• Journal of the Korean Society for Advanced Composite Structures
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• v.2 no.3
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• pp.18-24
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• 2011

In this paper, we present the load-deflection behavior of GRP pipes. GRP buried pipes are widely used in construction in the advantage of their superior mechanical and physical characteristics such as high chemical resistance, high corrosion resistance, right weight, smooth surface of the pipe, and cost effectiveness from soil-structure interaction. To design flexible pipes to be buried underground, it should be based on the ASTM D2412(2010). When applying ASTM D 2412(2010) to the design, pipe stiffness(PS) must be predetermined by the parallel-plate test which requires tedious and laborious working process. To overcome such problems, the finite element simulations for finding the load-deflection behavior of the GRP flexible pipes is installed at UTM testing machine. In the finite element simulations, basic data, such as the modulus of elasticity of the material and cross-sectional dimension, is used. From the investigation, we found that the difference between experimental result and analytical prediction is less than 15% when the pipe deflected 3% and 5% of its vertical diameter although the pipe material is not uniform across the cross-section.

• Journal of Korean Library and Information Science Society
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• v.46 no.4
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• pp.139-159
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• 2015

With advancement of information technology and accumulation of digital resources, the demand on collaboration among libraries, museums and repositories are increasing. The purpose of this study is to propose Korean literature houses as an example of larchiveum. This study explored data management, exhibits and programs of Korean literature house.

• 한국방재학회:학술대회논문집
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• 2011.02a
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• pp.177-177
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• 2011

현재 대부분 사용되는 지하매설물용 뒤채움재는 다짐공법을 많이 사용하고 있으며, 실제로 이러한 방법은 부적절한 다짐으로 인해 침하 및 내구성 저하로 인해 파손을 초래하는 경우가 많다. 이러한 문제를 해결 할 수 있는 하나의 대안으로 유동성 뒤채움재를 이용할 수 있다. 유동성 뒤채움재는 초기 유동성, 시간에 따른 자기 강도 발현 무다짐공법 적용 등 많은 장점을 가지고 있다. 본 연구에서는 현장발생토사, 정수장슬러지 및 폐타이어분말 등 재활용 재료를 이용한 유동성 뒤채움재의 기본물성을 평가하였다. 각각의 재활용재료에 대한 입도 및 비중을 평가하였고, 최적배합설계를 결정하였으며, 모형 시험과 유한요소 해석을 위한 기본 물성값을 위해 일축압축시험, 삼축압축시험, 공진주시험 등을 수행하였다. 최적배합설계를 산정하는 과정에서 수행한 실험중 대표적인 시험으로 자가수평능력 및 자기다짐등에 필요한 유동성을 판단하는 Flow시험(ASTM D 6133) 결과 기준으로 정한 20cm이상의 값을 얻을 수 있었으며 일축압축강도의 경우 시공 후 유지 보수가 용이한 강도인 $3.0kg/cm^2{\sim}5.6kg/cm^2$이하로 설계하였으며 28일재령 일축압축강도 결과 $3.15{\sim}3.74kg/cm^2$라는 유지보수에 적당한 결과값을 나타내었다. 이 배합이 현장에서 사용이 가능하다는 것으로 판단하고 현장모형시험과 유한요소해석를 통하여 현장에서 사용하였을 때 관의 변형과 관에 작용하는 하중변화를 확인하고 현장모형시험과 유한요소해석 간의 상관관계를 규명하였다. 현장 모형 시험은 현장과 비슷하게 제작된 모형을 이용하였으며 최대한 현장과 비슷한 조건에서 뒤채움재를 타설과정 중과 타설이 완료된 상태에서 7일 양생 후 하중재하와 같이 두가지 경우에서 수직 수평토압, 관의 수직 수평변위, 관의 종단변형을 측정하였다. 유한요소해석 프로그램은 Midas GTS를 이용하여 실시하였으며 관의 변형률, 유효응력을 측정하여 규명하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.3
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• pp.271-276
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• 2024

Traditional oil, a depleting resource, accounts for only one-third of the world's oil reserves, so research and cases of utilizing non-traditional oil as a resource are continuously increasing. However, unconventional oil contains bitumen containing solid particles such as sand, and because it is exposed to a high temperature and high pressure environment, deformation can frequently occur in oil pipelines. Therefore, variables such as material, thickness, and angle that can affect the deformation of the oil pipeline were derived and applied to the oil pipeline, and finite element analysis was performed using the Ansys program. As a result of finite element analysis, deformation and maximum load capacity were derived. Afterwards, the same analysis was performed by modeling an optimized oil pipeline by combining the factors with the best deformation resistance and maximum load capacity. As a result of the analysis, the effect of reducing deformation and increasing the maximum load capacity by about 30 % was confirmed, and factors for suppressing deformation when analyzing oil pipelines were derived.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.5
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• pp.78-83
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• 2015

In the composite case, the first ply failure is considered total failure of the case. When the case is constructed by filament winding over a metal liner, the first ply failure does not necessarily mean total failure of the case. In this study, we compared the results through finite element analysis and burst test to predict the burst pressure of the hybrid case (filament-wound composite case with metal liner). Through it predicts the burst pressure of the hybrid case, we can determine the thickness of the metal liner and composite.

• Aerospace Engineering and Technology
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• v.11 no.1
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• pp.91-97
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• 2012

The structural analyses and experimental results for the bellows of a gas-generator liquid oxygen shut-off valve were presented. The bellows experiences axial compression and external high pressure loadings at cryogenic temperatures. The analyses were performed using EJMA (Expansion Joint Manufacturing Association) standard and the commercial FE (finite element) analysis program, Abaqus v6.9, at room and cryogenic temperatures. The spring modulus, the induced stress and the expected fatigue life of the bellows were compared respectively. The effects by the contact and the material plasticity on the FE analysis results were also analyzed. Also, FE analyses related to a burst test were presented.

• Journal of the Korea institute for structural maintenance and inspection
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• v.11 no.2
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• pp.77-84
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• 2007

The elastic buckling strength of a corrugated pipe made of orthotropic material was evaluated. The height and length of a corrugated wave and the thickness of the pipe were considered as factors affecting the buckling strength of the pipe. And also, the ratio of the longitudinal stiffness and transverse stiffness were considered as parameters affecting on the buckling strength of a pipe made of orthotropic material. Buckling strengths of various corrugated pipes with different shapes and stiffness ratio were evaluated by FE analyses. And a formula to estimate the elastic buckling strength was suggested by regression of FE analysis results. Analysis results show that a corrugated pipe has superior buckling strength to a general flat pipe and the suggested formula estimates accurate buckling strength of the corrugated pipe made of orthotropic material.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1994.10a
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• pp.306-311
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• 1994

본 연구에서는 축대칭 형태의 음향문제를 해석할 수 있는 경계요소 프로그램을 개발하여 소음기의 투과손실(transmission loss)의 계산에 적용하였다. 우선 단순팽창관 소음기에 대해서는 경계요소법에 의해 투과손실을 구한 후 평면파이론 및 실험으로 구한 값과 비교 평가하였다. 또한, 평면파이론을 적용할 수 없는 경우로서 흡음재를 부착한 팽창관 소음기에 대해서는 경계요소법으로 구한 투과손실을 실험결과와 비교 고찰하였다.

• Journal of the Korean Society for Nondestructive Testing
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• v.20 no.3
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• pp.191-199
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• 2000

In this paper, a numerical analysis using the finite element method (FEM) is presented which models the eddy current testing (ECT) of tubes with 3-dimensional defects. For the description of 3-dimensional eddy current problems, the governing equation is derived from the Maxwell's equations. The 3-dimensional FEM formulation with hexahedral elements is carried out using the Galerkin weighted residual method. The INCONEL 600 steam generator tube with inner and outer diameter defects is adopted for the numerical analysis, and the ECT signal, which is the trajectory of the probe impedance, is calculated. For the verification of the numerical analysis method, results of numerical calculations and experiments are compared and they show good agreements. Based on this verification, several defect signals are predicted and their characteristics are investigated with the variation in the defect depth and the circumferential angle of the defect.

• Archives of design research
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• v.21
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• pp.161-170
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• 1997

The study as explained above has been progressed as follows: Through the theoretical required for projecting the corporate's exhibition at exposition, the justifiability of this study was recognized. To approach the pavilion of exhibition the importance of marketing communication at the corporate and its forming process were suggested, and the public information of the corporate as a medium of its marketing communication was under-stood. - With regard to the exhibiting event as its method, general constituents and contents of it were closely looked into, and on the exposition, as a kind of corporate's event and a place for the reciprocally exchangeable communication between the corporate and the public, a general study was done. - The importance of identification of the corporate's image for the corporate to participate in an exposition and its analytic method were refined in the stages of 'basic image' and 'serve image', and the general process in which the corporate is processing the image of its own pusiness since its participation in exposition was suggested in terms a model, dividing it into the stages of inspection & analysis and design.