• Journal of Power System Engineering
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• v.16 no.1
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• pp.78-83
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• 2012

The authors suggest the algorithm for the static analysis of a three dimensional solid structure by using the finite element-transfer stiffness coefficient method (FE-TSCM) and the hexahedral element of the finite element method (FEM). MATLAB codes were made by both FE-TSCM and FEM for the static analysis of three dimensional solid structure. They were applied to the static analyses of a very thick plate structure and a three dimensional solid structure. In this paper, as we compare the results of FE-TSCM with those of FEM, we confirm that FE-TSCM introducing the hexahedral element for the static analysis of a three dimensional solid structure is very effective from the viewpoint of the computational accuracy, speed, and storage.

• Journal of Industrial Technology
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• v.24 no.A
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• pp.23-28
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• 2004

Seat is one of the most important part of an automobile for passenger's safety especially when an accident happens. A recliner is a part of the seat assembly, having the function of adjusting the back-plate angle of a seat. Recently, many kinds of vehicles have adopted the round recliner module rather than the conventional types of recliners because of its broad compatibility and structural simplicity. In this study a two-dimensional finite element strength analysis has been performed using a commercial code ABAQUS/Standard for the purpose of developing a new round recliner model. The loading condition for the analysis is the same as the FMVSS 301 regulation. The finite element result for the round recliner has been compared with that for the conventional type.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.8 no.2
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• pp.215-225
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• 1988

The curved structures in space, such as multi-level interchanges, ramped structures, and circular curved structures can be modelled as helically curved members with constant helix angle. This paper presents a finite element approach for the analysis of the static and the free vibration characteristics of the helically curved members by using the 7th order Hermite interpolation functions. This method is used to find more accurate solution of the static and dynamic responses of them than those of the previous studies.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.12
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• pp.3007-3019
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• 1993

For the same configuration, the stiffness of 6-node two dimensional isoparametric is stiffer than that of 8-node two dimensional isoparametric element. This phenomenon may be called 'Relative Stiffness Stiffening Phenomenon.' In this paper, the relative stiffness stiffening phenomenon was studied, and could be corrected by modifying the position of Gauss integral points used in the numerical integration of the stiffness matrix. For the same deformation (bending) energy of 6-node and 8-node two dimensional isoparametric elements, Gauss integral points of 6-node element have to move closer, in comparison with those of 8-node element, in the case of numerical integration along the thickness direction.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.12 no.3
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• pp.465-474
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• 1999

A recently developed numerical method based on a volume integral formulation is applied to calculate the accurate stress intensity factors at the crack tips in unbounded isotropic solids in the presence of multiple anisotropic inclusions and cracks subject to external loads. In this paper, a detailed analysis of the stress intensity factors are carried out for an unbounded isotropic matrix containing an orthotropic cylindrical inclusion and a crack. The accuracy and effectiveness of the new method are examined through comparison with results obtained from analytical method and finite element method using ANSYS. It is demonstrated that this new method is very accurate and effective for solving plane elastostatic problems in unbounded solids containing anisotropic inclusions and cracks.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.5
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• pp.499-508
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• 2004

An efficient method of moments(MoM), which can lead to the analytical evaluation of the matrix elements, is proposed to analyze microstrip structures. The present method is formulated in conjunction with use of a new closed-form spatial-domain Green's functions which are derived by use of the integral formula for semi-infinite integrals of Bessel functions. It is observed that the computational efficiency such as the amount of calculation and computation speed has been improved due to the present MoM scheme by a factor of about 4 in comparison with the previous method. To validate the proposed method, several numerical examples are presented.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.1
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• pp.50-55
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• 2011

In this study, simultaneous aero-structural design was performed for HALE aircraft wing. The span and the shape of main spar were considered as design variables. To maximize aerodynamic performance and to minimize weight, multi-objective optimization was used. Nonlinear static aeroelastic analysis was performed to compute large deflection of wing. Design of experiment and response surface method were used to reduce computation cost in the design process. Also, aerodynamic performances of deformed wing and rigid wing were compared.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.3
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• pp.273-278
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• 2016

This study makes a relative comparison of the results of tensile test and quasi-static analysis using AGL(Adjuster Guide Loop) model that plays a role in adjusting the height of shoulder belt, of the components of the vehicle seatbelt system and attempts to propose a method of reducing the error rate of the quasi-static analysis technique effectively. This study selects two major factors affecting the result of an analysis, draws the result of analysis through the method of experimental design, one of the statistical techniques and understands the contribution rate of the major factors affecting the result of the analysis through ANOVA(Analysis of Variance).

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.2
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• pp.329-339
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• 2002

This research presents a systematic design procedure for supplemental viscoelastic dampers required to satisfy the given performance objectives using capacity spectrum method. To obtain required damper size, the amount of supplemental damping was computed from effective damping minus equivalent damping and inherent damping of structure. In the case of viscoelastic damper, iterative procedure is required because of the inherent stiffness of the damper. To verify the design method proposed in this study, parametric studies were performed for single degree of freedom systems with design variables. The method was also applied to a 10-story steel framed structure and the earthquake responses were obtained. According to time history analysis result the controlled displacements turned out to be close to the target displacement regardless of the design parameters.

• Journal of the Korean Geotechnical Society
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• v.17 no.5
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• pp.197-207
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• 2001

1980년대 이래 국내 터널의 시공법은 원지반의 강성을 활용한 NATM이 주를 이루고 있다. 그러나 NATM은 터널내부에 설치되는 내부라이닝의 여러 가지 문제점을 내포하고 있기 때문에 노르웨이에서는 조립식 터널 라이닝(Pre-Cast Concrete Lining, PCL)을 개발하여 현장타설 콘크리트 라이닝의 문제점을 해결하고자 하였다. 그러나 노르웨이와 같은 북유럽지역에서는 지진이 거의 발생되지 않고 있기 때문에 PCL공법 개발당시에 지진에 대한 영향을 고려하지 못하였다. 따라서 PCL공법을 국내에 도입하기 위해서는 먼저 지진에 대한 영향을 분석하여야 할 것으로 판단되므로 본 연구에서는 PCL공법 적용시 지진에 대한 안정성 평가 및 합리적 내진해석을 위한 연구를 수행하고자 하였다. PCL의 내진성능을 판단하기 위하여 먼저 국내에서 주로 많이 사용되고 있는 해석기법인 유사정적해석법과 응답스펙트럼해석법을 이용하여 분석하였으며 지반과 구조물의 상호작용에 대한 영향을 분석하기 위해 시간이력해석을 수행하여 터널심도별 PCL의 내진성능을 분석하였다. 이와 같은 방법으로 PCL의 내진해석을 수행한 결과, 부재에 발생된 응력이 허용응력 이내에서 발생되어 PCL의 내진성능을 확보된 것으로 판단된다. 또한 시간이력해석에 의한 지반-구조물 해석을 수행한 결과에 의하면 PCL의 내진성능을 확보하기 위한 터널의 최소 토피고가 터널직경에 2배 이상인 것으로 확인되었다. 또한 단순 구조물의 내진해석만으로는 PCL의 내진성능을 과소평가할 우려가 있는 것으로 나타났다.