建築鉄骨柱梁溶接部における継手性能に溶接多重熱サイクルが及ぼす影響

－溶接継手の継手性能と溶接熱サイクルの関係に関する研究（第1報）－

抄録

The characteristics of welded joint like as tensile strength or fracture toughness depend on welding conditions and multiple welding heat cycles particularly affect the joint performance. The effects of heat input and interpass temperature at multi-pass welded joint of beam-to-column connections on the strength and fracture are investigated in this paper. Tensile test, Charpy impact test, and three-point bending CTOD test are performed by using welded joint specimen fabricated with various welding conditions. The results of experiments actually show that there exists a welding condition which decreases joint performance. Three-dimensional thermal elastic-plastic finite-element analysis is also performed by using the moving heat source and with phase transformation effect. The parameters of heat input, interpass temperature, and welding direction are changed in the analyses, and the results are used for the consideration of the effect of multiple heat cycles on joint performance. The analytical and the experimental results are shown that controlling heat input and interpass temperature is much important to assure the quality of welded joints in beam-to-column connections of steel framed structures.