Cyclic Testing of Moment Connections Upgraded with Weld Overlays

Abstract

Experimental studies were conducted to investigate the application of fracture tough overlay welds for the upgrading of welded steel moment connections. The experimental program consisted of cyclic tests on three exterior connection specimens that were initially fabricated using pre-Northridge welding procedures. Two specimens were fabricated from small size sections and one was fabricated from an intermediate size section. Overlay welds were placed using self-shielded flux core arc weld (FCAW-ss) with a fracture tough electrode (E70T-8). The application of weld overlays to the small size specimens resulted in a significant improvement in their cyclic performance. The plastic rotation capacity of both specimens was either close to or exceeded 3%. The application of weld overlays to the moment connection of the intermediate size specimen also improved the rotation capacity. However, the upgraded specimen failed in the parent material of the beam flange, away from the weld region at a plastic rotation of 2.7%.