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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal Basic Information
Journal DOI :
The Korean Society for Composite Materials
Editor in Chief :
Volume & Issues
Volume 22, Issue 6 - Dec 2009
Volume 22, Issue 5 - Oct 2009
Volume 22, Issue 4 - Aug 2009
Volume 22, Issue 3 - Jun 2009
Volume 22, Issue 2 - Apr 2009
Volume 22, Issue 1 - Feb 2009
Selecting the target year
Smart Structural Health Monitoring Using Carbon Nanotube Polymer Composites
Park, Young-Bin ; Pham, Giang T. ; Wang, Ben ; Kim, Sang-Woo ;
Composites Research, volume 22, issue 6, 2009, Pages 1~6
This paper presents an experimental study on the piezoresistive behavior of nanocomposite strain sensors subjected to various loading modes and their capability to detect structural deformations and damages. The electrically conductive nanocomposites were fabricated in the form of a film using various types of thermoplastic polymers and multi-walled carbon nanotubes (MWNTs) at various loadings. In this study, the nanocomposite strain sensors were bonded to a substrate and subjected to tension, flexure, or compression. In tension and flexure, the resistivity change showed dependence on measurement direction, indicating that the sensors can be used for multi-directional strain sensing. In addition, the sensors exhibited a decreasing behavior in resistivity as the compressive load was applied, suggesting that they can be used for pressure sensing. This study demonstrates that the nanocomposite strain sensors can provide a pathway to affordable, effective, and versatile structural health monitoring.
Fabrication of composite hinge mechanism for flapping-wing motion of micro air vehicle
Kang, Lae-Hyong ; Jang, Hee-Suk ; Leem, Ju-Young ; Han, Jae-Hung ;
Composites Research, volume 22, issue 6, 2009, Pages 7~12
This paper deals with a fabrication method of composite hinge mechanisms for flapping-wing micro air vehicles. The fabrication process includes curing process of Graphite/Epoxyprepregs, laser cutting for high fabrication repeatability, laminating of Graphite/Epoxy prepregs with Kapton film which is used for flexure, and so on. The fabricated hinge mechanism was attached with PUMPS actuators and the measured flapping angle was
when driving voltage was 300V 170Hz.
Manufacturing Technology and Evaluation for X-ray Transmission Performance of CT Cradle composed of Sandwich Composites
Lee, Sang-Jin ; Kim, Jong-Chul ; Kim, Min-Woo ; Park, Ja-Yeon ;
Composites Research, volume 22, issue 6, 2009, Pages 13~17
This paper decided the 3D shape of sandwich composite for the cradle of CT instrument, suggested the stacking sequence with satisfaction on structural criteria using the Finite Element Analysis, and introduced the manufacturing method to meet the X-ray transmission performance uniformly. The design of Cradle was considered the space between other parts, fixing method, and assembly condition with headrest part. It is decided the stacking sequence to meet the criteria that the deflection at the end point is less than 20 mm when it is applied to 135 kg load at the specific locations. In site of manufacturing method, at first, it is used the hand lay-up for carbon UD and carbon fabric/polyester resin, but it had the ununiform X-ray transmission performance due to the void and excess resin. For solving this problem, it was replaced with the infusion method for the first layer of face material and the application of carbon UD or fabric/epoxy resin prepreg for other layers. Therefor, the property of X-ray transmission was improved.
Probability Analysis for Impact Behavior of Composite Laminates Subjected to Low-Velocity Impact
Ha, Seung-Chul ; Kim, In-Gul ; Lee, Seok-Je ; Cho, Sang-Gyu ; Jang, Moon-Ho ; Choi, Ik-Hyeon ;
Composites Research, volume 22, issue 6, 2009, Pages 18~22
In this paper, we examined impact force and impact behavior through low velocity impact tests of composite laminates. And through c-scan as nondestructive inspection, explored the damaged area being difficult to examine with the visual inspection. Through CAI tests, we also measured the compression strength of composite laminates subjected to low velocity impact. To examine the characteristics of impact behavior measured from low velocity impact test, nondestructive inspection, and CAI test, the simulated data are generated from the test data using Monte-Carlo simulation, then represented it by probability distribution. The testing results using visible stochastic distribution were examined and compared.
Acoustic Emission Characteristics and Fracture Behaviors of GFRP-Aluminum Honeycomb Hybrid Laminates under Compressive and Bending Loads
Lee, Ki-Ho ; Gu, Ja-Uk ; Choi, Nak-Sam ;
Composites Research, volume 22, issue 6, 2009, Pages 23~31
This paper investigated acoustic emission (AE) characteristics in association with various fracture processes of glass fiber reinforced plastic skin/ aluminum honeycomb core (GF-AH) hybrid composites under compressive and bending loads. Various failure modes such as skin layer fracture, skin/core interfacial fracture, and local plastic yield buckling and cell wall adhesive fracture occurring in the honeycomb cell wall were classified through the fracture identification in association with the AE frequency and amplitude analysis. The distribution of the event-rate in which it has a high amplitude showed a procedure of cell wall adhesive fracture, skin/core interfacial debonding and fiber breakage, whereas distribution of different peak frequencies indicated the plastic deformation of aluminum cell wall and the friction between honeycomb walls. Consequently, the fracture behaviors of GF-AH hybrid composites could be characterized through a nondestructive evaluation employing the AE technique.
Effects of Reinforced Fibers on Energy Absorption Characteristics under Quasi-static Compressive Loading of Composite Circular Tubes
Kim, Jung-Seok ; Yoon, Huk-Jin ; Lee, Ho-Sun ; Choi, Kyung-Hoon ;
Composites Research, volume 22, issue 6, 2009, Pages 32~38
In this study, the energy absorption capabilities and failure modes of four different kinds of circular tubes made of carbon, Kevlar and carbon-Kevlar hybrid composites with epoxy resin have been evaluated. In order to achieve these goals, these tubes were fabricated with unidirectional prepregs and compressive tests were conducted for the tubes under 10mm/min loading speed. From the test results, carbon/epoxy tubes were collapsed by brittle fracturing mode and showed the best energy absorption capabilities, while Kevlar/epoxy tubes were crushed by local buckling mode and worst. The hybrid [
] tubes were failed in a local bucking mode and showed good post crushing integrity, whereas [
] tubes were failed in a lamina bending mode and bad post crushing integrity.
Aging Characteristics of Carbon Fiber/Epoxy Composite Ring Specimen
Yoon, Sung-Ho ; Oh, Jin-Oh ;
Composites Research, volume 22, issue 6, 2009, Pages 39~44
The effect of exposure times on the aging characteristics of carbon fiber/epoxy composite ring specimen was evaluated using an accelerating aging tester. Combined exposure conditions, such as temperature, moisture, and ultraviolet, were applied up to 3000 hours. Tensile properties and flexural properties including the effect of curvature were evaluated on the specimens subject to various exposure times through a material testing system. Their aging surfaces were observed through a scanning electron microscope. According to the results, tensile modulus was little affected by the exposure times. However, tensile strength, at the early stage of the exposure times, increased due to physical aging and curing reaction, but tensile strength slightly decreased due to degradation as the exposure times increased. The flexural modulus and flexural strength increased at the early stage of the exposure times, but slightly decreased as the exposure times increased. Aging surfaces of the specimens examined using the scanning electron microscope revealed a different morphology in various exposure times and provided useful information for identifying the degradation in mechanical properties of the composite subject to various exposure times.
Interfacial fracture analysis of human tooth/composite resin restoration using acoustic emission
Gu, Ja-Uk ; Choi, Nak-Sam ; Arakawa, Kazuo ;
Composites Research, volume 22, issue 6, 2009, Pages 45~51
The marginal integrity at the composite resin-tooth interface has been analyzed in real time through acoustic emission (AE) monitoring during the polymerization shrinkage of composite resin subjected to the light exposure. It was found that AE signals were generated by the polymerization shrinkage. Most AE hit events showed a blast type signal having the principal frequency band of 100-200kHz. Bad bonding states were indicated by many hit events in the initial curing period of 1 minute with high contraction rate. The quantity of hit events for the human molar dentin specimen was much less than that for the steel ring specimen but more than that for the PMMA ring specimen. The better the bonding state, the less the AE hit events. The AE characteristics were related with the tensile crack propagation occurring in the adhesive region between the composite resin and the ring substrate as well as the compressive behavior of the ring substrate, which could be used for a nondestructive characterization of the marginal disintegrative fracture of the dental restoration.
개인방호용 복합재료의 기술동향
Yuk, Jong-Il ; Yun, Byeong-Il ; Baek, Jong-Gyu ; Song, Heung-Seop ;
Composites Research, volume 22, issue 6, 2009, Pages 52~62
This paper is for the state of the art of the lightweight protective clothing against the mine, and it covers the preliminary work focused on the appropriate protection, ballistics, convenience, and wearability. It is suggested that the lightweight protective clothing should be fabricated with the laminated materials of high strength woven and non-woven fabrics to reduce the weight and thickness, thus improving the wearability. And partial reinforcement of the protective clothing is necessary to prevent the mortal wound near the important parts of the body without disturbing the arbitrary activity. The composition of the protective clothing should be designed in consideration of easy putting-on and taking-off in addition to easy divesture, which require little motion of the body is in case of serious injury. Additionally, status of the practical technique for high performance and ultra-light hybrid armor material were also described.