• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.229-233
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• 2015

복합재는 높은 비강도와 비강성을 가지고 있어 자동차, 항공기 등 전반적인 산업분야에서 널리 사용되는 재료이다. 우주선의 노즐 부분과 같이 높은 온도뿐만 아니라 높은 압력이 작용하는 환경에서 사용하기 위한 재료로 복합재가 필요하다. 복합재의 물성치를 아는 것은 매우 중요한데 모재(matrix)와 강화섬유(fiber) 각각의 물성치를 수치적으로 대입해 얻는 결과는 실험값과의 오차가 커 예측하는데 있어 더 정확한 방법이 필요할 것이다. 본 연구에서는 유한요소법을 이용한 EDISON용 CASADsolver 프로그램을 활용해 분석하였다. Matrix와 fiber의 물성치를 대입해 복합재의 물성치를 구해 실험으로 측정된 물성치, 경험식으로 계산된 물성치와 비교를 하였다.

• Composites Research
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• v.17 no.5
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• pp.25-38
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• 2004

In this study, the stiffness of spatially reinforced composites (SRC) are predicted by using superposition of a rod and matrix stiffnesses in an arbitrary direction. To confirm the predicted values, the material properties of SRC are measured. The predicted values from the volume average of stiffness matrix are consistent with the tested values in a rod direction, but are inconsistent in an off-rod direction while reverse is true fur the volume average of compliance matrix. Therefore, the harmony function from superposition of stiffness and compliance matrix is introduced. The predicted values from the harmony function are consistent with the tested values in both the rod and the off-rod directions.

• Journal of the korean Society of Automotive Engineers
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• v.16 no.4
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• pp.32-36
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• 1994

본 연구에서는 제진재의 최적화를 수행하기 위한 선행 단계로써 제진재 모델링에 필요한 제진재 물성치 산출법과 모델링 기법을 확립하였다. 1. 제진재 물성치(Loss factor ; .eta., Young's Modulus; E) 산출이론. 2. 실험을 통한 제진재 물성치 산출. 3. 제진재 모델링 방법 및 실험과의 비교.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.1
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• pp.61-65
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• 2016

Composites are materials that are widely used in industries such as automobile and aircraft. The composite material is required as a material for using in a high temperature environment as well as acting as a high pressure environment like the nozzle part of the ship. It is important to know the properties of composites. Result values obtained substituting the properties of matrix and fiber numerically have an large error compared with experimental value. In this study we utilize CASADsolver EDISON program for using Finite Element Method. Properties by substituting the fiber and Matrix properties of the composite material properties were compared with those measured in the experiment and calculated by the empirical properties.

• Journal of the Korean Geosynthetics Society
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• v.21 no.3
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• pp.1-10
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• 2022

In this paper, the spatial randomness and probability characteristics of material properties are inversely estimated by using a set of the stochastic fields for the material properties of geotechnical structures. By using the probability distribution and probability characteristics of these estimated material properties, topology optimization is performed on structure shape, and the results are compared with the existing deterministic topology optimization results. A set of stochastic fields for material properties is generated, and the spatial randomness of material properties in each field is simulated. The probability distribution and probability characteristics of actual material properties are estimated using the partial values of material properties in each stochastic field. The probability characteristics of the estimated actual material properties are compared with those of the stochastic field set. Also, response variability of the ground structure having a modulus of elasticity with randomness is compared with response variability of the ground structure having a modulus of elasticity without randomness. Therefore, the quantified stochastic topology optimization result can be obtained with considering the spatial randomness of actual material properties.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.36 no.4
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• pp.259-264
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• 2023

In this study, we devised a parametric analysis workflow for efficiently analyzing the material properties of 3D woven materials. The parametric model uses wire spacing in the woven materials as a design parameter; we generated 2,500 numerical models with various combinations of these design parameters. Using MATLAB and ANSYS software, we obtained various material properties, such as bulk modulus, thermal conductivity, and fluid permeability of the woven materials, through a parametric batch analysis. We then used this large dataset of material properties to perform a regression analysis to validate the relationship between design variables and material properties, as well as the accuracy of numerical analysis. Furthermore, we constructed an artificial neural network capable of predicting the material properties of 3D woven materials on the basis of the obtained material database. The trained network can accurately estimate the material properties of the woven materials with arbitrary design parameters, without the need for numerical analyses.

• Journal of Energy Engineering
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• v.12 no.3
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• pp.184-189
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• 2003

A study of the property of Indolene-Methanol Plus High Alcolhols (MPHA) has been completed. The study invested the measurement of fuel properties. The fuel properties investigated are distillation characteristics, heating value, flash point, specific gravity and water tolerance. The alcohol concentration was varied from 0 to 100 percent by volume in clear Indolene. The measurement of fuel properties indicated that, in general, Indolene-MPHA blends have higher water tolerance, similar specific gravity, similar flash point and different distillation characteristics compared to Indolene-Methanol blends.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.111-116
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• 2006

통신용 지하 관로 자재로는 주로 100mm관(PVC관, FC관)과 50mm관(FC관)이 사용되고 있으며, 이들 관자재의 품질은 관로 시공 품질 뿐 아니라 케이블 포설을 위한 선로 구성에 큰 영향을 미치고 있어, 관자재의 품질 확보는 매우 중요하다고 할 수 있다. 관자재의 품질 성능을 나타내는 방법으로는 편평시험(5% 및 100% 변형하중)과 충격시험 결과를 많이 사용하고 있으나, 관로 시공 현장에서 이러한 성능 시험을 한다는 것은 현실적으로 불가능하여, 대부분의 현장에서는 관자재의 두께나 무게와 같은 물성치 측정으로 품질관리를 하고 있다. 이에 본 논문에서는 관자재의 물성치와 품질 성능간 상호 관계를 분석한 후, 상관성이 높은 항목들을 도출함으로써, 관종 별의 관자재의 물성치와 품질 성능간에는 상관성이 매우 높은 인자들이 있다는 것을 규명하였으며, 이를 통하여 관자재의 물성치 만으로도 품질 성능을 객관적으로 판단할 수 있는 근거를 제시하였다. 이를 이용하여 관로 시공 현장에서 관자재 품질관리와 시공 품질 향상에 활용할 수 있도록 하였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.2
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• pp.157-163
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• 2010

Solid oxide fuel cells (SOFCs) are commonly composed of ceramic compartments, and it is known that the physical properties of the ceramic materials can be changed according to the operating temperature. Thus, the physical properties of the ceramic materials have to be properly predicted to develop a highly reliable simulation model. In this study, several physical properties that can affect the performance of SOFCs were selected, and simulation models for those physical properties were developed using our own code. The Gibbs free energy for the open circuit voltage, exchange current densities for the activation polarization, and electrical conductivity for the electrolyte were calculated. In addition, the diffusion coefficient-including the binary and Knudsen diffusion mechanisms-was calculated for mass transport analysis at the porous electrode. The physical property and electrochemical reaction models were then simulated simultaneously. The numerical results were compared with the experimental results and previous works studied by Chan et al. for code validation.

• Composites Research
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• v.33 no.2
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• pp.81-89
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• 2020

In this review paper, we introduce recent research studied effective physical properties of the reinforced composite using mean-field homogenization. We address homogenization for effective stiffness and expand it to effective thermal/electrical conductivity and dielectric constant. Multiphysics problems like piezoelectricity and thermoelectricity are considered by simplifying the constitutive equation into the linear equations like Hooke's law. We present a generalized theoretical formula for predicting effective physical properties of composite and validation by against finite element analysis.