectors, establishes the deformation compatibility relationship among the side column, steel connectors, and the prefabricated concrete beam. By introducing a bolt fracture criterion, the model enables precise identification of the mechanisms precipitating substructure failure. The predicted vertical load–displacement response and the evolution of internal forces at the critical sections show close agreement with the test results and finite element simulations. The validated model is subsequently employed to elucidate the mechanisms of internal force redistribution during both the flexural‐compressive arch action and catenary action stages, and to propose corresponding design recommendations. Finally, the effects of different parameters on the peak loads at various resistance stages are evaluated.