Toughness of Submerged Arc Weld Metal and Plastic Deformation Capacity of Pre-assembled Type Beam-End Connection Using Built-Up H-Shaped Beam

In Japan, built-up H-shaped beams pre-assembled by submerged arc welding (SAW) are often used for steel buildings. In this paper, the influences that the toughness of SAW metal gave on the plastic deformation capacity of the beam-end connection were investigated. The beam-end connection has scallops which the shape was a compound circle with 35R and 10R typically in Japan. Regarding the toughness of SAW metal, the influence of the welding construction conditions was investigated for two kinds of weld metals. One was a fillet weld metal by one-pass of tandem electrodes SAW, the other was a weld metal by multiple layers and passes of single electrode SAW conforming to JIS. The test results showed that the toughness of the fillet weld metal was lower than that of the JIS weld metal. The toughness of SAW metal depended on the basicity of flux. Regarding the structural characteristics of the beam-end connection, the influence of the toughness of SAW metal was investigated by the full-scale cyclic loading test. Three specimens were provided, Charpy absorbed energy at 0° (vE0) of SAW metal was 15 J, 48 J, and 59 J. As test results, the brittle fracture which the starting point of ductile crack was the bottom of scallop occurred at SAW of all specimens. The plastic deformation capacity of the beam-end connection of the vE0 = 15 J specimen was about 30% of that vE0 = 48 J and 59 J specimens.