WELDED INTERIOR BOX-COLUMN TO I-BEAM CONNECTIONS

This paper deals with experimental investigations to study the ultimat e load behavior of I-beam to box-column connections stiffened external ly. Specimens representative of interior columns in a steel building f rame were fabricated with connections stiffened by T-sections butt-wel ded at the junction of the beam and column flange. They were tested to failure under static and fluctuating loads applied separately. Ultima te load-carrying capacity and typical load-deflection and moment-rotat ion responses obtained experimentally are presented; the results for t hose specimens tested under static loading are compared with the corre sponding results using the elasto-plastic finite-element method. Close agreement is observed between the experimental and theoretical moment -rotation curves. Results show clearly that these connections satisfy the basic criteria: sufficient strength, sufficient rotation capacity, and adequate stiffness for a moment connection. The proposed connecti ons are capable of developing load-carrying capacity in excess of the plastic capacity of the beams framing into the joint.