• Title/Summary/Keyword: Multi-body dynamic analysis

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Design of Excavator Boom Structure Based on Fatigue Strength of Weldment(II) (용접부 피로강도를 고려한 굴삭기 붐 구조물 설계(II))

  • Park, Sang-Chul
    • Journal of Welding and Joining
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    • v.29 no.4
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    • pp.61-66
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    • 2011
  • The purpose of this study is to develop improved boom structures with reliable fatigue strength of weldment and lower production cost. For that purpose, multi-body dynamic analysis was performed to evaluate forces acting on arm & boom cylinders and joints of boom structure during operation of an excavator for three working postures, then stress analysis was made to investigate stress distribution around diaphragms at the bottom plate of boom structures which was known to be susceptible to fatigue failures of welded joints, and finally boom structures with optimum arrangement of diaphragms was proposed. This work mainly consists of the following two parts: part 1 focuses on multi-body dynamic analysis of excavators during operation and part 2 includes evaluations of fatigue strength of welded joints for modified boom structures.

Dynamic Analysis of Floating Bodies Considering Multi-body Interaction Effect (다물체 연성효과를 고려한 부유체의 동적거동 안전성 해석)

  • Kim, Young-Bok;Kim, Moo-Hyun;Kim, Yong-Yook
    • Journal of the Society of Naval Architects of Korea
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    • v.46 no.6
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    • pp.659-666
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    • 2009
  • Recently, there are several problems in space, contiguity and facility of the existing harbors issued due to the trend of enlarging the container capacity of the large container vessel, the Mobile Harbor has been proposed conceptually as an effective solution for those problems. This concept is a kind of transfer loader of the containers from the large container ship, which is a floating barge with a catamaran type in the underwater part, and so prompt maneuverability and work effectiveness. For the safe mooring of two floating bodies, a container and the mobile harbor, in the near sea apart from the quay, a robot arm mooring facility specially devised would be designed and verified through comparison study under various environmental sea condition in the inner and outer harbor. DP system (Dynamic Positioning System) using the azimuth thruster and a pneumatic fender, etc, will be considered as a next research topic for the mooring security of multi-body floaters.

Dynamic Analysis of Timing Silent Chain System for a V-type Engine of a Vehicle

  • Feng, Zengming;Tang, Lechao;Li, Jun;Jia, Yanhui
    • Transactions of the KSME C: Technology and Education
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    • v.3 no.2
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    • pp.89-96
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    • 2015
  • Based on multi-body dynamic software RecurDyn, this paper proposes a modified form of timing silent chain system combing with the existing problem that vibration and chain tension is too large, which is applied for complicated conditions in a V-type engine, such as high speed, variable loads. The analysis of chain drive meshing characteristics is completed. Using the multi-body dynamic soft-ware RecurDyn, the dynamics characteristics of the improved system is studied, including chain tension, transmission error, chain fluctuations, equivalent spring force in different operating conditions. The study results show that chain tension, transmission error, chain fluctuation and equivalent spring force are within the scope of permission, all of them can meet the design requirement. There-fore, the design of this system is reasonable and practicable. The research results will provide a basis for assessing timing silent chain system in a V-type engine and a theoretical reference for designing and optimizing the timing silent chain system.

Development of Aerodynamic Analysis Technology for Wind Turbines using a Multibody Dynamic Analysis Software (다물체 동력학 해석 프로그램을 이용한 풍력발전기 공력해석 기술개발)

  • Rim, Chae Whan;Bang, Je Sung;Cho, Huije;Moon, Seok Jun;Chung, Tae Young
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.06a
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    • pp.180.2-180.2
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    • 2010
  • Simulation technology for dynamic analysis of wind turbine is developed. The Aerodyn and the DAFUL are chosen for aerodynamic analysis and multi-body and flexible body dynamics respectively. Subroutines and variables of Aerodyn developed by NREL are analyzed with hub-height wind data, full field turbulent wind data and Airfoil data. The interface to perform coupled analysis between AeroDyn and DAFUL, GUI for modeling several parts of wind turbines are developed. The program will be extended to analyze the coupled analysis of aerodynamic and hydrodynamic behavior for floating offshore wind turbines.

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Multi-body Dynamic Structural Dynamic Analysis of a Canopy System for Supersonic Fighter Considering Backup Emergency Egress Conditions (대체 비상탈출 조건을 고려한 초음속 전투기용 캐노피 작동부 구조해석)

  • Kim, Dong-Hyun;Kim, Dong-Man;Kim, Young-Woo;Yang, Jian-Ming
    • Journal of the Korea Institute of Military Science and Technology
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    • v.10 no.4
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    • pp.81-87
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    • 2007
  • In this study, analysis of structural design criteria for the canopy actuating device has been conducted considering the aerodynamic breakaway capabilities of jettisonable canopy system. Unsteady aerodynamic loads for the opened canopy configuration at passively controlled jettision mode were computed using CFD method. The general purpose multi-body finite element code, SAMCEF Mecano, is used in the implemented analyses for the passive jettision condition. The recommended altitude and speed of aircraft was suggested as design criteria of aerodynamic breakaway capability of jettisonable canopy system as a bakup egress method when normal canopy jettison sequence malfunctioned. Aerodynamic breakaway condition of jettisonable canopy was also simulated and the fracture load conditions of canopy actuator were investigated.

Biomechanical Analysis and Evaluation Technology Using Human Multi-Body Dynamic Model (인체 다물체 동역학 모델을 이용한 생체역학 분석 및 평가 기술)

  • Kim, Yoon-Hyuk;Shin, June-Ho;Khurelbaatar, Tsolmonbaatar
    • Journal of the Korean Society for Nondestructive Testing
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    • v.31 no.5
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    • pp.494-499
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    • 2011
  • This paper presents the biomechanical analysis and evaluation technology of musculoskeletal system by multi-body human dynamic model and 3-D motion capture data. First, medical image based geometric model and material properties of tissue were used to develop the human dynamic model and 3-D motion capture data based motion analysis techniques were develop to quantify the in-vivo joint kinematics, joint moment, joint force, and muscle force. Walking and push-up motion was investigated using the developed model. The present model and technologies would be useful to apply the biomechanical analysis and evaluation of human activities.

Study on the Effects of System Parameters on the High Cycle Fatigue Life Based on Structural Dynamic Analysis of a Turbine Blade System (터빈 블레이드의 구조동역학해석에 근거한 시스템 인자들의 고사이클 피로수명에 대한 영향도분석)

  • Kwon, Sung-Hun;Song, Pil-Gon;Park, Jong-Hyun;Yoo, Hong-Hee
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.875-879
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    • 2007
  • The effects of the statistical properties of the Coulomb friction coefficients on the dynamic responses of a galloping quadruped robot are investigated in this paper. In general, the Coulomb friction coefficients are assumed to be deterministic for a controller design to achieve required motion characteristics. However, the friction coefficients between the ground and the robot legs are not constant in reality. Therefore, statistical characteristics of the friction coefficients need to be considered for a multi-body modeling of the robot galloping on the ground. The effects of the statistical properties on the dynamic responses of the quadruped robots are investigated.

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Efficient Super-element Structural Vibration Analyses of a Large Wind-turbine Rotor Blade Considering Rotational and Aerodynamic Load Effects (회전 및 풍하중 가진 효과를 고려한 대형 풍력발전 로터의 효율적인 슈퍼요소 구조진동해석)

  • Kim, Dong-Man;Kim, Dong-Hyun;Park, Kang-Kyun;Kim, Yu-Sung
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.19 no.7
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    • pp.651-658
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    • 2009
  • In this study, computer applied engineering(CAE) techniques are fully used to efficiently conduct structural and dynamic analyses of a huge composite rotor blade using super-element. Computational fluid dynamics(CFD) is used to predict aerodynamic loads of the rotating wind-turbine blade. Structural vibration analysis is conducted based on the non-linear finite element method for composite laminates and multi-body dynamic simulation tools. Various numerical results are presented for comparison and the structural dynamic behaviors of the rotor blade are investigated herein.

Multi-Body Dynamics Characteristics of Variable Nozzle (가변노즐의 다물체동력학적 특성)

  • Park, Dong-Chang;Lee, Sang-Youn;Yun, Su-Jin;Yoon, Hyun-Gull
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.711-712
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    • 2010
  • In the present work, the dynamic characteristics of variable nozzles are described. Variable nozzles are used to enhance the effectiveness of aircraft engines at various altitudes. The dynamic characteristics of variable nozzle mechanism including flaps are analyzed by a multi-body dynamics analysis software, RecurDyn.

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Structural Dynamics Analyses of a 5MW Floating Offshore Wind-Turbine Using Equivalent Modeling Technique (등가모델링기법을 이용한 5MW급 부유식 해상용 풍력발전기 구조동역학해석)

  • Kim, Myung-Hwan;Kim, Dong-Hyun;Kim, Dong-Hwan;Kim, Bong-Yung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2011.10a
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    • pp.614-622
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    • 2011
  • In this study, the computational structural dynamic modeling of floating offshore wind turbine system is presented using efficient equivalent modeling technique. Structural dynamic behaviors of the offshore floating platform with 5MW wind turbine system have been analyzed using computational multi-body dynamics based on the finite element method. The considered platform configuration of the present offshore wind turbine model is the typical spar-buoy type. Equivalent stiffness and damping properties of the floating platform were extracted from the results of the baseline model. Dynamic responses for the floating wind turbine models are presented and compared to investigate its structural dynamic characteristics. It is important shown that the results of the present equivalent modeling technique show good and reasonable agreements with those by the fully coupled analysis considering complex floating body dynamics.

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