• Steel and Composite Structures
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• 제10권5호
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• pp.385-414
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• 2010

In current European Standard EN 1993, the moment-rotation characteristics of beam-to-column joints made from steel with a yield stress > 460MPa are obtained from elastic design procedures. The strength of the joint basic components, such as the column web subject to local transverse compression, is thus limited to the yield resistance rather than the plastic resistance. With the recent developments of higher strength steel grades, the need for these restrictions should be revisited. However, as the strength of the steel is increased, the buckling characteristics become more significant and thus instability phenomena may govern the design. This paper summarizes a comprehensive set of finite element parametric studies pertaining to the strength behaviour of high-strength steel unstiffened I-columns in transverse compression. The paper outlines the implementation and validation of a three-dimensional finite element model and presents the relevant numerical test results. The finite element predictions are evaluated against the strength values anticipated by the EN 1993 for conventional steel columns and recommendations are made for revising the specifications.

• 한국강구조학회 논문집
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• 제24권4호
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• pp.479-490
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• 2012

본 연구에서는 고강도 강재의 플랜지 폭두께비가 강도 및 회전능력에 미치는 영향을 분석하고자 인장강도 800MPa급 고강도 강재인 HSB800, HSA800의 조립 H형강 보에 대해 실물대실험 연구를 수행하였다. 일반강재의 실험결과를 바탕으로 정립된 현행 기준의 폭두께비 규정을 고강도 강재에 그대로 확대 적용할 수 있는지의 여부를 평가하는 것을 연구의 주 목표로 하였다. 실험결과 고강도 휨부재는 강도측면에서 매우 만족스러운 성능을 발현하였으나, 회전능력측면에서는 일반강재 대비 부족한 성능을 발휘하였다. 이러한 고강도 강재의 부족한 회전능력은 항복참(yield plateau)의 부재와 높은 항복비를 갖는 고강도강의 재료적 특성과 관련됨을 입증하였다. 잔류응력 측정결과 잔류응력의 크기는 소재의 항복강도와 무관함을 재확인 할 수 있었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.511-520
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• 2008

The steel pipe strut for a means of the retaining structure has been used generally in North America, Europe and China so far. However, Korea and Japan, two countries are much familiar with H-shape steel strut having its anisotropic strength on two different axes(named as strong and weak axes), even though they recognize the steel pipe's excellence of structural function associated with its compressive ability. This trend is mainly due to a number of its field application, accumulated know-hows and workmanship etc. This paper introduces particular features of a high-strength steel pipe strut in comparison with the H-shape steel strut and its application for two excavation sites in Seoul. As a result of field verification, the high-strength pipe steel strut is more effective than the H-shape steel strut in terms of construction costs, schedules, constructibility and structural stability.

• Steel and Composite Structures
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• 제42권6호
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• pp.827-841
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• 2022

The rotation capacities of the plastic hinges located at beam-ends are significantly reduced in traditional steel framed-tube structures (SFTSs) because of the small span-to-depth ratios of the deep beams, leading to the low ductility and energy dissipation capacities of the SFTSs. High-strength steel framed-tube structures with replaceable shear links (HSSFTS-RSLs) are proposed to address this issue. A replaceable shear link is located at the mid-span of a deep spandrel beam to act as a ductile fuse to dissipate the seismic energy in HSSFTS-RSLs. A 2/3-scaled HSSFTS-RSL specimen with a shear link fabricated of high-strength low-alloy Q355 structural steel was created, and a cyclic loading test was performed to study the hysteresis behaviors of this specimen. The test results were compared to the specimens with soft steel shear links in previous studies to investigate the feasibility of using high-strength low-alloy steel for shear links in HSSFTS-RSLs. The effects of link web stiffener spaces on the cyclic performance of the HSSFTS-RSLs with Q355 steel shear links were investigated based on the nonlinear numerical analysis. The test results indicate that the specimen with a Q355 steel shear link exhibited a reliable and stable seismic performance. If the maximum interstory drift of HSSFTS-RSL is designed lower than 2% under earthquakes, the HSSFTS-RSLs with Q355 steel shear links can have similar seismic performance to the structures with soft steel shear links, even though these shear links have similar shear and flexural strength. For the Q355 steel shear links with web height-to-thickness ratios higher than 30.7 in HSSFTS-RSLs, it is suggested that the maximum intermediate web stiffener space is decreased by 15% from the allowable space for the shear link in AISC341-16 due to the analytical results.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
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• pp.5-8
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• 2005

The purpose of this study is to investigate the mechanical characteristics of plain and steel fiber high strength concrete under uniaxial and biaxial loading condition. A number of plain and steel fiber high strength concrete cubes having 28 days compressive strength of 82.7Mpa (12,000psi) were made and tested. Four principal compression stress ratios, and four fiber concentrations were selected as major test variables. From test results, it is shown that confinement stress in minor stress direction has pronounced effect on the strength and deformational behavior. Both of the stiffness and ultimate strength of the plain and fiber high strength concrete increased. The maximum increase of ultimate strength occurred at biaxial stress ratio of 0.5 in the plain high strength concrete and the value were recorded 30 percent over than the strength under uniaxial condition. The failure modes of plain high strength concrete under uniaxial compression were shown as splitting type of failure but steel fiber concrete specimens under biaxial condition showed shear type failure.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
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• pp.603-608
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• 2001

In these days, high-strength steel prevails throughout the construction fields for the benefit of structural and economical aspects. But high-strength steel is used by the simple calculation of flexural capacities for the purpose of reducing flexural reinforcement. So, this paper is mainly focused on the shear behavior of high-strength steel reinforced concrete beams without stirrups comparing with normal-strength steel reinforced concrete beams. Specimens were made and tested with the experimental parameters, such as steel yield strength, reinforcement ratios and minimum shear reinforcement. The main result was that not only area but also the yield strength of flexural reinforcement should be considered to predict the shear capacities of concrete beams.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.401-404
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• 2009

The purpose of this study is investigating the joint characteristics of advanced high strength steel DP780 and Al5052 alloy sheet in the clinching process. It is difficult to join the advanced high strength steel with light-weight materials like aluminum alloy, because of low formability of DP780. The defects of clinching joint such as necking of the upper sheet, cracks of the lower sheet and no interlocking were occurred by different ductility between advanced high strength steel and aluminum alloy. The clinching conditions should be optimized to interlock without any defects. In this study, the effect of process parameters of clinching process on joinability of advanced high strength steel with Al5052 alloy was investigated by using FE-analysis. From the result of FE-analysis, the clearance between clinching punch and die, die depth and the shape of die cavity mainly affected the joinability of advanced high strength steel with Al5052 alloy.

• Steel and Composite Structures
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• 제11권5호
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• pp.391-402
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• 2011

It is clear from the former researches on reinforced concrete filled steel tubular (RCFT) structures that RCFT structures have higher strength and deformation capacity than concrete filled steel tubular (CFT) structures. However, in the case of actual applications to large-scaled structures, the thin-walled steel tube must be used from the view point of economic condition. Therefore, in this study, compression tests of RCFT columns which were made by thin-walled steel tube or small load-sharing ratio in cooperation with high strength concrete were carried out, meanwhile corresponding tests of CFT, reinforced concrete (RC), pure concrete and steel tube columns were done to compare with RCFT. By the a series of comparison and analysis, characteristics of RCFT columns were clarified, and following conclusions were drawn: RCFT structures can effectively avoided from brittle failure by the using of reinforcement while CFT structures are damaged due to the brittle failure; with RCFT structures, excellent bearing capacity can be achieved in plastic zone by combining the thin-walled steel tube with high strength concrete and reinforcement. The smaller load-sharing ratio can made the reinforcement play full role; Combination of thin-walled steel tube with high strength concrete and reinforcement is effective way to construct large-scaled structures.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.300-301
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• 2007

In this study, it is investigated that sheet characteristics of high strength steel sheets and effect of springback. High strength steel sheets has got attention in automobile industry of high strength and high formability. Springback is a common phenomenon in sheet metal forming, caused by the elastic recovery of the internal stresses after removal of the tooling. However, the information in deformation behavior of high strength steel sheets, including bending and sheet characteristics and springback, is not enough until now. In this research, the V-bending experiment and analysis have been done to obtain the information of springback of high strength steel sheets. Tensile test for high strength steel sheets was done to got tensile properties of elastic modulus and flow stress of the material. It analyzed springback according to the sheet characteristics with using roll-forming model. FE-Simulation used DEFORM-$3D^{TM}$.

• 한국강구조학회 논문집
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• 제13권2호
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• pp.123-131
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• 2001

본 연구의 목적은 고강도 H형강 기둥재(beam-column)의 폭두께비에 관한 기준을 조사하고 좌굴내력을 평가하여, 강구조 한계상태설계기준과 허용응력설계기준(안)과 비교함으로써, 고강도강을 사용한 기둥부재 설계시 적용된 기준식의 타당성을 검토하기 위한 것이다. 실험에 사용된 고강도강은 SM520TMC, SM570Q 등을 사용하였고, 강재의 기계적 성질과 단주의 응력-변형도 관계를 파악하기 위하여 인장시험 및 단주압축시험을 실시하였다. 또한 고강도강 기둥재의 좌굴내력을 산정하기 위하여 수치해석을 수행하였다. 수치해석에 사용된 축력-모멘트-곡률 관계는 단주압축실험에서 구해진 응력-변형도 관계를 사용하였다