오스테나이트계 스테인리스강은 우수한 내식성, 내구성 및 내화성을 지닌다. 특히, 오스테나이트계 스테인리스강중의 대표인 STS304에 비해 저탄소를 함유하고 있는 STS304L은 현장용접 후 별도의 열처리 없이 높은 내입계부식성능을 지니고 있어 용접후 내입계 부식이 우려되는 부재접합에 적용할 수 있다. 본 연구에서는 티그(TIG)용접으로 필릿 용접된 STS304L 용접접합부의 용접재(용착금속부) 내력과 파단 메카니즘을 조사하고자 한다. 주요변수인 하중방향에 대한 용접선의 배치에 따라 TFW(하중직각방향 용접), LFW(하중방향용접), FW (하중방향용접과 하중직각방향 용접조합)시리즈의 실험체를 제작하여 인장실험을 실시하였고, 각각 인장파단,전단파단, 블록전단파단(인장 파단과 전단파단의 조합)이 발생하였다. 동일 용접길이에 대해 TFW 시리즈의 접합부가 가장 높은 내력을 나타났으며, 현행기준식( KBC2016/AISC2010)과 기존 연구자의 식에 의한 예측내력과 비교한 결과, TFW와 LFW접합부는 과소평가되었고 FW실험체는 과대평가되었다 .실제 파단 위험단면과 블록전단파단 메카니즘을 고려한 내력식을 제안하였다.

This study focused on the ultimate behaviors(ultimate strength and fracture mode ) of single shear bolted connection with austenitic sainless steel(STS201) and curling effect on the ultimate strength using finite element analysis based on test results. Main variables are end distance in the parallel direction to loading and edge distance in the perpendicular direction to loading. The validation of finite element analysis procedures was verified through the comparisons of ultimate strength, fracture mode and curling(out-of-plane deformation) occurrence between test results and numerical predictions. Curling was observed in both test and analysis results and it reduced the ultimate strength of single- shear bolted connections with relatively long end distances. Strength reduction ratios caused by curling were estimated quantitatively by maximum 19%, 32%, respectively for specimens with edge distance, 48 mm and 60 mm compared with strengths of uncurled connections with restrained out-of-plane deformation. Finally, analysis strengths were compared with current design strengths and it is found that design block shear equations did not provide the accurate predictions for bolted connections with strength reduction by curling.

In this paper, block shear fracture behavior in base metal of fillet-welded connection fabricated with duplex stainless steel (STS329FLD) were investigated through experimental procedures. Main variables are weld lengths in the longitudinal and the transverse directions of applied force. As a result, test specimens failed by typical block shear facture (the combination of tensile fracture and shear-out fracture) in base metal not weld metal. Ultimate strength of the specimens tended to get higher with the increase of the weld lengths.

Recently, the use of duplex stainless steel which has a two-phase microstructure consisting of grains of ferritic and austenitic stainless steel has been increased in a variety of industrial fields. Especially, STS329FLD with lower nickel content and higher yield strength compared with austenitic stainless steel has been developed. In this paper, experiments have been conducted to investigate the structural behaviors of single shear duplex stainless steel(STS329FLD) bolted connection with four bolts. Specimens with relatively long end distance failed by block shear fracture accompanied with curling (out-of-plane deformation) and the curling reduced the ultimate strength.

This study investigates structural behaviors such as ultimate strength and weld metal fracture mechanism of carbon steel (SS400) fillet-welded connections with shielded metal arc welding (SMAW) through monotonic tensile test. Specimens of TFW series (transverse fillet weld against loading direction) and LFW series (longitudinal fillet weld) failed by tensile fracture and shear fracture, respectively in the weld metal of connections. Test strengths of specimens were compared according to welding direction and weld length.

This paper deals with block shear fracture behavior in base metal of carbon steel welded connection. Monotonic tensile experiments have been conducted to investigate the structural behaviors of carbon steel fillet-welded connection with the block shear fracture in base metal. Main parameters are weld lengths in the longitudinal and transverse directions of applied force. Finite element analysis in this paper focused on the ultimate strength and fracture mode of welded connections. It was shown that predictions by finite element analysis method were in a good correspondence with test results for ultimate behaviors such as fracture mode and ultimate strength.

Ultimate behaviors such as ultimate strength and fracture mechanism of fillet-welded connections with TIG(tungsten inert gas) welding have been investigated through test results. Main variables of specimens are weld length and welding direction against loading and ultimate strengths were compared according to the variables. Ultimate strengths were compared with current design predictions and modified design equations were proposed to consider the strength difference according to welding direction.

Austenitic stainless steels have excellent corrosion resistance, durability, aesthetic appeal, fire resistance etc. compared with ferritic stainless steels and so especially 304 stainless steels have been utilized widely in the exterior member of building structure. In this paper, ultimate behaviors such as ultimate strength and fracture mechanism of fillet-welded connections with TIG(tungsten inert gas) welding have been investigated through test results. Main variables of specimens are weld length and welding direction against loading and ultimate strengths were compared according to the variables.