• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.33-36
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• 2009

현행 도로교설계기준의 바닥판에 대한 설계방법은 휨 이론에 따라 바닥판을 단위 폭의 보로 보고 강도설계법으로 설계하고 있다. 그러나 실제 교량 바닥판의 파괴 형태는 펀칭에 의한 파괴이므로 바닥판의 극한성능은 펀칭전단강도를 토대로 평가해야 할 것이다. 하지만 기존에 연구된 결과로는 초간편 강합성 바닥판의 펀칭전단강도를 산정하기 어려워 이에 대한 연구가 필요한 실정이다. 본 연구에서는 개발된 초간편 강합성 바닥판의 펀칭전단성능을 파악하기 위하여 초간편 강합성 바닥판과 RC바닥판에 대한 펀칭전단실험을 실시하여 비교하여 보았다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2006.05a
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• pp.288-291
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• 2006

Piercing or blanking process is widely used to manufacture most of lead frame parts, but it is difficult to analyze the real process by the actual shape through progressive dies. In this paper several stages in progressive punching are modeled by 2D and 3D configurations using $DEFORM^{TM}$ 2D/ 3D code. During the progressive stage some state variables and deformed configurations are analyzed in each model. There are three stages in the process, the deformations at each stage are cumulative. The advantages and disadvantages of these two type modeling are discussed and analyzed. The experiments are performed as a working material copper alloy through manufactured die. Computed results in load by two types are compared to experiments.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.6
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• pp.115-122
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• 2012

The purpose of this study is to optimize the design of the jack-up platform for 5MW offshore wind turbine system. Considering all the environmental loads such as currents, waves, winds and so on, the members of structures have been designed and optimized based on the AISC and API-RP-2A to be within the allowable stress even in the most critical and severe condition. In addition to the above strength check of structural members, the joint punching shear check and the hydrostatic collapse check are also performed where they are required for the design. The design life of the jack-up platform is 50 years for the static strength check and the fatigue design life is 100 years including to the DFF(Design Fatigue Factor) of 2.0 to have enough stability and workability for the design optimization.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.383-388
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• 2005

In this paper Research development about a micro metal forming manufacturing system has been developed. A micro forming system has been achieved in Japan and it's developed micro press is limited to single forming process. To coincide with the purpose to be more practical, research and development is necessary about the press which the multi forming process is possible. We set the development of the equipment including micro deep drawing, micro punching and micro restriking process to the goal. To achieve this goal, Research about micro forming process to be related to multi process forming must be preceded first. Material selection and analysis about micro forming process are accomplished in this paper. And the basis research to make actual system is accomplished.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.39-40
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• 2011

The purpose of this study is to select a conductive resistor as high energy efficiency through analysis of the heating properties by induction heating. The result of this study, the heating properties is capable of weaken cementitious joint in 10~30 seconds when using the conductive resistor with wire mesh or punching metal. Although the steel is higher temperature than SUS304, SUS304's heating properties are more uniform.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05a
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• pp.3-4
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• 2011

The purpose of this study is to suggest basic data for development optimal disassembly manufacturing system during analysis pore structure and heating properties of cementitious joint using conductive resister by induction heating. From the results, we knew cementitious joint is weak easily by heating of conductive resister, such as wire mesh, punching metal, and steel fiber, from induction heating.

• International Journal of Automotive Technology
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• v.6 no.2
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• pp.191-196
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• 2005

A full-bead of multi-layer-steel (MLS) engine head gasket is used to seal the combustion gas. Finite element analyses were conducted to assess the dependence of the sealing performance of full-bead on the forming process consisting of embossing and flatting operations. It is demonstrated that the sealing performance is enhanced with more severe deformation of the bead plate during the embossing, i.e., with the increase in the punching depth, the punch height, the punch width and the friction coefficient of the bead plate against the punch and die, and with the decrease in the width of die cavity. Meanwhile, the flatting process that is employed to adjust the height of the embossed full-bead has no influence on the sealing performance.

• International Journal of Railway
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• v.2 no.4
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• pp.131-138
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• 2009

Static tensile and fatigue tests were conducted using tensile-shear specimens to evaluate the fatigue strength of a SPCC sheet clinch joint. The maximum tensile strength of the specimen produced at the optimal punching force was 1750 kN. The fatigue endurance limit (=760 N) approached 43% of the maximum tensile load (=1750 N) at a load ratio of 0.1, suggesting that the fatigue limit is approximately half of the value of the maximum tensile strength. The FEM analysis showed that at the fatigue endurance limit, the maximum von-Mises stress of 373 MPa is very close to the ultimate tensile strength of the SPCC sheet (=382 MPa).

• Computers and Concrete
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• v.27 no.4
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• pp.297-304
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• 2021

The hybrid Finite-Discrete Element (FDEM) approach combines aspects of both finite elements and discrete elements with fracture mechanics principles, and therefore it is well suited for realistic simulation of quasi-brittle materials. Notwithstanding, in the literature its application for the analysis of concrete is rather limited. In this paper, the proprietary FDEM code ELFEN is used to model concrete specimens under uniaxial compression and indirect tension (Brazilian tests) of different sizes. The results show that phenomena such as size effect and influence of strain-rate are captured using this modeling technique. In addition, a preliminary model of a slab subjected to dynamic shear punching due to progressive collapse is presented. The resulting fracturing pattern of the impacted slab is similar to observations from actual collapse.

• Journal of the Korean Geotechnical Society
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• v.16 no.1
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• pp.131-143
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• 2000

Several theoretical analyses are performed to predict the vertical load on embankment piles with cap beams. The piles are installed in a row in soft ground below the embankment and the cap beams are placed perpendicular to the longitudinal axis of the embankment. Two failure mechanisms such as the soil arching failure and the punching shear failure are investigated according to the failure pattern in embankment on soft ground supported by piles with cap beams. The soil arching can be developed when the space between cap beams is narrow and/or the embankment is high enough. In the investigation of the soil arching failure, the stability in the crown of the arch is compared with that above the cap beams. The factors affecting the load transfer in the embankment fill by soil arching are the space between cap beams, the width of cap beams and the soil parameters of the embankment fill. The portion of the embankment load carried by cap beams decreases with increment of the space between cap beams, while it increases with the embankment height, the width of cap beams, the internal friction angle and cohesion of the embankment fill. Thus, the factors affecting load transfer in embankment should be appropriately decided in order to maximize the effect of embankment load transfer by piles.