• Title/Summary/Keyword: landing dynamic

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Evaluation of Landing Impact Force of Court Sport Shoes at Running by Finite Element Analysis (유한요소 해석을 통한 코트 스포츠화의 런닝시 충격력 평가)

  • Kim, Seong-Ho;Cho, Jin-Rae;Ryu, Sung-Heon;Choi, Joo-Hyung
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.498-503
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    • 2004
  • A fundamental function of court sport shoes has been considered as the protection of human feet from unexpected injuries. But, recently its role for improving the playing competency is being regarded as a more important function. In connection with this situation, intensive efforts are being world-widely forced on the development of court sport shoes proving the excellent playing competency, by taking kinesiology and biomechanics into consideration. However, the success of this goal depends definitely on the shoes design based upon the reliable evaluation of shoes functional parts. This paper addresses the application of finite element method to the evaluation of landing impact force of court sport shoes. In order to reflect the coupling effect between leg and shoes accurately and effectively, we construct a fully coupled shoes-leg FEM model which does not rely on the independent experimental data any more. Through the numerical experiments, we assess the reliability of the coupled FEM model by comparing with the experimental results and investigate the landing impact characteristics of court sport shoes.

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Evaluation of Landing Impact Force of Court Sport Shoes by Finite Element Method (유한요소법을 이용한 코트 스포츠화의 착지 충격력 평가)

  • Kim, Seong-Ho;Ryu, Sung-Heon;Choi, Joo-Hyung;Cho, Jin-Rae
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.11
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    • pp.1786-1793
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    • 2004
  • A fundamental function of court sport shoes was considered as the protection of human feet from unexpected injuries. But, recently its role for improving the playing competency has been regarded as of more importance. In connection of this situation, intensive efforts are world-widely forced on the development of court sport shoes proving the excellent playing competency by taking kinesiology and biomechanics into consideration. However, the success of this goal depends definitely on the shoes design based upon the reliable evaluation of shoes functional parts. This paper addresses the application of finite element method to the evaluation of landing impact force of court sport shoes. In order to reflect the coupling effect between leg and shoes accurately and effectively, we construct a fully coupled shoes-leg FEM model which does not rely on the independent experimental data any more. Through the numerical experiments, we assess the reliability of the coupled FEM model by comparing with the experimental results and investigate the landing impact characteristics of court sport shoes.

Trade-Off Study of Shipboard Landing of Vertical Take-off and Landing Aircraft (수직이착륙 항공기의 함상이착륙 사례분석)

  • Yoo, Chang-Sun;Cho, Am;Park, Bun-Jin;Kang, Young-Shin
    • Aerospace Engineering and Technology
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    • v.12 no.1
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    • pp.10-21
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    • 2013
  • As helicopter technology has been upgraded, today its oceanic operation is considered to be usual. In oceanic operation of helicopter, the effect of severe wind, wave, and corrosion must be investigated and the operation procedures for safety as well as the motion of shipboard arising from maneuvers of ship must also be considered. In this paper, it describes the result of trade-off study for shipboard landing and its operation procedure including dynamic interface between ship and aircraft in ship operation and gives a simulation results to implement the oceanic operation of tilt rotor aircraft.

Evaluation of Landing Impact Characteristics of Sport Shoes in Running by finite Element Analysis (유한요소 해석을 통한 스포츠화의 런닝 시 착지충격 특성평가)

  • Kim, Sung-Ho;Cho, Jin-Rae;Lee, Shi-Bok;Park, Seung-Bum
    • Korean Journal of Applied Biomechanics
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    • v.19 no.2
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    • pp.217-225
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    • 2009
  • Recently, intensive research efforts are world-widely forced on the development of sport shoes improving both the injury protection and the playing performance by taking kinesiology and biomechanics into consideration. However, the success of this goal depends definitely on the reliable evaluation of the dynamic responses of sport shoes and human foot, particularly the landing impact characteristics. It is because the landing impact force is a main source of unexpected injuries and influences the playing performance in court sport activities. This paper addresses the application of finite element method to the evaluation of landing impact characteristics of barefoot and several representative court sport shoes in running. In order to accurately reflect the coupling effect between human foot and shoes accurately, we construct a fully coupled three-diemensional foot-shoe FEM model which does not rely on the independent experimental data any more. Through the numerical simulation, we assessed the reliability of the numerical FEM model by comparing with the experimental results and investigated the landing impact characteristics, such as GRF, MIF, acceleration and frequency responses, of representative court sport shoes.

Modeling of MR Damper Landing Gear Considering Incompletely Developed Fluid Flow (불완전 발달 유체 유동을 고려한 MR댐퍼 착륙장치 모델링)

  • Lee, Hyo-Sang;Jang, Dae-Sung;Hwang, Jai-Hyuk
    • Journal of Aerospace System Engineering
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    • v.15 no.1
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    • pp.7-18
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    • 2021
  • A semi-active MR damper landing gear is a damper that generates a fluid damping force and a magnetic field control damping force when the MR fluid passes through annular flow paths. In the case of MR fluid passing through annular flow paths, an incompletely developed flow inevitably occurs, causing an error in calculating damper inner forces including the fluid damping force. This error results in an inaccurate design of damper structural parameters and control gain selection, resulting in deterioration of dynamic characteristics and shock absorption performance of the landing gear. In this paper, we derived a mathematical model of an MR damper landing gear considering additional damping force generated in the entrance region of annular flow paths of the MR damper. If the mathematical modeling derived from this paper is applied to the design and optimization process of an MR damper landing gear, excellent performance of the MR damper landing gear is expected.

Hybrid Control of Aircraft Landing Gear using Magnetorheological Damper (MR댐퍼를 적용한 항공기 착륙장치의 하이브리드 제어기법 연구)

  • Tak, Jun Mo;Viet, Luong Quoc;Hwang, Jai-Hyuk
    • Journal of Aerospace System Engineering
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    • v.12 no.1
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    • pp.1-9
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    • 2018
  • In this study, a hybrid control method that adjusts for the existing force control technique has been presented for consideration. The proposed hybrid control technique does away with the chattering phenomenon occurring in existing force control technique and provides high shock absorption efficiency. In order to design the controller for the landing gear with MR damper, the equation of motion of the landing gear was derived. The hybrid controller was designed after constructing a simulation model using Recur-Dyne, multi-body dynamic analysis software. The hybrid controller can reduce the maximum strut force and displacement based on the skyhook controller, and is able to get the high efficiency by making it work for the additional force control technique. In addition, an effective switching control technique and input shaping technique was applied to prevent the chattering in the drop simulation. Finally, the performance of the landing characteristics was evaluated throughout the various drop simulations.

Internal Components Arrangement of MR Damper Landing Gear for Cavitation Prevention (캐비테이션 방지를 위한 MR 댐퍼형 착륙장치의 내부 형상 배치에 대한 연구)

  • Joe, Bang-Hyun;Jang, Dae-Sung;Hwang, Jai-Hyuk
    • Journal of Aerospace System Engineering
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    • v.14 no.5
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    • pp.33-41
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    • 2020
  • The landing gear of an aircraft is a device that absorbs and dissipates shock energy transmitted from the ground to the fuselage. Among the landing gears, the semi-active MR damper landing gear is supposed to show high-shock absorption efficiency under various landing conditions and secure the stability when out of control. In the case of the MR damper landing gear using an annular channel rather than orifice, Amesim, a commercial multi-physics program, is considered as more useful than the conventional two-degree-of-freedom model because the damping force generated by the pressure drop through the flow annular path can cause cavitation in the low-pressure chamber of the MR damper with a specific internal structure. In this paper, the main dynamic characteristics of the MR damper landing gear with an annular type flow path structure has been analyzed under the condition of cavitation. Based on the analysis results using Amesim, a design guideline for the MR damper flow path that prevents cavitation has been proposed based on the modification of the arrangement of internal components of the damper. The guideline was verified through a drop simulation.