• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1997년도 춘계학술대회논문집
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• pp.159-164
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• 1997

The optimal conditions were investigated in order to manufacture the light automotive body parts using the semi-solid forging process by the finite element nalysis. Considering about macro-segregation cause to difference of relative velocity between solid phase and liquid phase, solidificational phenomenon cause to heat transfer from die and export of the latent heat, so solid fraction updating algorithm can be proposed. The rigid thermo-viscoplastic finite element analysis was carried out according to die temperature with proposed algorithm, so availability of forming part were understood. The finite element program can be used to the analysis of semi solid forging process.

• Computers and Concrete
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• 제12권1호
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• pp.19-36
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• 2013

In the finite element analysis of reinforced concrete structures, discrete representation of the steel reinforcing bars is considered advantageous over smeared representation because of the more realistic modelling of their bond-slip behaviour. However, there is up to now limited research on how to simulate the dowel action of discrete reinforcing bars, which is an important component of shear transfer in cracked concrete structures. Herein, a numerical model for the dowel action of discrete reinforcing bars is developed. It features derivation of the dowel stiffness based on the beam-on-elastic-foundation theory and direct assemblage of the dowel stiffness matrix into the stiffness matrices of adjoining concrete elements. The dowel action model is incorporated in a nonlinear finite element program based on secant stiffness formulation and application to deep beams tested by others demonstrates that the incorporation of dowel action can improve the accuracy of the finite element analysis.

• Journal of Advanced Marine Engineering and Technology
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• 제28권8호
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• pp.1279-1285
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• 2004

This paper presents the characteristic simulation of PM-type magnetic circuit breaker with the 2D finite element magnetic field solution including non-linearity of the material and an eddy current. Change of dynamic characteristic of the actuator is quantified from the finite element analysis. The results obtained from a commercial finite element analysis software are compared with those calculated from the developed finite element analysis software. A new modified model to decrease the eddy current is proposed. The characteristics of the two models are compared.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회A
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• pp.390-395
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• 2008

This study is performed to understand three dimensional characteristics of weld residual stress for the surface weld on the stainless steel plate. AISI 304 plate with one path weld on the surface was used as a test specimen. Finite element analysis was done to analyze thermal transient and residual stress due to weld. The result of finite element analysis was validated by previous paper and measurement data. Among various techniques for residual stress measurement, instrumented ball indentation method was applied. The calculated residual stresses by finite element analysis showed good agreement with the measured results.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집A
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• pp.458-463
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• 2000

The mechanical structures generally have discontinuous parts such as the cracks, notches and holes owing to various reasons. In this paper, in order to analyze effectively these singularity problems using the finite element method, a mixed analysis method which an analytical solution and finite element solutions are simultaneously used is newly proposed. As the analytical solution is used in the singularity region and the finite element solutions are used in the remaining regions except this singular zone, this analysis method reasonably provides for the numerical solution of a singularity problem. Through various numerical examples, it is shown that the proposed analysis method is very convenient and gives comparatively accurate solution.

• 대한기계학회논문집A
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• 제32권11호
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• pp.1022-1027
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• 2008

TPE is used as alternative for rubber, the best example is the weather strip for automobile. The nonlinear material properties of weather strip were important to predict the behaviors of weather strip. Uniaxial tension and equi-biaxial tension tests were performed to achieve the nonlinear material constant and stress-strain curves. The nonlinear material constant of weather strip is evaluated by using the nonlinear finite element analysis. In this paper, the prediction for weather strip is analyzed by using commercial finite element program, ANSYS. The nonlinear finite element analysis of weather strip is executed to predict the behavior of weather strip for automobile.

• 소성∙가공
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• 제10권5호
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• pp.389-395
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• 2001

An inverse finite element approach is employed for more capability to design the optimum blank shape from the desired final shape with small amount of computation time and effort. For multi-stage deep-drawing processes with large aspect ratio, numerical analysis is extremely difficult to carry out due to its complexities and convergence problem. as well as tremendous computation time. In this paper, multi-stage finite element inverse analysis is applied to multi-stage rectangular cup drawing processes to calculate intermediate blank shapes and strain distributions in each stages. Deformation history of the previous stage is considered in the computation. Finite element patches are used to describe arbitrary intermediate sliding constraint surfaces.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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• pp.569-576
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• 2003

Fundamental issues in static finite element analysis of reinforced concrete panel subjected to biaxial tensile loads are discussed. This paper is trying to bring our attention to the appropriate use of concrete material models such as cracking criteria, tension stiffening model and the steel models which are basically used in the nonlinear finite element analysis of reinforced concrete panels. We mainly investigate the sensitivity of available material models and finite element technologies to the finite element analysis result using our recent reinforced concrete panel experiment result. Throughout this study, we found that the judicious use of the material models and finite element technologies with the sound understanding of structural characteristics can only guarantee the accurate prediction of panel behaviour.

• 전기학회논문지
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• 제61권8호
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• pp.1123-1129
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• 2012

This paper presents the fast steady state analysis using time-stepping finite element method for a high power three-phase transformer. The high power transformer spends huge computational cost of the time-stepping finite element method. It is because that the high power transformer requires a lot of time to reach steady state by its large inductance component. In order to reduce computational cost, in this paper, the adaptive time-step control algorithm combined with the embedded 2nd 4th singly diagonally implicit Runge-Kutta method and the analysis strategy using variation of the winding resistance are studied, and their numerical results are compared with those from the typical time-stepping finite element method.

• Journal of Advanced Marine Engineering and Technology
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• 제28권1호
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• pp.83-89
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• 2004

Flare nut is an important Part that used to joint a brake tube-end in automobiles. It was made of SWCH 10A by machining. But we studied to make it by metal forming. The main focus of this paper is to investigate an optimal forging processes for flare nut using the DEFORM$^{TM}$-3D. commercially available finite element code and tests. Actually an explicit finite element analysis of the flare nut forging processes has been carried out to predict an optimal shape of the flare nut and its results were reflected in the tests of the forging processes design for flare nut. The simulation results which had obtained from finite element analysis were contributed to the forging processes design for flare nut. An optimal shape of nave nut showed agreements with test results. Furthermore. this paper should contribute to a development of the forging process for a variety of parts.s.