• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.33-38
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• 2002

Nowdays, related with vehicle weight reduction, many automotive maker are trying to develop spaceframe. If aluminum member and steel member are applied together in constructing spaceframe, there will be many advantages in aspect of inclosing strength and saving weight of automotive. In this case, joining method of aluminum and steel members has to be proposed. For this method, electomagnetic joining has many advantages compared to welding. In this paper, joining of aluminum tube and steel tube using eletomagnetic pressure was studied and strength of joint was evaluated through commission test.

• International Journal of Automotive Technology
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• v.6 no.5
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• pp.519-527
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• 2005

Recently, weight reduction of vehicles has been of great interest and consequently the use of low-density materials in the automotive industry is increasing every year. However, the substitution of one material for another is not simple because it accompanies several problems, for example, weakness in the strength and stiffness and difficulty in the joining. To overcome these problems, the structure of the automobile redesigned totoally. Aluminum spaceframe is rapidly being adopted as a body structure for accommodating lightness, stiffness and strength requirement. In aluminum spaceframe manufacturing, it is often required to join aluminum tube. However, there are few suitable methods for joining aluminum tube, so that much interest has been focused on testing suitable joining methods. Joining by electromagnetic forming (EMF) can be useful method in joining aluminum tube, which offers some advantages compared with the conventional joining methods. In this paper, joining by EMF was investigated as a pre-study for applying an automotive spaceframe. Finite element simulations and strength tests were performed to analyze the influence of geometric parameters on joint strength. Based on these results, configurations of axial joint and torque joint were suggested and guidelines for designing EMF joint were established.

• Journal of Korean Society of Steel Construction
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• v.12 no.5 s.48
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• pp.475-485
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• 2000

In this study, an automated optimum design program for steel box girder bridges has been developed for the optimum design of composite steel box girder bridges. The design constraints required for the optimum design of steel box girder bridges are based on the Korean standard bridge specification. Considering characteristics of steel box girder bridges, several approximation techniques, such as artificial constraint deletion, variable linking and stress reanalysis technique etc. are also introduced to enhance the efficiency of optimization. The developed program is mainly composed of major sub-system modules including structural analysis module using commercial structural analysis program such as RM-SPACEFRAME, optimum design module, pre-process module for friendly user input, and post-processor module for office automation. In addition, in order to demonstrate the efficiency and applicability of the developed optimum design program for steel box girder bridges, a few numerical examples are applied. Based on the results of the application, it may be stated that the automatic optimum design program developed in this study can be a prototype model for the developement of optimum design program for other type of bridge.

• Journal of Korean Association for Spatial Structures
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• v.2 no.3 s.5
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• pp.81-92
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• 2002

The objective of this paper is to help to make decision of the appropriate structural types in long span structured building due to range of span. For the intention, based on 7 forces of structural element, it is analized the relationships among 6 configurations of structural element(d/1), 25 structural types, 4 materials, and span-length known with 186 sample from 1850 to 1996. 1) bending forces: $club(1/100{\sim}1/10),\;plate(1/100{\sim}1/10),\;rahmen(steel,\;10{\sim}24m)\;simple\;beam(PC,\;10{\sim}35m)$ 2) shearing forces: $shell(1/100{\sim}1/1000)\;hyperbolic\;paraboloids(RC,25{\sim}97m)$ 3) shearing+bending forces: plate, folded $plate(RC21{\sim}59m)$ 4) compression axial forces: club, $arch(RC,\;32{\sim}65m)$ 5) compression+tension forces: shell, braced dome $shell(RC,\;40{\sim}201m),\;vault\;shell(RC,\;16{\sim}103m)$ 6) compression+tension axial forces: $rod(1/1000{\sim}1/100)$, cable(below 1/1000)+rod, coble+rod+membrane(below 1/1000), planar $truss(steel,\;31{\sim}134m),\;arch\;truss(31{\sim}135m),\;horizontal\;spaceframe(29{\sim}10\;8m),\;portal\;frame(39{\sim}55m),\;domical\;space\;truss(44{\sim}222m),\;framed\;\;membrane(45{\sim}110m),\;hybrid\;\;membrane\;(42{\sim}256m)$ 7) tension forces: cable, membrane, $suspension(60{\sim}150m),\;cable\;\;beam(40{\sim}130m),\;tensile\;membrane(42{\sim}136m),\;cable\;-slayed(25{\sim}90m),\;suspension\;membrane(24{\sim}97m),\;single\;layer\;pneumatic\;structure(45{\sim}231m),\;double\;layer\;pneumatic\;structures(30{\sim}44m)$