NIST logo

Publication Citation: Cyclic Testing of Steel Moment Frame Connections Rehabilitated with RBS or Welded Haunch

NIST Authors in Bold

Author(s): C M. Uang; Q -. Yu; S Noel; John L. Gross;
Title: Cyclic Testing of Steel Moment Frame Connections Rehabilitated with RBS or Welded Haunch
Published: January 01, 2000
Abstract: The effectiveness of using the reduced beam section (RBS) and welded haunch for seismic rehabilitation of pre-Northridge steel moment connections was investigated through cyclic testing of six full-scale specimens-three of them incorporated lightweight concrete slabs. Test results showed that, unless the low-toughness E70T-4 groove weld was replaced by notch-tough weld metal, introducing RBS to the bean bottom flange alone could not prevent brittle fracture in the groove weld of the top flange. The presence of a concrete slab or removing steel backing only improved the cyclic performance slightly. Although two RBS specimens with weld replacement performed well, a new type of ductile fracture along the k line of the beam was observed. With E70T-4 groove welds in place, however, the welded haunch specimens performed better than the RBS specimens. No brittle fracture occurred when the slab was present. The composite slab only increased the beam positive flexural strength by about 10%.
Citation: Journal of Structural Engineering-ASCE
Volume: 126
Issue: No. 1
Pages: pp. 57 - 68
Keywords: concrete;concrete slab;cyclic testing;RBS;reduced beam section;steel moment connections;welded haunch
Research Areas: Building and Fire Research
PDF version: PDF Document Click here to retrieve PDF version of paper (844KB)