• Title, Summary, Keyword: 수평안정판

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Improvement of Flight Safety by Horizontal Stabilizer Design Improvement of Rotorcraft (회전익 항공기 수평 안정판의 설계 개선을 통한 비행 안전성 향상)

  • Lee, Yoon-Woo;Kim, Dae-Han;Jang, Min-Wook;Hyun, Young-Jin;Lee, Sook
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.6
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    • pp.134-141
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    • 2019
  • This paper is a study on design improvement of rotorcraft horizontal stabilizer. The rotorcraft horizontal stabilizer stabilizes the behavior of the pitch, yaw, etc. from the aircraft. Because of this role, horizontal stabilizers are a major component (Flight Safety Part) that affects flight safety on rotorcraft. However, when the rotorcraft was operated in domestic, cracks were found in the inner structure of the horizontal stabilizer and design improvement was needed. In this paper, we identified the two causes of the horizontal stabilizer crack defects through fracture analysis and structural analysis. The first is the tightening torque when the bolt is tightened, and the second is the lead-lag behavior of aircraft. In order to improve these two causes, bolt fastening method, flange structure and thickness were changed and composite ring was applied. In order to verify the design improvement, the structural analysis was performed and the structural strength was improved. Also Fatigue analysis of the internal structure (Rib 1) was performed and it was confirmed that the requirements were satisfied.

Stability Analysis of Reinforced Retaining Wall with Steel Supported Face (강재지주 전면판 보강토 옹벽의 안정성 평가)

  • Kim, Ki Il;Kim, Byoung Il;Lee, Yeong Saeng;Lee, Soon Ho
    • Journal of The Korean Society of Civil Engineers
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    • v.31 no.2C
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    • pp.75-82
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    • 2011
  • Recently, a new reinforced retaining wall with light steel support face has been developed. In this study, full size in-situ test is carried out to investigate the stability of the new reinforced retaining wall. The lateral displacement of wall, lateral earth pressure, and settlement of the reinforced retaining wall are measured in the full size test. And numerical analysis by 3-D finite element method is also carried out to compare the test results with those of the analysis. From the full size in-situ test, the maximum lateral displacement of wall is 46mm(0.009H) and the maximum settlement is 21.5mm. And comparing these values with those of numerical analysis, it is confirmed that the new reinforced retaining wall with light steel support face is stable and applicable.

Design of Composite Laminates by Consideration of Manufacturability (제작성을 고려한 복합적층판의 설계)

  • 김정석;김천곤;홍창선
    • Proceedings of the Korean Society For Composite Materials Conference
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    • pp.264-267
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    • 1999
  • 복합적층판은 일반적으로 균일한 두께를 갖는 평평한 구조물을 형성하게 된다. 그러나 실제 적용시 적층판의 테이퍼링(tapering)이 요구되는 경우가 존재한다. 테이퍼진 복합재 구조물의 적용분야는 항공기의 날개, 수직/수평 안정판 및 헬리콥터의 로터 블레이드 등이다. (중략)

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Mechanical Characteristics of Laminated Rubber Bearings for Seismic Isolation (면진용 적층고무베어링의 기계적 역학특성)

  • Koo, Gyeong-Hoi;Lee, Jae-Han;Yoo, Bong
    • Journal of the Earthquake Engineering Society of Korea
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    • v.1 no.2
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    • pp.79-89
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    • 1997
  • The objective of this paper is to investigate the mechanical characteristics of the laminated rubber bearings (LRBs) for the seismic isolation. The evaluations of the proposed equations of the LRB horizontal stiffness are carried out and these equations are extended to the visco-elastic problems to investigate the damping amplifications of LRBs. The stability evaluation of LRBs is also performed. For investigation of the dynamic characteristics of LRBs, the horizontal stiffness equations of the LRBs considering the P-delta effects are applied to the modeling of a seismically isolated structure and the earthquake response time history analyses are carried out. From this research, the proposed simple equation of the horizontal stiffness of LRB is so useful for the design loads and easily extended to the visco-elastic problems. Through the stability evaluation of LRB, the increasing ratio of the total rubber thickness of the LRB severely decrecises the bucking load than the increasing ratio of unit rubber thickness. From the comparison of the dynamic shear deflection of LRB, the analysis results are in good agreement with those of the experiments.

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Dynamic Stability Analysis of a Submarine by Changing Conning Tower Position and Control Planes (잠수함의 Conning Tower 위치 및 제어판 형태에 따른 동적 안정성 분석)

  • Han, Ji-Hun;Jeong, Jae-Hun;Lee, Seung-Bum;Jang, Keun-Young;Lee, Seung-Keon
    • Journal of Navigation and Port Research
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    • v.41 no.6
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    • pp.389-394
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    • 2017
  • In this paper, the captive model test of a submarine using the RA test was carried out in a square basin. The target model submarine consisted of four types varying according to the position of conning tower and control planes. Hydrodynamic derivatives were acquired by multi-regression analysis. As a result, horizontal dynamic stability indexes of the four types presented positive values and satisfied dynamic stability requirements. In addition, the stability index of type 1 and type 4 - each with the same cruciform configuration of the aft planes - scored within the acceptable range of motion stability.

Elastic Stability of Perforated Concrete Shear Wall (개구부를 갖는 콘크리트 전단벽의 탄성안정)

  • 김준희;김순철
    • Computational Structural Engineering
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    • v.11 no.1
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    • pp.251-259
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    • 1998
  • Concrete shear wall with opening is modeled as a rectangular thin plate. The stability analysis results are presented by the buckling coefficient, k, for two different boundary conditions. The other parameters whose variation have been considered are the ratio of the bending induced force to gravity force, a, the ratio of the horizontal shear force to the gravity force ratio, A and the change of location and the size of perforated part. To obtain the results by finite element method, an example plate has been divided into 27*9 square elements. Four node rectangular c.deg. continuous finite elements having three degrees of freedom per each node is adopted. It is generally concluded that the buckling coefficients decrease as the size of hole increases, and the location of hole moves to free edge of the wall.

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Application of Horizontal Flow Fins Inclined Plate for Sedimentation Efficiencies Improvement in River Water with High Turbidity (고탁도 원수의 침전효율 증대를 위한 수평류식 핀 경사판 적용에 관한 연구)

  • Choi, Jung-Su;Jin, Oh-Suk;Joo, Hyun-Jong
    • Journal of Korean Society of Environmental Engineers
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    • v.34 no.9
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    • pp.644-650
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    • 2012
  • The purpose of this study is to evaluate the applicability of Horizontal Flow Fins Inclined Plate (HFIP) for the removal of high-turbidity raw water in water treatment plant. As an experimental result, treated water quality and removal efficiency were 0.34 NTU and 90.45% by the application of HFIP for low-turbidity raw water and for the high-turbidity influent resulted 0.75 NTU and 97.27% in removal efficiency. In view of stability for discharge water NTU, the standard deviation were found as 0.12 NTU for low-turbidity and 0.75 NTU for high-turbidity raw water indicating low fluctuations. Result of flow analysis using CFD (Computational Fluid Dynamic) that the addition of HFIP improves the turbidity treatment followed by the stabilization of flow velocity distribution and increases in settling velocity.

The Evaluation of Stability for Hook-type Bonding Method of Pile Foundation and Cap (훅타입 말뚝두부보강 기초의 안정성 평가)

  • Lee, Heunggil;Oh, Sewook
    • Journal of the Korean GEO-environmental Society
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    • v.8 no.3
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    • pp.41-49
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    • 2007
  • The typical bonding methods which connect steel pipe pile and spread footing is bolted bonding method using +type cover plate for reinforcing a head of steel pipe pile. In this paper, stability of spread footing in pile foundation have been evaluated by loading test of +type cover plate for reinforcing a head of pile and hook type bonding method. The presents results from a series of pilot model test on vertically loaded piles foundation of bolted bonding method and hook type bonding method, pile foundation is identified to safety due to pile foundation exceed 8.5~21% which more than yield stress of steel pipe pile. As the results of horizontal loading tests, peak load of piles foundation of hook type bonding method has estimated in 41.1tonf and it was exceed about 33% which more than pile foundation of bolted bonding method.

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A Study on the Deformation Characteristics of the Roof Signboard Size in Wind Pressure Formation (풍압 형성에 따른 옥상광고판 크기별 특성에 관한 연구)

  • Hong, Ji-Wan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.1
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    • pp.401-408
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    • 2019
  • This study numerically examined the maximum wind pressure distribution of a billboard on the roof of a middle-rise building. The deformation caused by the maximum wind pressure was examined. For the numerical analysis, the signboard was assumed to be installed on $(b)20m{\times}(d)10m{\times}(h)$ buildings. The maximum wind pressure was measured using four models with the standard model and different sizes of the signboard. The numerical analysis showed that the horizontal deformation predominantly occurs as the shape of the signboard becomes closer to a rectangle, and high wind pressure and deformation occur at the corners of both ends. As the height of the signboard increases, vertical deformation predominantly occurs, and static pressure forms on the backside. When the height is lower than the width of the signboard, the wind pressure is concentrated on the center of the roof. Therefore, the distribution of the maximum wind pressure is stable, and the effect of the wind pressure is relatively low as the height-to-width ratio approaches 1.

Design and Analysis on The Connections of RC Precast Large Panel (철근콘크리트 프리캐스트 대형판 접합부의 설계 및 해석)

  • Park, Kang-Geun
    • Journal of Korean Association for Spatial Structures
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    • v.6 no.2
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    • pp.85-92
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    • 2006
  • Precast large panel structures have various connection system such as the horizontal slab-to-wall connection, the vertical wall to wall connection, horizontal slab-to-slab connection, etc. Horizontal connection is connected by vertical tie bars, and vertical joint is connected loop bars and shear keys. The basic function is equalized deformations on later forces and the entire wall panel assembly acts as monolithic actions. Under lateral load some slip occurs in almost vertical connections. The shape and detail of precast connections are very important to the monolithic behavior of overall structures. The paper is a study on the design method and new elasto-plastic analysis of the connections by rigid-bodies spring model.

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