• Journal of Korean Society of Steel Construction
• /
• v.21 no.6
• /
• pp.585-596
• /
• 2009

In the construction of end-plate connections, the end-plate is welded to the end of the beam in a factory and fastened by bolts in the field. This connection is widely used in advanced countries such as European countries and the U.S. Its design and connection details are prescribed in Eurocode 3, AISC LRFD, and FEMA 350. In Korea, the standards for seismic design in KBC 2005 have been reinforced based on IBC 2000 in the U.S., and it is expected that the connection details in the U.S. will be adopted for the establishment of beam-to-column design standards. In the U.S. thick end-plates are used for the connections to prevent beam rupture. The use of the connections in Korea, however, may lead toover-design. In this experimental study, the design standards for the end-plate connections provided by FEMA-350 were analyzed and structural tests for six specimens were conducted with the variables being the shim plate and the connection shape, to provide the best specifications for connections with plastic deformation in the end-plate for use in Korea.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.8 no.2
• /
• pp.259-267
• /
• 2004

Most steel frame structures are constructed to one side without considering the arrangement of major-minor axis of column and bracing. This research presents more safety and economic efficiency can be obtained by just rearrangement of major-minor axis. Because most of steel-frame structures are excessively designed with Allowable Stress Design, and it needs to be changed to other specifications. The arrangement of major-minor axis of column is partly referred in AISC-LRFD, but still insufficient. This study compared with the each result from rearrangement of major-minor axis of column, arrangement of bracing, the connecting method of bracing, and consequence with different specifications. Moreover it demonstrated the direction of more economically optimized design.

• Journal of Korean Society of Steel Construction
• /
• v.11 no.2 s.39
• /
• pp.167-179
• /
• 1999

The thin web panels of plate girders often need to be reinforced with transverse stiffeners to increase the shear strength. Since early 1960s, extensive researches have been conducted on the ultimate shear strength of plate girder webs with transverse stiffeners. These results have been first adopted into AASHTO(1970) and British Standard(1983) Specifications for the determination of the ultimate shear strength of transversely stiffened web panels. Although the main purposes of reinforcing web panels with longitudinal stiffeners are to increase the buckling strength and to control the lateral deflections due to bending, it has been reported that the longitudinal stiffeners increase the shear strength. However lack of studies has kept the effects of the longitudinal stiffeners on the ultimate shear strength from the design of plate girder web panels. In the present study an experimental investigation is carried out in order to assess the increment of the ultimate shear strength of shear web panels due to the longitudinal stiffeners and the results are compared with the existing failure theories.

• Journal of Korean Society of Steel Construction
• /
• v.15 no.1
• /
• pp.25-31
• /
• 2003

This research aimed to experimentally and theoretically investigate the moment strength of deck plates. A moment experiment was carried out using a full-scale 14 specimen. To prevent local buckling, the point load was applied at 1/4 points. After the experiment, theoretical analysis was conducted and the differences between various codes were identified. The experimental results were compared with AISI (the American Iron and Steel Institute), EC (Euro Code) 3, and KS (Korea Standard) codes. Analysis results are summarized as follows: (1) the failure mode was influenced by local buckling at the midpoint of the beam and/or at the intermediate loading point: (2) if yielding first occurred at the tension side, the moment strength would increase as the plastic reservation of the tension zone acted: (3) the experimental results were closest to the EC3 codes in which the partial plastic reservation was considered; (4) statistical evaluation based on the EC3 Annex Z showed that the partial resistance safety coefficient calculated applying to the EC3 formula, $^{\circ}{_M}$, was placed within 1.1 which was the target value of EC3 code; and (5) the analytical power of AISI and KS codeswere expected to improve into the level of EC3 codes if the concept of plastic reservation of the tension side would be introduced to them.

• Journal of Korean Society of Steel Construction
• /
• v.15 no.4 s.65
• /
• pp.359-368
• /
• 2003

Design and detailing requirements of seismic provisions for Concentrically Braced Frames (CBF) were specified based on the premise that bracing members with large KL/r and low b/t have superior seismic performance. However, relatively few tests have been done to investigate the cyclic behavior of CBF. Therefore, the question lies on whether the compression member of CBF plays as significant a role as what has been typically assumed by design providers. In this paper, existing experimental data were reviewed to quantify the extent of hysteretic energy achieved by bracing members in past compression tests as well as the extent of degradation of the compression force given repeated cycling loading.

• Journal of Korean Society of Steel Construction
• /
• v.15 no.5 s.66
• /
• pp.541-549
• /
• 2003

Split-tee connection with High Strength Bolts is normally used in low and middle rise buildings in Europe because the structural efficiency and installation work of connections are excellent. However, the domestic situation is different from that in Europe. The analysis and the design for the T-split connection are complicated, because the structural behavior often T-split connection with High Strength Bolt is governed by so many parameters, i.e., prying action, bolt's tension, shear failure and plastic failure of flange plates. Many researches regarding the structural behavior of the split-tee connection have been undertaken in other parts of the world, such as the, Americas, Japan and Europe, but in the domestic context, this is a pioneering study. Therefore, the purpose of this paper is to supply basic data for the design of T-split connection, and to verify the structural characteristics that define reactions to prying action, based on an experimental study.

• Journal of Korean Society of Steel Construction
• /
• v.16 no.5 s.72
• /
• pp.599-607
• /
• 2004

As buildings become more high-rise and lightweight in recent years, steel has been utilized more frequently. Based on the American AISC standard, all axial loads could be carried through a bearing load in a column splice, but according to Korean codes, the bearing load has constrained the stress that could be carried by only 25% of all axial loads. Thus, new column splice methods that use metal touch have been examined. In this study, the stress path mechanism, as an intermediation parameter in the gap's magnitude, must be determined. Similarly, the behavioral aspect of the metal touch connection must be sought after comparing and analyzing the results of the test.

• International Commerce and Information Review
• /
• v.2 no.1
• /
• pp.129-148
• /
• 2000

지적재산권은 기술개발의욕 자극을 위해 새로이 물건이나 사상 등의 창작자에게 일종의 배타적 독점권을 부여한 것으로서 1980년대 이후 국제적 관심이 고조되기 시작하였는데, 두 차례의 석유파동 이후 기술이 국제 경쟁력의 주요 결정요인으로 등장하던 시기에 한국을 비롯한 개도국들이 선진국의 기술을 모방하여 첨단기술제품 분야에서 경쟁적 우위를 확보하자 자신들의 경쟁력 확보를 위해 선진국들이 자신들의 통상교섭력을 바탕으로 GATT/UR 등 국제적 협상을 통해 지적재산권 보호문제를 통상문제로 확대시킨 것이다. 이러한 지적재산권에 대한 통상문제와 관련하여 가장 문제가 되는 국가는 역시 미국인데, 미국은 통상법 301조 중 지적재산권 보호에 적용되는 Special 301조를 이용하여 지적재산권 보호에 대한 실효성을 확보하였으며, 당초 제품수입상의 불공정거래행위에 적용하던 관세법 337조를 지적재산권을 침해하는 수입 판매행위에도 적용할 수 있도록 개정함으로써 그 보호수단을 더욱 강화하였는데, 이에 따라 우리도 적절한 대응방안의 모색이 요구되고 있다. 우선 정부의 입장에서는 대내적으로 원천기술 및 개량기술 개발을 통한 기술의 해외의존도 축소, 인센티브 도입 등 직무발명제도 활성화, 해외특허권 취득확대를 위한 중소기업의 해외출원비용 지원, 심사관의 전문화롤 통한 심사의 처리속도 및 질 향상, 특허기술정보 이용체제 개선을 위한 특허청의 정보전산화 및 산업기술정보원 톡허정보센타와의 유기적인 협조체제 구축, 기업의 특허분쟁대응능력 향상을 위한 전담부서 마련 및 국제특허분쟁 전문변리사 양성 등의 대안을 마련할 필요가 있으며, 대외적으로는 PLT협약 등 차후에 있을 국제협약에의 적극적인 참여를 통한 우리나라의 이익도모, 남북 가교역할의 강화 및 한 미 양국간의 법제적 차이에 대한 오해불식, 해당 산업에 영향을 줄 수 있는 로비 활동의 활성화 등의 대안이 필요하다. 또한 기업의 입장에서는 사전적으로 과감한 연구개발투자를 통한 산업재산권 확보, 기술 법률 언어능력을 고루 갖춘 특허전문가의 확보, 국제특허분쟁에 대한 대응체계 구축, 특허권 분쟁발생 방지를 위한 책임소재의 명확화 등의 근본적인 대책과 국제특허분쟁 차단을 위한 철저한 선행기술 조사, 해외기술의 개량 및 이용 촉진을 위한 크로스-라이센스의 활성화, 부실특허권에 대한 적극적인 무효심판청구, 제소정보에 대한 조기 입수, 설계변경이나 특허무효자료조사 등 침해회피 방법의 준비, 위험특허에 대한 철저한 예비조사 등의 부수적인 대책을 마련할 필요가 있으며, 일단 특허분쟁이 발생한 경우에는 당해 분쟁의 자사 생산 제품과의 관련여부 검토, 사건에 필요한 광범위한 정보 수집을 위한 전담팀 구성, 제소인의 특허권에 대한 면밀한 법률적 검토, 제소자에 대한 정확한 정보파악 및 최종 대응방안에 대한 신속한 결정, 자사의 특허를 이용한 제소자에 대한 역제소 등의 대응방안을 강구할 필요가 있는 것이다.

• Journal of Korean Society of Steel Construction
• /
• v.29 no.1
• /
• pp.81-88
• /
• 2017

Residual stress is defined as stress that already exists on a structural member from the effects of welding and plastic deformation before the application of loading. Due to such residual stress, welded H-section compression members under centroidal compression load can undergo buckling and failure for strength values smaller than the predicted buckling load and specified compressive strength. Therefore, this study was carried out to evaluate the effect of residual stress from welding on the determination of the buckling load and specified compressive strength of the H-section compression member according to the column length variation. A three-dimensional nonlinear finite element analysis was performed for the H-section compression member where the welded joint was fillet welded by applying heat inputs of 3.1kJ/mm and 3.6kJ/mm using the SAW welding method.

• Journal of Korean Society of Steel Construction
• /
• v.28 no.6
• /
• pp.439-448
• /
• 2016

Extended end-plate connections(EEPC) are a type of connection applied in Pre-Engineered Building structures comprising beam-column connections of steel structures or tapered members. Extended end-plate connections(EEPC) show different behavioral characteristics owing to the influence of plate thickness, gauge distance of high strength bolt, diameter of high strength bolt frame, and the number of high strength bolts. In the USA and Europe, extended end-plate connections(EEPC) are applied in beam-column connections of steel structures in various forms; however, these are not widely applied in structures in Korea.This can be attributed to the fact that the proposal of design strength types for extended end-plate connections(EEPC), proposal of connection specifications, evaluation of seismic performance, and are not being performed appropriately. Therefore, the purpose of this study is to provide basic data for the domestic application of Unstiffened extended endplate connections. To realize this, nonlinear finite element analysis was conducted on a 12-mm thick Unstiffened extended endplate connections.