Abstract
Subassemblage tests were conducted on steel beam to concrete filled square steel tube (CFT) column moment connections to investigate the structural behavior of electroslag welding connections between internal diaphragms and steel tube. The writers propose an ultimate strength equation for these connections, based on combined stresses on a fracture line within the steel plate of the CFT column. They have already proposed a model for a load-displacement relation for predicting the local tensile elasto-plastic behavior of CFT column to steel beam moment connections using internal diaphragms. This paper proposes an improved load-displacement relation model for these connections including an ultimate strength equation for electroslag welding connections in the load-displacement relation model. The improved model is found to agree approximately with this experimental result up to large deformations.
