• Title/Summary/Keyword: 6-자유도

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선박의 무게중심 변화에 따른 안정성 해석에 관한 수치 시뮬레이션 - 세월호 침몰을 교훈으로 -

  • Park, Jong-Cheon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2014.06a
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    • pp.11-12
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    • 2014
  • 본 연구에서는 일정속도로 항행하는 선박의 후미에서 20도의 각도로 진행하는 뒤파도가 존재할 경우, 선박의 무게중심 변화에 따른 안정성 해석에 대해 전산유체역학(CFD) 기술을 이용하여 운동 시뮬레이션을 수행하였다.

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정보 - 2015년도 FTA 피해보전직불제

  • 대한양계협회
    • KOREAN POULTRY JOURNAL
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    • v.47 no.7
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    • pp.144-145
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    • 2015
  • 최근 정부는 "자유무역협정 체결에 따른 농어업인 등의 지원에 관한 특별법" 제6조에 따라 자유 무역협정의 이행으로 수입량이 급격히 증가하여 가격 하락의 피해를 입은 품목의 생산자에게 가격 하락의 일정 부분을 지원함으로써, 농업인 등의 경영안정을 도모하고 피해를 보전하기 위해 2015년도 FTA 피해보전직불제 사업시행지침을 발표했다. 세부 사항은 농림축산식품부 홈페이지(www.mafra.go.kr)를 통해 확인할 수 있다.

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Dynamic Analysis of the Engine-Resilient Mount System (엔진-탄성마운트 시스템의 동적특성해석)

  • 김영중;유광택
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1991.04a
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    • pp.119-125
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    • 1991
  • 본 연구에서는 일반적인 6자유도의 비대칭 강체가 3방향 탄성계수를 갖는 마운트에 지지되어 있는 6장도계의 진동해석기법을 확립하고, 고유진동, 강 제진동응답 및 진동전달력해석을 위한 프로그램을 개발하였다. 아울러 실제 응용된 사례와 타종의 마운트를 적용한 결과를 비교함으로써 설계의 타당성 을 검증하였다.

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Vibration Control of Composite Wing-Rotor System of Tiltrotor Aircraft (틸트로터 항공기 복합재료 날개의 진동 제어)

  • Song, Oh-Seop
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.35 no.6
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    • pp.509-516
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    • 2007
  • Mathematical modeling and vibration control of a tiltrotor aircraft composite wing-rotor system are investigated in this study. A wing-mounted rotor can be tilted from the vertical position to a horizontal one, and vice versa. Effect of vibration control of the wing-rotor system via piezoelectricity is studied as a function of tilt angle, ply angle of composite wing and rotor's spin speed. Composite wing is modeled as a thin-walled box beam having a circumferentially uniform stiffness configuration that produces elastic coupling between flap-lag and between extension-twist behavior. Numerical simulations are provided and pertinent conclusions are outlined.

Aerodynamic Simulation of Air-Launched Missiles from a Complete Helicopter (헬리콥터 전기체에서 발사되는 유도무기 공력 모사)

  • Lee, Hee-Dong;Kwon, Oh-Joon;Lee, Bum-Seok;Noh, Kyung-Ho
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.39 no.12
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    • pp.1097-1106
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    • 2011
  • Unsteady numerical analysis was performed to simulate air-launched missiles from a complete helicopter in hover by using an unstructured overset mesh flow solver coupled with a module of six degree-of-freedom motion of equations. The unsteady computations have been performed to obtain flow fields around the complete helicopter including main rotor, tail rotor, and fuselage equipped with multiple missiles, and six-DOF simulation has been performed to predict the behavior of the air-launched missile. The effects of the launching position and the missile thrust on the trajectory of the missile were investigated as well as the aerodynamic interference of the air-launched missile under the unsteady downwash produced by main rotor.

Design, Implementation, and Control of Two Arms of a Service Robot for Floor Tasks (바닥작업이 가능한 양팔 서비스 로봇의 기구학 설계, 제작 및 제어)

  • Bae, Yeong Geol;Jung, Seul
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.3
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    • pp.203-211
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    • 2013
  • This paper presents the implementation and control of two arms of an indoor service robot for floor tasks. The robot arms are designed to have 6 degrees-of-freedom (DOF), but actually built to have 5 DOF. Forward and inverse kinematics of two arms are analyzed and simulated to confirm the kinematic analysis. Two arms are actually controlled based on the inverse kinematics. The right and left arms are separately controlled to follow different trajectories in order to make sure the functionality of both arms. Experimental studies are conducted to confirm the kinematic analysis and proper operation of two arms.

Development of Meshless Method for Free Vibration Analysis of Arbitrarily Shaped Free Plates Using Local Polar Coordinates (지역 극좌표계를 이용한 임의 형상 자유단 평판의 자유진동해석을 위한 무요소법 개발)

  • Kang, Sang-Wook;Atluri, S. N.
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.6
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    • pp.674-680
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    • 2008
  • A new meshless method for obtaining natural frequencies of arbitrarily shaped plates with the free boundary condition is introduced in the paper. In order to improve the characteristics of convergence and accuracy of the method, a special local polar coordinates system is devised and located for each of nodes distributed along the boundary of the plate of interest. In addition, a new way of decreasing the size of the system matrix that gives natural frequencies of the plate is employed to reduce the amount of numerical calculations, which is needed for computing the determinant of the system matrix. Finally the excellence of the characteristics of convergence and accuracy of the method is shown in several case studies, which indicate that natural frequencies by the proposed method are very accurate and converged swiftly to exact values as the number of boundary nodes increases.

Development of Hydraulic Rock Splitting Technique for Rock Excavation (암반 굴착을 위한 수압암반절개 기술 개발)

  • Park, Jongoh;Lee, Dal-Heui
    • The Journal of Engineering Geology
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    • v.26 no.3
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    • pp.353-360
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    • 2016
  • Tests of hydraulic rock splitting were conducted using double packer at the 1, 2 free surface in the limestone mining and granodiorite Suksan area, respectively. The method of hydraulic rock splitting was applying hydraulic power in the interval layer using double packer. As a result of tests, a crack occurred. At about 6.5 MPa and 13 MPa, a crack occurred in 2 free surface. Any crack did not occur in the 1 free surface. Rather, used 1 double packer was broken in the 1 free surface. Also, it was confirmed that the water pressure of the interval increased through the existing crack and the new crack in the test areas.