• 제목/요약/키워드: Material thickness

검색결과 5,541건 처리시간 0.035초

Static analysis of non-uniform heterogeneous circular plate with porous material resting on a gradient hybrid foundation involving friction force

  • Rad, A. Behravan;Farzan-Rad, M.R.;Majd, K. Mohammadi
    • Structural Engineering and Mechanics
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    • 제64권5호
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    • pp.591-610
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    • 2017
  • This paper is concerned with the static analysis of variable thickness of two directional functionally graded porous materials (FGPM) circular plate resting on a gradient hybrid foundation (Horvath-Colasanti type) with friction force and subjected to compound mechanical loads (e.g., transverse, in-plane shear traction and concentrated force at the center of the plate).The governing state equations are derived in terms of displacements based on the 3D theory of elasticity, assuming the elastic coefficients of the plate material except the Poisson's ratio varying continuously throughout the thickness and radial directions according to an exponential function. These equations are solved semi-analytically by employing the state space method (SSM) and one-dimensional differential quadrature (DQ) rule to obtain the displacements and stress components of the FGPM plate. The effect of concentrated force at the center of the plate is approximated with the shear force, uniformly distributed over the inner boundary of a FGPM annular plate. In addition to verification study and convergence analysis, numerical results are displayed to show the effect of material heterogeneity indices, foundation stiffness coefficients, foundation gradient indices, loads ratio, thickness to radius ratio, compressibility, porosity and friction coefficient of the foundation on the static behavior of the plate. Finally, the responses of FG and FG porous material circular plates to compound mechanical loads are compared.

물질의 광학적 두께에 따른 EMP-simulation을 통한 광특성 대조 (The Comparison of Optical Properties with Different Optical Thickness of Materials by EMP-simulation)

  • 장강재;장건익;이남일;정재일;임광수
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.345-345
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    • 2007
  • ZnS/$Na_3AlF_6$/ZnS/Cu multi-layered thin film were simulated by EMP. EMP is a comprehensive software package for the design and analysis of optical thin film. ZnS and $Na_3AlF_6$ was selected as a high refractive index material and low refractive index material And Cu was selected as mid reflective material. Optical properties including color effect were systematically studied in terms of different low refractive index materials thickness. $Na_3AlF_6$ were changed 0.25, 0.5, 0.75, $1.0{\lambda}$. The thin film showed $0.25{\lambda}$ : blue, purple / $0.5{\lambda}$ : yellow $0.75{\lambda}$ : blue, purple, red / $1.0{\lambda}$ : yellow, green, blue, purple. It was becaused by different optical thickness of $Na_3AlF_6$. The maximum of optical interference by refractive layer.

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전자 주입층의 두께 변화에 따른 OLEDs의 전기적 특성 (Electrical Properties of OLEDs depending on Thickness variation of Electron Injection Layer)

  • 차기호;이영환;이종용;정동회;신종열;김태완;홍진웅
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2006년도 하계학술대회 논문집 Vol.7
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    • pp.69-70
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    • 2006
  • We studied increasement of efficiency of Organic Light-emitting Diodes depending on thickness variation of LiF, Material of Electron Injection Layer in structure of ITO/Hole Injection Layer (PTFE)/Hole Transportion Later (TPD)/Emitting Layer (Alq3)/Electron Injection Layer (LiF)/Al. TPD and $Alq_3$ is deposited as rate of 1.3~1.5 [${\AA}/s$] in high vacuum ($5{\times}10^{-6}$ [torr]). In result of these studies, we can know maximum efficiency in 0.7 [nm], thickness of LiF. And samples with electron injection material are increased about 5-fold in maximum efficiency in compare with sample without electron injection material.

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소수성 특성을 이용한 저점도 AP 표면처리재의 현장 적용성 연구 (A Study on Field Applicability Evaluation of the Hydrophobic - Low Viscosity Surface Treatment Material for Pavement Preventive Maintenance)

  • 최준성
    • 한국도로학회논문집
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    • 제16권1호
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    • pp.31-39
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    • 2014
  • PURPOSES : Surface treatment material for pavement preventive maintenance should be inspected field applicability. This study(Part II) aimed to checkup coating characteristics and performance analysis using lab and field tests. The hydrophobic - low viscosity filling material for pavement preventive maintenance is presented in Part I, which is a series of companion study. METHODS : Relative comparison between general asphalt mixtures and surface treatment asphalt mixtures are analyzed and measured for the field application such as indirect tensile strength ratio(TSR), abrasion resistance, crack propagation resistance, temperature resistance, coating thickness, permeability resistance and skid resistance in terms of british pendulum number(BPN). RESULTS : It is found that TSR, crack propagation resistance and permeability resistance is increased as against uncoated asphalt specimen. Abrasion resistance and temperature resistance is secured from the initial coating thickness point of view, which is about 0.2~0.3mm. Skid resistance on the surface treatment pavement is satisfied with the BPN criteria of national highway because of exposed aggregate and crack sill induced pavement deterioration and damage cracks. CONCLUSIONS : The hydrophobic - low viscosity surface treatment material for pavement preventive maintenance is validated on field applicability evaluation based on quantitative analysis of coating thickness and performance analysis using lab and field tests.

Investigation on thermal buckling of porous FG plate resting on elastic foundation via quasi 3D solution

  • Mekerbi, Mohamed;Benyoucef, Samir;Mahmoudi, Abdelkader;Bourada, Fouad;Tounsi, Abdelouahed
    • Structural Engineering and Mechanics
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    • 제72권4호
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    • pp.513-524
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    • 2019
  • The present article deals with thermal buckling of functionally graded plates with porosity and resting on elastic foundation. The basic formulation is based on quasi 3D theory. The present theory contains only four unknowns and also accommodates the thickness stretching effect. Porosity-dependent material coefficients of the plate are compositionally graded throughout the thickness according to a modified micromechanical model. Different patterns of porosity distributions are considered. The thermal loads are assumed to be uniform, linear and non-linear temperature rises through the thickness direction. The plate is assumed to be simply supported on all edges. Various numerical examples are given to check the accuracy and reliability of the present solution, in which both the present results and those reported in the literature are provided. In addition, several numerous new results for thick FG plates with porosity are also presented.

소스/드레인 전극의 두께변화에 따른 TIPS-pentacene 트랜지스터의 전기적 특성 연구 (Study on die electric characteristics of TIPS-pentacene transistors with variation of electrode thickness)

  • 양진우;형건우;김영관
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 하계학술대회 논문집
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    • pp.323-324
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    • 2009
  • We investigated the electrical properties of tris-isopropylsilylethynyl (TIPS)-pentacene organic thin-film transistors (OTFTs) employing Ni/Ag source/drain electrodes. The gap height between the gate insulator and S/D electrode was controlled by changing the thickness of Ag under-layer(20, 30, 40 and 50nm). After evaporating the Ni under-layer, TIPS pentacene channel material was dropping the gap between the gate insulator and SID electrodes. The electrical proprieties of OTFT such as filed-effect mobility, on/off ratio, threshold voltage and subthreshold slope were significantly influenced by the gap height.

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Numerical Analysis of Through Transmission Pulsed Eddy Current Testing and Effects of Pulse Width Variation

  • Shin, Young-Kil;Choi, Dong-Myung
    • 비파괴검사학회지
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    • 제27권3호
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    • pp.255-261
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    • 2007
  • By using numerical analysis methods, through transmission type pulsed eddy current (PEC) testing is modeled and PEC signal responses due to varying material conductivity, permeability, thickness, lift-off and pulse width are investigated. Results show that the peak amplitude of PEC signal gets reduced and the time to reach the peak amplitude is increased as the material conductivity, permeability, and specimen thickness increase. Also, they indicate that the pulse width needs to be shorter when evaluating the material conductivity and the plate thickness using the peak amplitude, and when the pulse width is long, the peak time is found to be more useful. Other results related to lift-off variation are reported as well.

Thermo-mechanical bending response with stretching effect of functionally graded sandwich plates using a novel shear deformation theory

  • Saidi, Hayat;Houari, Mohammed Sid Ahmed;Tounsi, Abdelouahed;Bedia, El Abbas Adda
    • Steel and Composite Structures
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    • 제15권2호
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    • pp.221-245
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    • 2013
  • This paper presents an analytical solution to the thermomechanical bending analysis of functionally graded sandwich plates by using a new hyperbolic shear deformation theory in which the stretching effect is included. The modulus of elasticity of plates is assumed to vary according to a power law distribution in terms of the volume fractions of the constituents. The core layer is still homogeneous and made of an isotropic ceramic material. The effects of functionally graded material (FGM) layer thickness, volume fraction index, layer thickness ratio, thickness ratio and aspect ratio on the deflections and stresses of functionally graded sandwich plates are investigated.

십자형 필릿 용접부에서 재료 두께 및 용접 층수에 따른 피로파괴 특성 (Characteristics of Fatigue Failure according to Thickness of Material and Number of Passes in Cruciform Fillet Weld Zone)

  • 이용복
    • Journal of Welding and Joining
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    • 제28권6호
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    • pp.45-50
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    • 2010
  • Most of joining processes for machine and steel structure are performed by butt and fillet welding. The mechanical properties and fatigue strength of their welding zone can be effected largely by the differential of generated heat and changes of grain size according to thickness of material and number of passes in welding process. In this study, it was investigated about characteristics of fatigue failure according to thickness of material and number of passes in cruciform fillet weld zone as the basic study for safe and economic design of welding structures. Fracture modes in cruciform fillet weld zone are classified into toe failure and root failure according to non-penetrated depth. It can be accomplished economic design of welding structures considering fatigue strength when the penetrated depth in fillet weld zone is controled properly.

주석 및 아연 박막이 코팅된 베어링 표면의 구름 저항 거동에 대한 실험적 고찰 (An Experimental Study on the Rolling Resistance of Bearing Surfaces Coated by Pure Tin and Zinc Films)

  • 양승호;공호성;윤의성;김대은
    • Tribology and Lubricants
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    • 제14권1호
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    • pp.1-6
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    • 1998
  • An experimental study was performed to discover the tribological behaviors of pure tin and zinc coated 52100 bearing steel. Pure tin coatings ranging from 30 nm to 30,000 nm and pure zinc coatings ranging from 500 nm to 52,000 nm were produced by a thermal evaporation coating method. Experiments using a thrust ball bearing-typed rolling test-rig were performed for the investigations of the effect of coating thickness on the tribological rolling behavior. Results showed that the existence of optimum film thickness which revealed minimum rolling resistance was discovered for tin and zinc coating. The compatibility of coating material to iron showed no significant effect on the rolling resistance behavior. The hardness of coating material revealed significant influence to the rolling resistance behavior.