ABSTRACT
Bolted beam-to-diaphragm connections are often critical sections to under earthquake stresses. The Architectural Institute of Japan (AIJ) has recommended a coefficient for joints as a safety factor: αy = 1.0 to allow beam yield and αu = 1.10∼1.25 to prevent rupture. However, the target for these coefficients is beam-to-beam joints subject to comparatively small stresses in welded diaphragm connections. In this study, eight cantilever-beam-type specimens incorporating bolted friction joints were cyclically loaded to determine a suitable joint coefficient to meet the AIJ recommendation. Test results and calculations led to conclusion that for grade of SS400 (mild steel), αy needs to be greater than ζ (bending moment gradient), and αu needs to be over 1.35.
