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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal Basic Information
Journal DOI :
The Korean Society for Composite Materials
Editor in Chief :
Volume & Issues
Volume 17, Issue 6 - Dec 2004
Volume 17, Issue 5 - Oct 2004
Volume 17, Issue 4 - Aug 2004
Volume 17, Issue 3 - Jun 2004
Volume 17, Issue 2 - Apr 2004
Volume 17, Issue 1 - Feb 2004
Selecting the target year
A Study on Tensile Properties of Multi-Welled Carbon Nanotube/Epoxy Composites
Lee Sang-Eui ; Lee Won-Jun ; Kim Chun-Gon ;
Composites Research, volume 17, issue 6, 2004, Pages 1~7
The studies of particulate reinforced composites have been conducted for many years. The nanocomposites to be studied vigorously in recent years are one of them. We fabricated and studied multi-walled carbon nanotube(MWNT)/epoxy composites which may be useful as matrix for continuous fiber-reinforced composites. We investigated tensile properties of MWNT/epoxy composites as a function of MWNT concentration, which were prepared by the fabrication method established in this study. Tensile stiffness and strength increased 19% at 0.5 wt% and 12% at 0.2 wt%, respectively. We observed the reaggregation phenomenon of MWNTS during curing, which should be controlled to obtain higher tensile properties.
Theoretical Investigation on the Stress-Strain Relationship for the Porous Shape Memory Alloy
Lee Jae-Kon ; Yum Young-Jin ; Choi Sung-Bae ;
Composites Research, volume 17, issue 6, 2004, Pages 8~13
A new three-dimensional model fur stress-strain relation of a porous shape memory alloy has been proposed, where Eshelby's equivalent inclusion method with Mori-Tanaka's mean field theory is used. The predicted stress-strain relations by the present model are compared and show good agreements with the experimental results for the Ni-Ti shape memory alloy with porosity of 12%. Unlike linear stress-strain relations during phase transformations by other models from the literature, the present model shows nonlinear stress-strain relation in the vicinity of martensite finish region.
Failure Mode and Strength of Unidirectional Composite Single Lap Bonded Joints I. Experiments
Kim Kwang-Soo ; Yoo Jae-Seok ; An Jae-Mo ; Jang Young-Soon ;
Composites Research, volume 17, issue 6, 2004, Pages 14~21
Failure process, mode and strength of unidirectional composite single lap bonded joints were investigated experimentally with respect to bonding methods, those are, co-curing with and without adhesive and secondary bonding. The co-cured joint specimens without adhesive had the largest failure strength. Progressive failures along the adhesive layer occurred in the secondary bonded specimens. In the co-cured specimens with adhesive film which had better material strength and adhesion performance, delamination failure occurred and the joint strengths were less than those of secondary bonded specimens. Delamination failure did not occur in the secondary bonded specimens because of earlier crack growth and progressive failure in the adhesive layer. Therefore, failure strength of composite bonded Joints were not always proportionate to material strength and adhesion performance of the adhesive due to the weakness of delamination in composite materials. The effects of surface roughness, bondline thickness and fillets were also studied on secondary bonded specimens.
Bending Fatigue Characteristics of Surface-Antenna-Structure
Kim D. H ; Hwang W ; Park H. C ; Park W. S ;
Composites Research, volume 17, issue 6, 2004, Pages 22~27
The objective of this work is to design Surface Antenna Structure (SAS) and investigate fatigue behavior of SAS that is asymmetric sandwich structure. This term, SAS, indicates that structural surface becomes antenna. Constituent materials are selected considering electrical properties, dielectric constant and tangent loss as well as mechanical properties. For the antenna performance, SSSFIP elements inserted into structural layers were designed fur satellite communication at a resonant frequency of 12.5 GHz and final demonstration article was
array antenna. From electrical measurements, it was shown that antenna performances were in good agreement with design requirements. In cyclic 4-point bending, flexure behavior was investigated by static and fatigue test. Fatigue life curve of SAS was obtained. The fatigue load was determined experimentally at a 0.75 (1.875kN) load level, Experimental results were compared with single load level fatigue life prediction equations (SFLPE) and in good agreement with SFLPE. SAS concept is the first serious attempt at integration fur both antenna and composite engineers and promises innovative future communication technology.
A Study on the Micro-deformation of Plain Weave Carbon/Epoxy Composite-Polymer Foam Sandwich Structures during Curing
Kim Yong-Soo ; Chang Seung-Hwan ;
Composites Research, volume 17, issue 6, 2004, Pages 28~36
Micro-tow deformation during forming of PVC foam-fabric composite sandwich structure is investigated to find out the correlation between forming condition and material deformation. The foams used in this research are PVC foams which have 4 different densities and the fabric composite is Carbon/epoxy prepreg which is plain weave (3k) as a skin material. Tow parameters such as crimp angle and tow amplitude are measured using microscope and a proper image tool and are compared with each other. In order to find out the effect of foam deformation during forming on tow deformation the compressive tests of foams are performed in three different environmental temperatures (
). The microscopic observation results show that the micro tow deformations are quite different from each other with respect to the foam density and forming pressure.
A Study of Relations of Chain Lengths and Properties for Bifunctional linear DGEBF/Linear Amino (EDA, HMDA) Cure Systems
Myung In-Ho ; Lee Jae-Rock ;
Composites Research, volume 17, issue 6, 2004, Pages 37~43
To determine the effect of chain length and chemical structure of linear amine curing agents on thermal and mechanical properties, a standard bifunctional linear DGEBF epoxy resin was cured with EDA and HMDA having amine group at the both ends of main chain in a stoichiometrically equivalent ratio in condition of preliminary and post cure. From this work, the effect of linear amine curing agents on the thermal and mechanical properties is significantly influenced by numbers of carbon atoms of main chain. In contrast, the results show that the DCEBF/EDA system having two carbons had higher values in the thermal stability, density, shrinkage (%), grass transition temperature, tensile modulus and strength, flexural modulus and strength than the DGEBF/HMDA system having six carbons, whereas the DGEBF/EDA cure system had relatively low values in maximum ekothermic temperature, maximum conversion of epoxide, thermal expansion coefficient than the DGEBF/HDMA cure system. These findings indicate that the packing capability (rigid property) in the EDA structure affects the thermal and mechanical properties predominantly. It shows that flexural fracture properties have a close relation to flexural modulus and strength.
Property Changes due to Numbers of Nitrogen Atom Bonded at Ethyl Group, Included in Main Chain of Curing Agents of DGEBGF/Linear Amino Systems
Myung In-Ho ; Lee Jae-Rock ;
Composites Research, volume 17, issue 6, 2004, Pages 44~51
To determine the effect of numbers of nitrogen atom bonded at ethyl group included in main chain of linear amine curing agents of epoxy-cure systems on the thermal and mechanical properties, standard epoxy resin DGEBF was cured with DETA, TETA and TEPA in a stoichiometrically equivalent ratio. From this work, the effect of curing agents of the DGEBF/amine systems oil the thermal and mechanical properties was significantly influenced by numbers of nitrogen atom of curing agents. The results showed that heat of reaction increased, and maximum exothermic temperature decreased with the decrease of numbers of nitrogen atom. In case of cured systems, density and maximum conversion(%) had no relation to numbers of nitrogen atom, but flexural modulus and tensile modulus increased with the decrease of numbers of nitrogen atom in main chain. Thermal stability, shrinkage(%), Tg, tensile and flexural strength showed irregular tendency having nothing to do with numbers of nitrogem atom at a sight. This findings imply that the differences in the maximum conversion(%) about the chain length of curing agents affect the thermal and mechanical properties.
A Study on Tensile Properties of CFRP Composites under Cryogenic Environment
Kim Myung-Gon ; Kang Sang-Guk ; Kim Chun-Gon ; Kong Cheol-Won ;
Composites Research, volume 17, issue 6, 2004, Pages 52~57
In this study, mechanical tensile properties of carbon fiber reinforced polymeric (CFRP) composite cycled with thermo-mechanical loading under cryogenic temperature (CT) were measured using cryogenic environmental chamber. Thermo-mechanical tensile cyclic loading (up to 10 times) was applied to graphite/epoxy unidirectional laminate composites far room temperature (RT) to
, RT to
and RT to
. Results showed that tensile stiffness obviously increased as temperature decreased while the thermo-mechanical cycling has little influence on it. Tensile strength, however, decreased as temperature down to CT while the reduction of strength showed little after CT-cycling. For the analysis of the test results, coefficient of thermal expansion (CTE) of laminate composite specimen at both RT and CT were measured and the interface between fiber and matrix was observed using SEM images.
How Phenolic Composites were chosen - In Case of England (6)
Nomaguchi, Kanemasa ; Forsdyke, Ken L ;
Composites Research, volume 17, issue 6, 2004, Pages 58~66
As the first modem industrialized country in the world, so England UK was safetyfied from "SMOKE FIRE DANCER" at London Underground as the first country also. Indeed, the quick decision maker of Grate London Metropolitan must be serious, while the technology developing people also so eager in rebuilding safer composite system for public security accumulating basic data at their laboratories. Mr. Ken L. Forsdyke, one of co-authors of this paper, who was the project leader at BP Chemicals International Company at that time, is now telling you some key points adding to the stories he mentioned before in this series, "How Phenolic Composites were chosen". Now, with another article of the basic data, our tales of "In Case England" will be closed. May God save people from "Horror SMOKE FIRE".ople from "Horror SMOKE FIRE".IRE&".ot;.
복합재 철도차량 차체의 유지보수기법
Composites Research, volume 17, issue 6, 2004, Pages 67~70