• 제목/요약/키워드: Composite Material

검색결과 5,075건 처리시간 0.036초

Cost optimization of composite floor trusses

  • Klansek, Uros;Silih, Simon;Kravanja, Stojan
    • Steel and Composite Structures
    • /
    • 제6권5호
    • /
    • pp.435-457
    • /
    • 2006
  • The paper presents the cost optimization of composite floor trusses composed from a reinforced concrete slab of constant depth and steel trusses consisting of hot rolled channel sections. The optimization was performed by the nonlinear programming approach, NLP. Accordingly, a NLP optimization model for composite floor trusses was developed. An accurate objective function of the manufacturing material, power and labour costs was proposed to be defined for the optimization. Alongside the costs, the objective function also considers the fabrication times, and the electrical power and material consumption. Composite trusses were optimized according to Eurocode 4 for the conditions of both the ultimate and the serviceability limit states. A numerical example of the optimization of the composite truss system presented at the end of the paper demonstrates the applicability of the proposed approach.

Ferrite 함량변화에 대한 $Ni_{0.5}-A_{0.1}-Zn_{0.4}{\cdot}Fe_2O_4$ Ferrite-Rubber Composite의 전파흡수특성 (Electromagnetic Wave Absorbing Properties of $Ni_{0.5}-A_{0.1}-Zn_{0.4}{\cdot}Fe_2O_4$ Ferrite-Rubber Composite with amounts of a Ferrite)

  • 박연준;신광호;허진;사공건
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2002년도 춘계합동학술대회 논문집
    • /
    • pp.45-49
    • /
    • 2002
  • In this paper, we have studied about electromagnetic wave absorbing properties of ferrite-rubber composite with a variation of ferrite. Amounts of ferrite in a composite absorber were changed from 52 wt.% to 62 wt.%. As a result, it has been shown that the electromagnetic wave absorbing properties of ferrite-rubber composite are related to the amount of ferrite in composite absorber. As a summary, it could be controled the electromagnetic wave absorbing property of ferrite-rubber composite by changing some kinds of annex A and amount of ferrite.

  • PDF

Polyaniline Composite 전극을 사용한 전기 이중층 캐패시터의 전기화학적 특성 (Electrochemical Properties of Electric Double Layer Capacitor with PolyanilineComposite)

  • 강광우;김종욱;구할본
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 1999년도 추계학술대회 논문집
    • /
    • pp.370-373
    • /
    • 1999
  • The purpose of this study is to research and develop PAn composite electrode for EDLC. EDLC cell of PAn composite electrode with 1M LiClO$_4$/PC brings out good capacitor performance below 4.0V. The radius of semicircle of PAn composite electrode adding 15wt% SP270 was absolutely small. The total resistance of EDLC cell mainly depended on internal resistance of the electrode. The discharge capacitance of PAn composite with 15wt% SP270 in 1st and 200th cycles was 42 and 42 F/g at current density of 1mA/cm$^2$. The capacitance of PAn composite with 15wt%. SP270 capacitor was larger than that of PAn capacitor without SP270. The coulombic efficiency of EDLC at discharge process of 1 and 200 cycles were 94 and 100% respectively. PAn composite EDLC with 15wt% SP270 content showed good capacitance and stability with cycling.

  • PDF

유연 복합재료 프로펠러 제작개선 및 성능분석 (Enhanced Manufacturing and Performance Analysis of Flexible Composite Propeller)

  • 이상갑;남재형;현범수;백부근;이창섭;장현길;노인식
    • 대한조선학회논문집
    • /
    • 제49권6호
    • /
    • pp.521-527
    • /
    • 2012
  • It is well known that flexible composite material propeller has superior radiation noise characteristics with outstanding damping effects. In this paper, three flexible composite material propellers were produced using compression molding process, and their hydrodynamic performances and radiation noise characteristics were measured. One propeller, C1, was made up from carbon/epoxy composite laminates, and the other two ones, G1 and G2, from glass/epoxy ones. Their fiber arrays were selected by the progressive damage structural analysis of propellers using composite material model MAT_162 (Composite_DMG_MSC) linked with LS-DYNA code. Carbon/epoxy and glass/epoxy composite specimen tests were performed, their damage mechanisms were figured out, and their parameters were calibrated by their progressive damage structural analysis according to their damage criteria.

Effect of visco-Pasternak foundation on thermo-mechanical bending response of anisotropic thick laminated composite plates

  • Fatima Bounouara;Mohamed Sadoun;Mahmoud Mohamed Selim Saleh;Abdelbaki Chikh;Abdelmoumen Anis Bousahla;Abdelhakim Kaci;Fouad Bourada;Abdeldjebbar Tounsi;Abdelouahed Tounsi
    • Steel and Composite Structures
    • /
    • 제47권6호
    • /
    • pp.693-707
    • /
    • 2023
  • This article investigates the static thermo-mechanical response of anisotropic thick laminated composite plates on Visco-Pasternak foundations under various thermal load conditions (linear, non-linear, and uniform) along the transverse direction (thickness) of the plate, while keeping the mechanical load constant. The governing equations, which represent the thermo-mechanical behavior of the composite plate, are derived from the principle of virtual displacements. Using Navier's type solution, these equations are solved for the composite plate with simply supported condition. The Visco-Pasternak foundation type is included by considering the impact of the damping on the classical foundation model, which is modeled by Winkler's linear modulus and Pasternak's shear modulus. The excellent accuracy of the present solution is confirmed by comparing the results with those available in the literature. The study investigates the impact of geometric ratios, thermal expansion coefficient ratio, damping coefficient and foundation parameters on the thermo-mechanical flexural response of the composite plate. Overall, this article provides insights into the behavior of composite plates on visco-Pasternak foundations and may be useful for designing and analyzing composite structures in practical applications.

Material feature representation and identification with composite surfacelets

  • Huang, Wei;Wang, Yan;Rosen, David W.
    • Journal of Computational Design and Engineering
    • /
    • 제3권4호
    • /
    • pp.370-384
    • /
    • 2016
  • Computer-aided materials design requires new modeling approaches to characterize and represent fine-grained geometric structures and material compositions at multiple scales. Recently, a dual-Rep approach was developed to model materials microstructures based on a new basis function, called surfacelet. As a combination of implicit surface and wavelets, surfacelets can efficiently identify and represent planar, cylindrical, and ellipsoidal geometries in material microstructures and describe the distribution of compositions and properties. In this paper, these primitive surfacelets are extended and composite surfacelets are proposed to model more complex geometries. Composite surfacelets are constructed by Boolean operations on the primitives. The surfacelet transform is applied to match geometric features in three-dimensional images. The composition of the material near the identified features can then be modeled. A cubic surfacelet and a v-joint surfacelet are developed to demonstrate the reverse engineering process of retrieving material compositions from material images.

Crack Propagation at Boundary Face of Composite Compact Tension Specimen

  • Cho, Jae-Ung;Han, Moon-Sik
    • 한국생산제조학회지
    • /
    • 제22권2호
    • /
    • pp.337-341
    • /
    • 2013
  • In this study, fatigue crack propagation in composite material under fatigue is investigated by simulation result. When another material on the specimen exists vertically to the crack line, the phenomena that crack may go straight or propagate along the boundary face according to the elastic modulus ratio of another material to matrix are investigated with compact tension specimen by compliance method. Crack propagation direction is evaluated by compliance method. By arranging this study result systematically about the crack propagation behavior due to the stiffness of inhomogeneous material, high-tech material (automobile, aircraft and steel industry) can be improved. The estimation of safety design and life (construction & nuclear power station, etc.) will be of great value industrially.

Topology optimization of reinforced concrete structure using composite truss-like model

  • Yang, Zhiyi;Zhou, Kemin;Qiao, Shengfang
    • Structural Engineering and Mechanics
    • /
    • 제67권1호
    • /
    • pp.79-85
    • /
    • 2018
  • Topology optimization of steel and concrete composite based on truss-like material model is studied in this paper. First, the initial design domain is filled with concrete, and the steel is distributed in it. The problem of topology optimization is to minimize the volume of steel material and solved by full stress method. Then the optimized steel and concrete composite truss-like continuum is obtained. Finally, the distribution of steel material is determined based on the optimized truss-like continuum. Several numerical results indicate the numerical instability and rough boundary are settled. And more details of manufacture and construction can be presented based on the truss-like material model. Hence, the truss-like material model of steel and concrete is efficient to establish the distribution of steel material in concrete.

기둥의 내진성능 향상을 위한 섬유보강 복합체의 적용성에 대한 해석적 연구 (Numerical Study for Seismic Strengthening of RC columns Using Fiber Reinforced Plastic Composite)

  • 장준호;권민호;김진섭;주치홍
    • 한국구조물진단유지관리공학회 논문집
    • /
    • 제16권3호
    • /
    • pp.117-127
    • /
    • 2012
  • 최근 발생한 대규모 지진으로 구조물의 내진보강에 대한 사회적 관심도가 높아지고 있다. 내진성능 향상을 목적으로 FRP 복합재료의 사용성에 대한 연구 및 개발이 활발히 진행되고 있다. 복합재료를 사용한 내진보강재는 강성과 연성을 가진 재료이어야 하므로 복합재료 보강재 설계 시 강성재와 섬유의 선택이 중요한 변수이다. 내진성능 향상을 위한 섬유보강 복합재료의 최적조합을 인장 테스트를 통하여 선정하였다. 선정된 섬유보강 복합재료 보강재를 실제 구조물에 적용하기 위하여 실제 기둥부재에 보강하는 것을 가정하여 유한요소 해석하였다. 유한요소 해석을 통하여 구조물의 내진성능 향상효과를 변위-하중 관계를 통하여 평가하였다. 섬유보강 복합재료 보강재를 사용할 경우 구조물의 내진성능이 증가한다는 해석적인 연구 결과를 도출하였다.

GFRP 관로의 재료 특성에 관한 실험적 연구 (An Experimental Study of Material Characteristics for GFRP Pipes)

  • 한택희;김성남;강영종;윤기용
    • 한국방재학회 논문집
    • /
    • 제4권2호
    • /
    • pp.35-45
    • /
    • 2004
  • 최근 항공기, 자동차 등에 사용되어왔던 복합재료가 그 사용 영역을 넓혀 교량 상판, 상하수도용 관로 등에 적용되고 있다. 이러한 복합재료의 주요 장점은 고강도, 경량성, 그리고 뛰어난 내부식성으로 기존의 재료에 비해 많은 장점을 갖고 있으나, 이러한 재료의 정확한 특성 파악 및 이를 사용한 구족물의 거동의 정확한 분석의 어려움으로 복합재료의 적용이 활발히 이루어지지 못하고 있는 실정이며, 이러한 요인이 복합재료를 토목구조물에 적용하는데 가장 큰 제한요소로 작용해 왔다. 본 연구에서는 복합재료 구조물의 해석을 위한 사전 연구로서, 현재 국내에서 사용되고 있는 GFRP 관로에 대한 재료특성 실험을 수행하여, 각각의 구성 적층재료별 재료 특성 및 전체 적층판에 대한 재료특성을 제공한다.