• Title/Summary/Keyword: Helicopter Landing Gear

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Dynamic Analysis of a Helicopter Landing Gear with Considering Flexible Structural Modes (동체의 유연성을 고려한 헬기 착륙장치의 동특성 해석 연구)

  • Hyun, Young-O;Bae, Jae-Seoung;Kim, Young-Seok;Hwang, Jae-Up;Lim, Kyoung-Ho;Kim, Doo-Man;Kim, Tae-Wook;Hwang, Jai-Hyuk
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.15 no.4
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    • pp.33-37
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    • 2007
  • In this paper, a dynamic analysis of a helicopter landing gear with considering flexible structural modes has been investigated. The main body of the helicopter has been modeled as a flexible body using FEM code, then a few selected vibration modes of the helicopter main body have been used as basis for the dynamic analysis of the helicopter landing gear. The simulation of dynamic analysis was carried out on the base of ADAMS aircraft module. It has been found by a series of simulation that the flexible structural modes has a significant effect on the dynamic characteristics of helicopter landing gear as the flexibility of the main body is increased.

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Nonlinear Crash Analyses and Comparison with Experimental Data for the Skid Landing Gear of a Helicopter (헬리콥터 강착장치 비선형 충돌해석 및 실험결과 비교)

  • 이상민;김동현;정세운
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.8
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    • pp.87-94
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    • 2006
  • In this study, nonlinear crash analyses have been conducted for the skid landing gear of a helicopter. The realistic landing gear model of the commercial helicopter (SB427) is considered. Three-dimensional dynamic finite element model with variable thickness and material plastic behavior is constructed and LS-DYNA(Ver.970) is used to conduct nonlinear transient crash analyses for different impact conditions. Characteristics of nonlinear transient responses due to the ground crash are investigated for typical structural design criteria of a skid landing gear system. In addition, comparison results for maximum crash deformations of the skid landing gear are presented and the important effect of ground friction for numerical accuracy is described.

Impact Dynamic Analysis for the Wheel-Type Landing Gear System of Helicopter (헬리콥터 휠타입 착륙장치 충돌특성 연구)

  • Park, Hyo-Geun;Kim, Dong-Man;Kim, Dong-Hyun;Cho, Yun-Mo;Chung, Jae-Hoon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.5
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    • pp.12-22
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    • 2008
  • In this study, the dynamic characteristics for the wheel-type landing gear system of helicopter have been analyzed. Nonlinear multi-body dynamic models of the landing gear system are constructed and the equations of motion, kinematics and internal forces of shock strut are considered. In addition, flexibility effect of the wheel axle with equivalent beam element is taken into account. General purpose commercial finite code, SAMCEF which includes MECANO module is applied. The results of dynamic simulation for various landing and weight conditions are presented and compared with each other. Based on the results, characteristics of impact dynamic behaviors of the landing gear system are practically investigated.

Dynamic Characteristics Analysis of Landing Gear that Consider 6-Degree of Freedom of Helicopter (6자유도를 고려한 회전익 항공기 착륙장치의 동특성 해석)

  • Park, Wansoo;Hwang, Jaeup;Hyun, Youngho;Hwang, Jaehyuk;bae, Jaeseoung;Kim, Taewook
    • Journal of Aerospace System Engineering
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    • v.2 no.1
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    • pp.1-6
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    • 2008
  • In this paper, full body modeling and analysis of nose and main landing gear's characteristics of a helicopter are performed using the dynamics analysis program ADAMS. Also, when land limiting about helicopter body's degree-of-freedom, compared the characteristics. In the case of helicopter, because there are a lot of dangerous missions under flight condition that is disadvantageous than fixed wing airplane, need more detailed research for a helicopter.

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Semi-Active Control of Helicopter Landing Gear using Magneto-Rheological Damper (MR 댐퍼를 이용한 헬기 착륙장치 반능동제어)

  • Hwang, Jae-Up;Hwang, Jae-Hyuk;Bae, Jae-Sung;Hyun, Young-O;Lim, Kyoung-Ho;Kim, Doo-Man;Kim, Tae-Wook
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.36 no.4
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    • pp.346-351
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    • 2008
  • In this paper, the semi-active control of a helicopter landing gear using magneto -rheological(MR) damper is studied. A dynamic model of the MR damper is formulated by incorporating magnetic field-dependent Bingham properties of the MR fluid. The electromagnet of the MR damper is designed and its magnetic field is analyzed using a commercial finite element code. The damping characteristics of MR damper by changing the intensity of the magnetic field are investigated and the dynamic responses of the helicopter landing gear with MR damper are simulated. The semi-active control of the helicopter landing gear is simulated by implementing a sky-kook control algorithm and its performance is evaluated comparing to the passive control.

A Study on the Behavior of Skid Gear During the Helicopter Autorotation (헬리콥터 오토로테이션시 착륙장치 거동에 관한 연구)

  • Choi, Hyung-Tai;Oh, Jung-Jin;Kim, Geun-Won;Shin, Ki-Su
    • Journal of the Korea Institute of Military Science and Technology
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    • v.15 no.6
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    • pp.746-753
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    • 2012
  • ROK military helicopters are frequently exposed to the hazard situations due to the characteristic of operation. Especially, helicopter accident may lead to critical damage of human and structure. Accordingly, pilots have to train the autorotation procedures and learn the skill to prevent hard landing. In this paper, the behavior of skid gear subject to the helicopter autorotation was conducted by using numerical method. The computer simulation approach by using finite element method was employed to accomplish this goal. Additionally, the behavior of skid gear was evaluated for the different landing conditions. In conclusion, the maximum stress concentration was occurred at the attached area of skid cross-tube to the fuselage. Also, it was revealed that the most proper attitude was level landing to prevent hard landing.

Drop Test Simulation of semi-active Landing Gear using Commercial Magneto-Rheological Damper (상용 MR 댐퍼를 이용한 반능동형 착륙장치 낙하실험)

  • Hwang, Jae-Up;Hwang, Jae-Hyuk;Bae, Jae-Sung;Lim, Kyoung-Ho
    • Journal of Aerospace System Engineering
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    • v.4 no.4
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    • pp.44-48
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    • 2010
  • This paper is used the commercial magneto-rheological(MR) damper for landing gear. The damping characteristics of Commercial MR damper by changing the intensity of the magnetic field are investigated and the dynamic responses of the landing gear. it is set up tset equipment, the landing gear drop test system. The landing gear involved drop testing the gear. The landing gear is tested by implementing sky-hook control algorithm and its performance is evaluated comparing to the result.

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Helicopter Landing Gear Ground Reaction Simulation (헬리콥터 강착장치 시뮬레이션)

  • 최형식;전향식;오경륜;배중원;남기욱
    • Proceedings of the Korea Society for Simulation Conference
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    • 2004.05a
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    • pp.131-135
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    • 2004
  • Landing gear force reaction module is important for aircraft take off and landing simulation. But usually this modulo is not accounted for control law design simulation. because it does not affect the flying quality of aircraft. Now a days, this module is getting more important according to the increase of needs for training purpose simulation and specific control law design such as unmaned aircraft landing on the moving platform. In this paper 1DOF mass spring simple force system per gear was accepted.

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The Analysis and the Qualification Test Procedures for Oleo-pneumatic Landing Gear (유공압 착륙장치 해석 및 시험평가)

  • Kim, Tae-Uk;Lee, Sang-Wook;Kim, Sung-Chan
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.20 no.2
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    • pp.7-12
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    • 2012
  • A landing gear absorbs the impact energy during the touchdown and it generally consists of an oleo-pneumatic shock absorber and structural components. It should be designed not only to satisfy the static and fatigue strength requirements but to have the sufficient shock absorbing efficiency. The design loads and shock absorbing performance are to be validated by tests, which is required by MIL Spec and FAR, etc. This paper presents the development procedures from the design requirements to the qualification tests and technical points to be considered, with examples of the helicopter landing gear development.

Force Control of Main Landing Gear using Magneto-Rheological Damper (MR 댐퍼를 이용한 주륜 착륙장치 하중제어기법 연구)

  • Hyun, Young-O;Hwang, Jae-Up;Hwang, Jae-Hyuk;Bae, Jae-Sung;Lim, Kyoung-Ho;Kim, Doo-Man;Kim, Tae-Wook
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.4
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    • pp.344-349
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    • 2009
  • To improve performance of the main landing gear for helicopters, a semi-active control landing gear is introduced in this paper. An MR damper based on commercial finite element electromagnetic field analysis of an electromagnet has been adapted the shock absorber. Force control algorithm (which maintains constantly the sum of air spring force and damping force as internal forces) which keep the sum of air spring force and damping force constant during landing, has been used for the controller, applied to control the semi-active landing gear. A series of drop simulations using ADAMS has been done with the passive, sky-hook control type, and force control type landing gears. The result of each simulation has been compared to evaluate the landing performance of the proposed force control type landing gear.