• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.38 no.8
• /
• pp.798-805
• /
• 2010

Whole composite structure small class (150kg) satellite, STSAT-3, was initially developed in Korea. The structure does have aluminum frames that support the structure, and it is composed of only composite sandwich panels. A number of electronic boxes and mechanical apparatus will be shielded within the compartments built up by the composite panels. This study focused on the random vibration responses of the satellite. For this objective, vibration tests and analyses have been successfully performed with respect to STM (structure and thermal model) of the satellite. Additionally, through the experiment and theoretical analyses, the both results' accuracy was verified by comparison each other.

• Composites Research
• /
• v.33 no.5
• /
• pp.288-295
• /
• 2020

Fiber-reinforced composite laminates have high specific stiffness and strength and are expected to be useful for weight reduction in weight-sensitive industries, such as automotive and aerospace. However, designing composite laminates is often dependent on designer's experience and intuition because of difficulties in determining the number of plies and stacking sequence, which tends to lead to over-design. In this study, optimal design of composite laminates was performed to minimize weight, while withstanding the given load. Based on the enumeration method, all combinations of stacking sequence satisfying the design guideline for composite laminates were considered. Composite laminates were discretized into panels. Optimal number of plies and stacking sequence for each panel were determined considering local load on each panel and contiguity across adjacent panels. Failure index from Tsai-Wu criteria was optimized for strength and buckling analysis was performed for compressive load. Stacking angles of 0, ±45 and 90° were used.

• Fire Science and Engineering
• /
• v.26 no.6
• /
• pp.92-98
• /
• 2012

In this sturdy, large experimental (ISO 13785-2) was performed to analyze the building materials used in fire retardant materials for aluminum composite panel and in general properties. As a results, maximum temperature in the case of the general materials was measured in 210 seconds $1,021^{\circ}C$, the retardant materials was measured in 1,200 seconds early $1,190^{\circ}C$. The retardant material of aluminum composite panel, Fire behavior if the ignition is slow and the general materials in aluminum composite panel, fire ignition and combustion at the same time was growing rapidly. The general materials and flame-retardant material of aluminum composite panel was an obvious difference to the combustion ignition but after ignition combustion mode showed a similar pattern of the rapidly vertical spread of flame. The results of this study, in order to reduce the risk of aluminum composite panels for fire and the retardant materials used for ignition the slow should be actively encouraging. Also after the ignition, there is an urgent need to put out a fire in exterior materials for extinguishing facilities.

• Composites Research
• /
• v.28 no.2
• /
• pp.58-64
• /
• 2015

The purpose of this paper is to suggest the effective equivalent finite element model for the impact limiter of a nuclear spent fuel shipping cask made of sandwich composite panels. The sandwich composite panels were composed of a metallic facesheet and a core material made of urethane foam, balsa wood and red wood, respectively. The effective equivalent finite element model for the impact limiter was proposed by comparing the results of low-velocity impact test of sandwich panels. An explicit finite element analysis based on LS-DYNA 3D was done in this study. The results showed that the solid elements were recommended to model the facesheet and core of sandwich panels for impact limiter compared to combination modeling method, in which the layered shell element for facesheet and solid element for core material are used. In particular, the solid element for balsa and red wood core materials should be modeled by the element elimination approach.

• Fire Science and Engineering
• /
• v.24 no.2
• /
• pp.89-96
• /
• 2010

In this research, exterior material combustion experiment was really tested to evaluate fire risks of aluminium complex panel which is used a lot for building exterior material. As a result, We saw fast fire spreading of aluminium complex panel. The reason is polyethylene in aluminum complex panel combust spreading fast fire flame vertically. In this test, the highest heat release rate of aluminum complex panel was 1,144 kW and surface temperature which is measured by thermocouple went up to more than $903.3^{\circ}C$, that temperature is quite a higher than $660^{\circ}C$ which is aluminum melting temperature. So, fire of aluminum complex panel can be evaluated to give us severe damage both by fast fire spreading vertically and by fire spreading through openings internally. These results from real experiment will be able to use to predict fire spreading of aluminum complex panel by comparing to modeling materialization of aluminum complex panel in the future.

• Composites Research
• /
• v.20 no.4
• /
• pp.42-50
• /
• 2007

This paper describes the results of experiments and numerical simulation studies on the low-velocity impact damage of two different sandwich composite panels for application to bodyshell and floor structure of the BIMODAL tram vehicle. Square test samples of 100mm sides were subjected to low-velocity impact loading using an instrumented testing machine at four impact energy levels. Part of this work presented is focused on the finite element analysis of low-velocity impact response onto a sandwich composite panels. It is based on the application of explicit finite element (FE) analysis codes LS-DYNA 3D to study the impact response of sandwich structures under low-velocity impact conditions. Material testing was conducted to determine the input parameters for the metallic and composite material model, and the effective equivalent damage model for the orthotropic honeycomb materials. Numerical and experimental results showed a good agreement for damage area and the depth of indentation of sandwich composite panels created by the impact loading.

• 발명특허
• /
• v.31 no.7 s.361
• /
• pp.66-68
• /
• 2006

건축을 하는데 있어 무엇보다 중요한 것은 정확한 설계, 시공 및 뛰어난 기술력이며, 각 부분 부분마다의 정확성과 뛰어난 기술이 어우러져 튼튼하고 아름다운 집이 탕생하게 되는 것이다. 이런 조건은 충족시키는 첫 번째 요소라 할 수 있는 국내 건축용 외장재 시장은 약 1조원대의 시장을 형성하고 있으며, 전체 건축비의 약 10%정도를 차지한다. 건축용 외장재 시장은 석재, 유리, 알루미늄, 아연도금철판의 기본 소재에 다양한 가공을 통하여 제품을 생산하고 있으며, 가공 및 시공의 편의성으로 인해 금속계 패널이 점진적으로 시장을 주도하고 있다. 금속계 패널은 크게 복합판넬과 sheet 패널시장으로 양분되며, sheet패널시장이 약 20%정도의 시장을 차지하고 있다. 해외의 경우, 유럽과 일본은 알루미늄계열의 패널과 미국은 철판계열의 패널이 시장을 주도하고 있다.

• Composites Research
• /
• v.28 no.5
• /
• pp.291-296
• /
• 2015

In this study, structural design and analysis of the automobile bonnet is performed. The flax/vinly ester composite material is applied for structural design. The Vacuum Assisted Resin Transfer Molding-Light (VARTML) manufacturing method is adopted for manufacturing the flax fiber composite bonnet. The VARTML is a manufacturing process that the resin is injected into the fly layered-up fibers enclosed by a rigid mold tool under vacuum. A series of flax/vinyl ester composite panels are manufactured, and several kinds of specimens cut out from the panels are tested to obtain mechanical performance data. Based on this, structural design of the automobile bonnet is performed.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.12 no.4
• /
• pp.599-606
• /
• 1999

복합 적층 판과 보강 재를 설치한 보강된 복합 적층 패널의 좌굴을 고려한 설계에서, 좌굴이 항상 구조물의 최종 파손을 의미하는 것은 아니므로 이들의 좌굴 및 좌굴 후 거동에 대한 정확한 이해와 연구가 필요하다. 본 연구에서는 유한요소 법을 이용하여 적층 메커니즘과 섬유 배향각, 적층 순서 등이 복합 적층 판과 보강된 복합 적층 패널의 좌굴 및 좌굴 후 거동에 미치는 영향을 체계적으로 해석하였고, 각 변수에 따른 좌굴 및 좌굴 후 거동 특성을 분석하였다.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.23 no.5
• /
• pp.75-89
• /
• 2019

In the present work, structural analyses for light weight corrugate 3 layered sandwich panels are carried out. The mechanical properties of the sandwich panels are obtained using the modified analytical closed form based on a corrugated panel deformation and the homogenization scheme of an uniaxial composite. Subsequently, the mechanical properties estimated by the two aforementioned methods were employed for the numerical analyses for the corrugated sandwich panels under the specifically loading conditions, and a comparison between two methods was also made.