• Advanced Composite Materials
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• 제17권2호
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• pp.177-190
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• 2008

As the first step in discussing the reliability of composite structures, a fundamental study was performed to obtain the scattering characteristics of glass-fiber reinforced plastics (GFRP) and woven carbon fiber reinforced plastics (WCFRP) as well as a reference metal. The Euler buckling load was obtained experimentally for each material. The experiments were conducted for specified rectangular specimens with simply supported edges. A new attachment to realize the simply support boundary conditions for composite materials have been prepared before these experiments. The scattering data in the results for GFRP and WCFRP composites were compared with those of a typical metal of aluminum alloy. The experimental data were also compared with numerical simulations including the uncertainties.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2006년도 춘계학술대회 논문집
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• pp.259-260
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• 2006

The ESPI(Electronic Speckle Pattern Interferometry) is a real time, full-field, non-destructive optical measurement technique. In this study, ESPI is proposed for the purpose of vibration analysis for new material, composite material. Composite materials have various complicated characteristics according to the ply materials, ply orientations, ply stacking sequences and boundary conditions. Therefore, it is difficult to analysis composite materials. For efficient use of composite materials in engineering applications the dynamic behavior, that is, natural frequencies, nodal patterns should be informed. If use Time-Average ESPI, can analyze vibration characteristic of composite material by real time easily. This study manufactured laminated composite of symmetry, asymmetry two kinds that is consisted of CFRP(Carbon Fiber Reinforced Plastics) and shape of test piece is rectangular form.

• 한국기계가공학회지
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• 제21권2호
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• pp.137-143
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• 2022

Composite materials, being light-weight and of high mechanical strength, are increasingly used in various industries such as the aerospace, automobile, sporting-goods manufacturing, and ship-building industries. Recently, manufacturing of composite materials using 3D printers has increased. 3D-printed composite materials are made in free-form and adapted for end-use by adjusting the fiber content and orientation. However, research on the machining of 3D printed composite materials is limited. The aim of this study is to develop a machine learning method to select machining conditions for machining of 3D-printed composite materials. The composite material was composed of Onyx and carbon fibers and stacked sequentially. The experiments were performed using the following machining conditions: spindle speed, feed rate, depth of cut, and machining direction. Cutting forces of the different machining conditions were measured by milling the composite materials. PCA, a method of machine learning, was developed to select the machining conditions and will be used in subsequent experiments under various machining conditions.

• Restorative Dentistry and Endodontics
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• 제46권2호
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• pp.18.1-18.13
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• 2021

Composite resins are the most commonly used dental restorative materials after minimally invasive dental procedures, and they offer an aesthetically pleasing appearance. An ideal composite restorative material should have wear properties similar to those of tooth tissues. Wear refers to the damaging, gradual loss or deformation of a material at solid surfaces. Depending on the mechanism of action, wear can be categorized as abrasive, adhesive, fatigue, or corrosive. Currently used composite resins cover a wide range of materials with diverse properties, offering dental clinicians multiple choices for anterior and posterior teeth. In order to improve the mechanical properties and the resistance to wear of composite materials, many types of monomers, silane coupling agents, and reinforcing fillers have been developed. Since resistance to wear is an important factor in determining the clinical success of composite resins, the purpose of this literature review was to define what constitutes wear. The discussion focuses on factors that contribute to the extent of wear as well as to the prevention of wear. Finally, the behavior of various types of existing composite materials such as nanohybrid, flowable, and computer-assisted design/computer-assisted manufacturing materials, was investigated, along with the factors that may cause or contribute to their wear.

• Journal of the Korean Wood Science and Technology
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• 제25권4호
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• pp.29-38
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• 1997

The effect and control of wood property of reconstituted composite panels for improved board properties by wood-waste materials and development of combination method for heterogeneous materials have been of interest to the wood science researchers. The purpose of this study is to consider the properties in relation to hot pressing conditions and to develope the optimum hot pressing condition with waste wood and waste tire for the manufacturing of composite boards. The study of composite boards for recycling of wood and waste tire is nothing up to the present. Physical and mechanical properties such as specific gravity, moisture content, swelling coefficient, modulus of rupture and modulus of elasticity in bending test were studied. The condition of 3-stage press time for the lowest moisture content of composite board was $4{\rightarrow}3{\rightarrow}3$ minutes. Specific gravity of composite panels was affected mainly by the amount of rubber chip. Because of the low rigidity and high elasticity in rubber chip, it is considered the composite panel was adequate material in the place of compression load, but not bending load. Therefore, it was concluded that a use of rubber-based wood composite panel is proper to the interior materials such as floor a room than exterior materials. From the test results, the most optimum hot pressing conditions were $4{\rightarrow}3{\rightarrow}3$ minutes for 3-stage press time and $45{\rightarrow}20{\rightarrow}5kg/cm^2$ for 3-stage press pressure. The rubber-based wood composite panel was very excellent in elasticity by combination of rubber chip in comparison with existing other wood-based materials. Therefore, it was considered that rubber-based wood composites can be applicable to every interior materials such as floor a room and will be expected to effective reuse and recycle of waste tires and wood-waste materials, and will be contribute to protection of environment pollution in earth.

• Composites Research
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• 제33권5호
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• pp.251-255
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• 2020

본 연구에서는 용융가압함침공정을 이용하여 제조된 TiC 세라믹 입자강화 철강복합재를 제조하고 상용구상흑연주철과 비교를 위하여 미세조직 분석 및 경도 등 기초물성과 선박 해양 분야등의 적용가능성 검토를 위하여 염수환경에서의 부식 특성에 관한 연구를 진행하였다. 염수환경에서의 부식특성 비교 결과 구상흑연주철 대비 부식전위와 부식전류밀도 모두 낮은 값을 나타내었고, 낮은 연간부식률을 통하여 TiC-Fe 금속복합재의 내식성이 더 뛰어난 것을 확인하였다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2000년도 춘계학술발표대회 논문집
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• pp.26-30
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• 2000

• KSBB Journal
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• 제32권3호
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• pp.174-178
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• 2017

Fungal mycelium-based composite materials (FMBC) are a new biomaterial to replace the existing composite materials. To compete with lightweight, high-performance composite materials represented by fiber-reinforced plastic (FRP), various physical and chemical properties and functionality must be secured. Especially, the composite materials made by using mycelium of mushroom is called mushroom plastic. Currently, Ecovative, Grado Zero Espace and MycoWorks in USA and Europe are launching new products. Products utilizing FMBC can be launched in the market for construction materials, automobile interior materials and artificial leather substitutes. In spite of this high possibility, mass production using FMBC has not yet been reported. This review introduces the FMBC, a material that can replace existing plastics, inorganic building materials and animal skins in an environmentally and economically viable way, and looks at the possibility of future biomaterials by summarizing recent research contents.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.388-392
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• 1995

The Electronic Speckle Pattern Interferometry(ESPI) has been applied to many technical problems such as deformation and displacement measurement, strain visualization and surface roughness monitoring. Composite materials have various complicated characteristics depending on the ply materials,ply orientations,ply stacking sequences and boundary conditions. Therefore, it is difficult to analyze composite material. For efficient use of composit materials in engineering applications, the dynamic behavior such as, natural frequencies and modal patterns should be identified. This studying presents FEM results for the free vibration of symmetrically laminated composite as [30/-30/90] $_{s}$. The natural frequencies of laminated composite rectangular plates having the boundary condition(:2-edge clamped) are experimentally obtained. In order to demonstrate the validity of the experiment,FEM analysis using ANSYS was performed and natural frequencies experimentally obtained is compared with calculated by FEM analysis. The results obtained from both experiment and FEM analysis show a good agreement.t.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 추계학술발표대회 논문집
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• pp.207-211
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• 2004

There are the marked differences between the design techniques of carbody structures made of composite materials and metal materials. The design techniques of carbody structures made of metal materials have already been guaranteed in the domestic field. But, in case of the hybrid composite carbody structures, it is the first attempt to be developed and there is no experience of the design in the railway applications. In this paper, the design techniques of hybrid composite structures were introduced and compared with that of the conventional metal carbody.