• Title/Summary/Keyword: Strip structure

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A finite strip method for elasto-plastic analysis of thin-walled structures under pure bending

  • Cheung, M.S.;Akhras, G.;Li, W.
    • Structural Engineering and Mechanics
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    • v.8 no.3
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    • pp.233-242
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    • 1999
  • In the present study, the elasto-plastic analysis of prismatic plate structures subjected to pure bending is carried out using the finite strip method. The end cross-sections of the structure are assumed to remain plane during deformation, and the compatibility along corner lines is ensured by choosing proper displacement functions. The effects of both the initial geometrical imperfections and residual stresses due to fabrication are included in the combined geometrically and materially nonlinear simulation. The von-Mises yield criterion and the Prandtl-Reuss flow theory of plasticity are applied in modelling the elasto-plastic behavior of material. Newton-Raphson iterations are carried out as the rotation of the end cross sections of the structure is increased step by step. The parameter representing the overall axial strain of structure is adjusted constantly during the iteration process in order to eliminate the resulting overall axial force on any cross-section of the structure in correspondence with the assumption of zero axial force in pure bending. Several numerical examples are presented to validate the present method and to investigate the effects of some material and geometrical parameters.

A Study on the Improvements of Radiation Characteristics of Slot Antenna by Coupling of a Strip Scatterer (스티립형 산란도체에 의한 슬롯안테나의 복사 특성에 관한 연구)

  • Hur, Jung;Lee, Choong-Woong
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.26 no.11
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    • pp.1712-1720
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    • 1989
  • We propose a new radiating structure composed of a strip and a slot excited by an ideal current source, and electromagnetic analysis for the structure is presented. By the analysis procedure which is based upon equivalence formulated. Through the numerical computations to solve the equations by employing the method of moments, we ascertained that the suitable choice of the location and the size of strip guarantee the improvement of the radiation characteristics of antenna.

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Nonlinear Hydroelastic Analysis Using a Time-domain Strip Theory m Regular Waves (규칙파중 시간영역 스트립이론을 이용한 비선형 유탄성 해석)

  • CHO IL-HYOUNG;HAN SUNG-KON;KWON SEUNG-MIN
    • Journal of Ocean Engineering and Technology
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    • v.19 no.4 s.65
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    • pp.1-8
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    • 2005
  • A nonlinear time-domain strip theory for vertical wave loads and ship responses is to be investigated. The hydrodynamic memory effect is approximated by a higher order differential equation without convolution. The ship is modeled as a non-uniform Timoshenko beam. Numerical calculations are presented for the S175 Containership translating with the forward speed in regular waves. The approach described in this paper can be used in evaluating ship motions and wave loads in extreme wave conditions and validating nonlinear phenomena in ship design.

Network Modeling and Circuit Characteristics of Aperture-Coupled Vertically Mounted Strip Antenna

  • Kim, Jeong-Phill
    • Journal of electromagnetic engineering and science
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    • v.11 no.2
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    • pp.122-127
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    • 2011
  • A general analysis of an aperture-coupled vertically mounted strip antenna is presented to examine its circuit characteristics. Based on the present analysis, an equivalent circuit model is developed, and an analytic or semi-analytic evaluation of the related circuit element values is described. The effects of structure parameters on the antenna characteristics were studied with the developed equivalent circuit, and the design curves were obtained. To check the validity of the proposed analysis and design theory, two C-band antennas (5.0 GHz and 4.5 GHz) were designed and fabricated. Their computed characteristics, derived from the proposed network analysis, were compared with the measurement and simulation results. The error of the current model in predicting the operating center frequency was less than 0.50 %. In addition, the observed bandwidth was found to be comparable to the conventional microstrip antennas. All the results fully validated the efficiency and accuracy of the proposed analysis and network model.

Simulation of the Strip Type CNT Field Emitter Triode Structure (띠 모양의 에미터를 가지는 탄소나노튜브 삼전극 전계방출 디스플레이 소자의 시뮬레이션)

  • 류성룡;이태동;김영길;변창우;박종원;고성우;천현태;고남제
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.11
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    • pp.1023-1028
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    • 2003
  • The field emission characteristics are studied by simulation for carbon nanotube triode structures with a strip-shaped emitter and a gate hole aligned with it. Two structures, one with double-edge and the other with single edge are analyzed. They show good emission characteristics. Emissions of electrons are concentrated on the edges of emitter and the emitted current increases as the distance between emitter and gate decreases. For single-edged emitter, the emitted electrons form a narow strip-shaped beam which has a good directionality. These triode structures have advantages in that they can be easily fabricated and aligned for assembly.

Continuity and Transformation of the Cartoon Strip for the Musical Performance (만화 소재 뮤지컬에 있어서 만화특성의 지속성과 변형에 대한 시론적 연구)

  • Yim, Hak-Soon
    • Cartoon and Animation Studies
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    • s.12
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    • pp.27-43
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    • 2007
  • The article concerns the continuity and transformation of the cartoon strip for the musical performance. Recently, the cartoon strip has been considered as a resource for creating the musical performance. However, There are a few articles on the relationship of the cartoon strip and the musical performance. In this respect, the article seeks to examine the characteristics of the cartoon strip and the musical performance in terms of planning system, storytelling structure, character formation and marketing strategies. The case on the musical entitled 'The Great Catsby', which is rooted in the cartoon strip entitled 'The Great Catsby', is examined. As a result, on the one hand, the characteristics of the cartoon strip has continuously affected the process of creating the musical performance in terms of storytelling, character formation, stage management and the marketing activities. On the other hand, the musical performance considers the music and sound, the moving image and stage management, performance of the actors as an essential part in comparison with the cartoon strip. In addition, the musical performance simplifies and recontructs the cartoon strip according to the principles of the musical performance.

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Unsteady Transitional Boundary Layer due to Rotor Stator Interaction at Design and Off Design Operations (설계점 및 탈설계점에서의 rotor-stator 상호작용에 의한 비정상 천이 경계층의 수치해석적 연구)

  • Kang Dong Jin;Jun Hyun Joo
    • Journal of computational fluids engineering
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    • v.4 no.2
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    • pp.17-30
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    • 1999
  • The unsteady transitional boundary layer due to rotor-stator interaction was studied at two operation points, the design and one off design points. The off design point leads to lower blade loading and lower Reynolds number. A Navier-Stokes code developed in the previous study was parallelized to expedite computations. A low Reynolds number turbulence model was used to close the momentum equations. All computations show good agreement with experimental data. The wake induced transitional strip on the suction side of the stator is clearly captured at design point operation. There is no noticeable change in shape and phase angle of the wake induced strip even in the laminar sublayer. The wake induced transitional strip at off design point shows more complex structure. The wake induced transitional strip is observed only in the turbulent layer, and becomes obscure in the laminar sublayer and buffer layer. This behavior is probably consequent upon that the transition is governed by both wake induced strip and natural transition mechanism by Tollmien-Schlichting wave.

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Effects of Alloying Elements and Heat Treatments on the Microstructures and Mechanical Properties of Ductile Cast Iron by Strip Casting (스트립캐스팅한 구상흑연주철박판의 합금원소 및 열처리에 따른 미세조직과 기계적 성질의 변화)

  • Lee, Gi-Rak;Ra, Hyung-Yong
    • Journal of Korea Foundry Society
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    • v.20 no.2
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    • pp.122-128
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    • 2000
  • Strip casting process is a new technology that makes a near net shape thin strip directly from molten metal. With this process, a large amount of energy and casting cost could be decreased from the abbreviation of reheating and/or hot rolling process. Ductile cast iron which has spheroidal graphite in the matrix is the most commercial and industrial material, because of its supreme strength, toughness, and wear resistance etc. But it cannot be produced to the thin strip owing to difficulty in rolling of ductile cast iron. In this study, ductile cast iron strips are produced by the twin roll strip caster, with different chemical compositions of C, Si, and Mn contents. And then heat-treated, microstructures and mechanical properties are examined. The microstructures of as-cast strip are that of white cast iron which consists of the mixture of cementite and pearlite, but the equiaxed crystal zone of the pearlite or segregation zone of cementite exists in the center region of the strip thickness, which cannot be observed in the rapidly solidified metallic mold cast specimens. This structure is supposed to be formed from the thermal distribution of strip and the rolling force. Comparing with the structures of each strips after heat treatment, increasing Si content makes smaller spheroidal graphite and more compact in the matrix, furthermore the less of Mn content makes the ferrite matrix be obtained clearer and easier. As a result of the tensile test of graphitization heat-treated strips, the yield strengths are about 250 MPa, the tensile strengths are about $430{\sim}500$ MPa, and the elongations are about $10{\sim}13%$. In the case of the strip which has the smaller and more compact spheroidal graphite in the ferrite matrix, the higher tensile strength and better drawability could be obtained.

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A Study of Highly Miniaturized On-Chip Wilkinson Power Divider Employing Periodic Strip Structure for Application to Silicon RFIC (실리콘 RFIC상에 주기적 스트립 구조를 이용한 초소형 온칩용 윌킨슨 전력분배기 개발에 관한 연구)

  • Ju, Jeong-Gab;Yun, Young
    • Journal of Advanced Marine Engineering and Technology
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    • v.34 no.4
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    • pp.540-546
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    • 2010
  • In this study, using a coplanar waveguide employing Periodic Strip Structure (PSS), highly miniaturized on-chip wilkinson power divider was realized on Si radio frequency integrated circuit (RFIC). The wilkinson power divider exhibited good RF performances from 25 to 50 GHz, and its size was $0.44{\times}0.1mm^2$, which is 4.8 % of conventional one. We also investigated the RF performances of various structures employing PSS.