• Title/Summary/Keyword: 시스템역학

Search Result 1,454, Processing Time 0.032 seconds

Requirement Analysis and Drag Prediction for the Aerodynamic Configuration of a Bearingless Rotor Hub (무베어링 로터 허브 형상에 대한 요구도 분석 및 항력 예측)

  • Kang, Hee-Jung
    • Aerospace Engineering and Technology
    • /
    • v.11 no.1
    • /
    • pp.19-26
    • /
    • 2012
  • The requirement for the aerodynamic hub drag, allocated from the system requirement of development of a bearingless rotor hub, was analyzed and embodied to be substantiated by the methodology assigned from the requirement. Drag prediction for the initial hub configuration was carried out by hand calculation using aerodynamic drag coefficients and the design change about the sectional shape of torque tube was suggested to satisfy the requirement. Finally, drag prediction was performed for the changed hub configuration by using unstructured overset mesh technique and parallel computation and the calculated result satisfied the requirement of the aerodynamic hub drag. It was found that the drag of final hub configuration was also within the range of drag inferred from the trendline of developed helicopter.

Calculation of the Dynamic Contact Force between a Shipbuilding Block and Wire Ropes of a Goliath Crane for the Optimal Lug Arrangement (최적 러그 배치를 위한 골리앗 크레인의 와이어 로프와 선체 블록간의 동적 접촉력 계산)

  • Ku, Nam-Kug;Roh, Myung-Il;Cha, Ju-Hwan
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.25 no.5
    • /
    • pp.375-380
    • /
    • 2012
  • In this study, dynamic load and dynamic contact force between a building block and wire ropes of a goliath crane are calculated during lifting or turn-over of a building block for the design of an optimal lug arrangement system. In addition, a multibody dynamics kernel for implementing the system were developed. In the multibody dynamics kernel, the equations of motion are constructed using recursive formulation. To evaluate the applicability of the developed kernels, the interferences and dynamic contact force between the building block and wire ropes were calculated and then the hull structural analysis for the block was performed using the calculation result.

Waveform Relaxation Method for Reactor Transient Analysis (원자로 천이해석을 위한 파형완화법)

  • Park, Keon-Woo;Co, Nam-Zin
    • Nuclear Engineering and Technology
    • /
    • v.27 no.6
    • /
    • pp.845-852
    • /
    • 1995
  • We investigate the concurrent solution of differential equations by the waveform relaxation (WR) method, an iterative method for analyzing linear and nonlinear dynamical systems in the time do-main. The method, at each iteration, decomposes the dynamical system into several subsystems, each of which is analyzed for the entire given time interval. The method, when efficiently implemented, results in algorithms with a highly parallelizable concurrent fraction. In this paper, the waveform relaxation method is introduced and applied to two types of reactor dynamics problems. It is concluded that the U method can be applied to reactor dynamics equations, but that its parallel performance on the KMRR dynamics is only modest.

  • PDF

A Characteristic Study of Compression Index(Cc) of the Deep Seabed Soft-Clay (대심도 해저 연약점토의 압축지수(Cc) 특성에 관한 연구)

  • Hong, Soon-Taek;Lee, Seung-Ho
    • Journal of the Korean GEO-environmental Society
    • /
    • v.12 no.5
    • /
    • pp.21-28
    • /
    • 2011
  • It is important to obtain detailed physical and mechanical properties of the soil for effective and economical plans and constructions of the structures located on deep seabed soft clay layer. This study is to find out the engineering properties of the seabed soft clay such as water content, initial void ratio, liquid and plastic limits, the compression index, etc., to make correlations between soil parameters, and to compare and analyze the findings with that from the previous researchers. Finally a representative correlation among the soil parameters was determined.

Usefulness of Meyerhold's 'Biomechanics' as an Alternative for a Method of Actor Training II - Focused on the Actual Training Program of 'Biomechanics' (배우 훈련 방법의 대안으로서 메이어홀드 '인체역학'의 효용성 II - '인체역학'의 실제 훈련 프로그램을 중심으로)

  • Cho, Han-Jun
    • The Journal of the Korea Contents Association
    • /
    • v.14 no.11
    • /
    • pp.89-101
    • /
    • 2014
  • The 'Biomechanics', which was devised to systematically train actor's material and medium, is evaluated as the first approach to an acting method in earnest with Stanislavsky's 'System'. Especially, due to the psycho-physical features of 'Biomechanics' that helps an actor to master a mechanism of human being such as stimulus, impulse and reaction, it was valued as an alternative for a naturalistic acting method that was excessively focused on the actor's emotional expression. However, the 'Biomechanics' is not utilized with activity in a field of actor training in Korea compared with Stanislavsky's 'The Method of Physical Action' which has a similar starting point as the psycho-physical feature. It is because of a political reason that a study for Meyerhold was officially forbidden in Russia until the mid-twentieth century. It is also because of a limit that incorporeal features of the 'Biomechanics' could not but be explained only by publications, especially translation. In this sense, as part of seeking for a new alternative of acting methods in Korea, this study will explore a possibility of applying the 'Biomechanics' to the actual actor training field through correct understanding of it.

Experimental Study on Frictional Healing Behavior of Rock Joints in the Natural Barriers under Hydro-Mechanical Conditions (천연방벽 내 암반 절리의 수리-역학적 조건에서의 마찰회복 거동에 대한 실험적 연구)

  • Yong-Ki Lee;Seungbeom Choi;Kyung-Woo Park;Jin-Seop Kim;Taehyun Kim
    • Tunnel and Underground Space
    • /
    • v.33 no.1
    • /
    • pp.42-56
    • /
    • 2023
  • In deep geological disposal of high-level radioactive waste (HLW), the natural barrier must physically support the disposal facility and delay the movement of radionuclides for at least hundreds of thousands of years. To evaluate the long-term geological evolution of the natural barriers, it is essential to analyze the long-term behavior of rock joints, including the frictional healing behavior. This study aimed to experimentally analyze the frictional healing behavior of rock joints under hydro-mechanical (H-M) conditions through the slide-hold-slide (SHS) test. The SHS tests were performed under mechanical and H-M conditions for joint specimens of different roughness. In the H-M conditions, the frictional healing rate tended to increase, which was more evident in the specimens with large roughness. In addition, it was confirmed that the effect of the hydro-mechanical conditions was more significant when the effective normal stress acting on the joint surface was small. These results are expected to be used as fundamental data to understand the frictional healing behavior of rock joints in the natural barriers.

다물체동역학 시스템의 불확실성 분석 및 설계

  • Yu, Hong-Hui
    • Journal of the KSME
    • /
    • v.54 no.2
    • /
    • pp.41-45
    • /
    • 2014
  • 이 글에서는 조인트, 부싱, 댐퍼 그리고 구동기 등으로 연결된 일반적 다물체계의 질량, 강성, 감쇠, 기하학적 제원 등에 존재하는 불확실성의 영향을 동적 해석 및 설계 시 어떻게 체계적으로 고려해야 하는지 대표적인 방법을 중심으로 관련 내용을 소개하고자 한다.

  • PDF