탄소강 용접접합부의 모재블록전단내력에 관한 실험적 연구

Abstract

An experimental study on the ultimate behaviors of the mild carbon steel (SPHC) fillet-welded connection is presented in this paper. Seven specimens were fabricated by the shielded metal arc welding (SMAW). All specimens failed by typical block shear fracture in the base metal of welded connections not weld metal. Block shear fracture observed in the base metal of welded connection is a combination of single tensile fracture transverse to the loading direction and two shear fractures longitudinal to the loading direction. Test strengths were compared with strength predictions by the current design equations and suggested equations by previous researchers. It is known that current design specifications (AISC2010 and KBC2016) and Oosterhof & Driver's equation underestimated overly the ultimate strength of the welded connection by on average 44%, 31%, respectively and prediction by Topkaya’s equation was the closest to the test results. Consequently, modified equation is required to be proposed considering the stress triaxiality effect and material property difference on the block shear strength for base metal fracture in welded connections fabricated with mild carbon steel.