2행1열 듀플렉스계 스테인리스강(STS329FLD) 볼트접합부의 최대내력 조사

초록

Recently, the use of duplex stainless steel which with a two-phase microstructure (equal mixture of ferrite and austenite) has been increasedin a variety of industrial fields due to higher strength leading to weight saving, greater corrosion resistance(particularly, stress corrosion cracking) andlower price. However, currently, stainless steels are not included in the structural materials of Korean Building Code and corresponding design standardsare not specified. In this paper, experimental studies have been performed to investigate the structural behaviors of duplex stainless steel (STS329FLD)bolted connection with two bolts for providing the design data. Main variables are shear connection type (single shear and double shear) and end distanceparallel to the direction of applied force. Fracture modes at the final step of test were classified into typical block shear fracture, tensile fracture andcurling. Curling occurrence in single shear connection led to ultimate strength drop by up to 20%. Test strengths were compared with those by currentdesign specifications such as AISC/AISI/KBC, EC3 and AIJ and proposed equations by existing studies. For specimens with no curling, Clement &Teh's equation considering the active shear plane provided a higher strength estimation accurancy and for specimens with curling, Kim & Lim's equationconsidering strength reduction by curling was also overly unconservative to predict the ultimate strength of curled connections.

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