• 제목/요약/키워드: initial deflection

검색결과 252건 처리시간 0.029초

The Vibration Control of Flexible Manipulator using A Reference Trajectory Command and Fuzzy Controller

  • Park, Yang-Su;Kang, Jeng-Ho;Park, Yoon-Myung;Cho, Yong-Gab
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2001년도 ICCAS
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    • pp.67.3-67
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    • 2001
  • A fuzzy control strategy is described which is utilized to control the joint angle and tip deflection in single flexible manipulator. In this paper, an existing model for a single flexible manipulator is used f3r the initial development of an FLC. One FLC is designed to govern the joint angle of the manipulator as it is rotated from one position to another, and a second FLC is designed to attenuate the tip deflection which result from joint angle body motion. Reference Trajectory Command is an important method to reduce vibration in flexible beam. This paper presents a very simple command control shaping which eliminates multiple mode residual vibration in a flexible beam combined fuzzy controller ...

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사장교의 내진설계를 위한 동적해석에 관한 연구 (A Study on Dynaniic Analysis for Earthquake Design of cable-stayed Bridges)

  • 이진휴;이재영;이장춘
    • 한국농공학회지
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    • 제36권1호
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    • pp.103-115
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    • 1994
  • The dynamic earthquake analysis of plane cable-stayed bridge structures was formulated and implemented into a computer program which analyzes plane cable-stayed bridge structu- res subjected to initial cable tensions, member dead and live loads and seismic loads. Cable-stayed bridges were modelled as multi-degrees of freedom systems with lumped- mass. Various earthquake responses such as dynamic deflection, bending moment, shear force and cable tension were investigated by the dynamic analyses in the form of the time history analysis. The time history analysis was based on the mode superposition method. The study revealed that Fan-l type cable-syayed bridges is generally superior to other types for the earthquake proof even though aspects of deflection and section force of each type presents respective advantages and disadvantages. The study provided a method to design the sections of cable-stayed bridges under seismic loads with various design parameters related to structural types. The study is expected to be useful for effective design of cable-stayed bridges with conside- ration of earthquake.

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호장증분법에 의한 선체판의 처짐모드에 관한 연구 (A Study on the Deflection Mode of a Ship's Plate according to the Arc-Length Method)

  • 고재용;박주신;이돈출;박성현
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 춘계학술대회논문집
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    • pp.732-737
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    • 2003
  • Recently, the buckling is easy to happen a thin plate and High Tensile Steel is used at the structure so that it is wide. Especially, the buckling is becoming important design criteria in the ship structure to use especially the High Tensile Steel. Consequently, it is important that we grasp the conduct after the buckling behaviour accurately at the stability of the body of ship structure. In this study, examined closely about conduct and secondary buckling after initial buckling of thin plate structure which receive compressive load according to various kinds aspect ratio under simply supported condition that make by buckling formula in each payment in advance rule to place which is representative construction of hull. Analysis method is F.E.M by ANSYS and complicated nonlinear behaviour to analyze such as secondary buckling.

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매시브콘크리트에 배근된 주철근의 부착특성에 관한 해석적 연구 (An Analytical Study on the Bond-Properties of Axial Bars Embedded in Massive Concrete)

  • 장일영;이호범;이승훈;변근주
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 1992년도 봄 학술발표회 논문집
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    • pp.143-147
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    • 1992
  • Description of the behavior of the R.C structural members fixed on massive concrete is not normally generalization of recognized configuration for regular R.C. design guidanes. This can be due to the complexity of evaluation of internal resistancy and deflection changes of the members subjected to the various external forces. On the base of axially loaded member fixed on footing, however, the estimation of deflection changes due to flexural force shear force and rotational force is to be carried out in ways of specifying the bond characteristics of axial bars embedded in massive concrete. This work is to quantify adhesion of steel-concrete, initial concrete cracking stress near bar rib, maximum bond stress and residual stress in concrete respectively. In addition to quantification of them for particulate behavior, the suggestions of multi-linear bond stress-slip diagram made in carrying out finite element analyses for adhesion failure, examining concrete cracking status and reviewing existing experimental data lead to alternatively constructed relationship between bond stress and slip for a axial bars embedded massive concrete.

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STUDY ON RIDE QUALITY OF A HEAVY-DUTY OFF-ROAD VEHICLE WITH A NONLINEAR HYDROPNEUMATIC SPRING

  • SUN T.;YU F.
    • International Journal of Automotive Technology
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    • 제6권5호
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    • pp.483-489
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    • 2005
  • Based on a two-degree of freedom vehicle model, this paper investigates ride comfort for a heavy off-road vehicle mounted a nonlinear hydropneumatic spring, which is influenced by nonlinear stiffness and damping characteristics of the hydropneumatic spring. Especially, the damping force is derived by applying H. Blasius formula in modeling process according to the real physical structure of the hydropneumatic spring, and the established model of nonlinear stiffness characteristics have been validated by experiments. Furthermore, the effects of parameter variations of the hydropneumatic spring, such as initial charge pressure and damping coefficient, on body acceleration, suspension deflection and dynamic tire deflection are also investigated.

전단지간비에 따른 철근콘크리트 보의 전단강도특성에 관한 연구 (A Study on the Shear Strength Properties of Reinforced Concrete Beams according to Shear Span-Depth Ratio)

  • 박종건
    • 한국구조물진단유지관리공학회 논문집
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    • 제4권1호
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    • pp.93-100
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    • 2000
  • The purpose of this study is to investigate the shear behavior of reinforced concrete beams according to small shear span-depth ratio between a/d=1.5, 2.8, 3.6. In general, shear strength of reinforced concrete beams is dependent on the compressive strength of concrete the longitudinal steel ratio, the shear span-depth ratio and shear reinforcement. The static test was carried out to measure the ultimate load, the initial load of flexural and diagonal cracking, crack patterns, fracture modes. The load versus strain and load versus deflection relations were obtained from the static test. The test results on shear strength were compared with results obtained by the formulas of ACI code 318-95. The shear strength of reinforced concrete beams exceeded those predicted following present ACI code 318-95(11-6).

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차량 탑재형 안테나 포지셔너의 반사판 지지대 최적설계 (Design Optimization of the Support Frame of an Antenna Positioner Mounted on a Vehicle)

  • 장태호;김영식
    • 한국정밀공학회지
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    • 제31권5호
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    • pp.411-416
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    • 2014
  • In this research we present design optimization methods for a vehicle-mounted satellite antenna positioner. Our initial antenna positioner was conservatively designed to satisfy a worst case scenario where wind blew across the positioner at the speed of 120 km/h. Investigating stresses and safety based on Finite Element Methods (FEM), we find reflector support frames can be optimized to significantly reduce the weight of the positioner system. Thus, we optimize the reflector support frame from the given initial design while considering weight, maximum stress, maximum allowable deflection, cross section, and thickness. As a result, Shape C and the thickness of 2 mm are determined for the cross section of the reflector support frame. Applying this result, the weight of the new antenna positioner is 57.343 kg, which is decreased by 10.74% compared to the initial conservative design.

Ultimate torsional strength of cracked stiffened box girders with a large deck opening

  • Ao, Lei;Wang, De-Yu
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제8권4호
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    • pp.360-374
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    • 2016
  • The present paper studies the ultimate torsional strength of stiffened box girders with large deck opening due to the influence of cracks. Three types of hull girders with different spans are provided for comparison. Potential parameters which may have effects on the torsional strength including the mesh refinement, initial deflection, material strain hardening, geometric properties of crack and stiffener are discussed. Two new concepts that play an significant role in the ultimate strength research of damaged box girders are introduced, one of which is the effective residual section (ERS), the other is the initial damage of the failure zone (IDFZ) for intact structures. New simple formulas for predicting the residual ultimate torsional strength of cracked stiffened box girders are derived on the basis of the two new concepts.

준등방성 복합적층판의 저속충격에 의한 손상특성 (Damage Characteristics of Quasi Isotropic Composite Laminates Subjected to Low Velocity Impact)

  • 김재훈;전제춘
    • 한국정밀공학회지
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    • 제14권6호
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    • pp.135-141
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    • 1997
  • Low velocity impact test and compressive residual strength test after impact were performed by using Hercules AS4/3501-6[45/0/-45/90]$_{2s}$ laminated plate to investigate the low velocity impact damage behavior and the post-impact strength degradation on orthotropic composite laminate plate. Due to the lateral impact losd, the load path showed "" shape according to the laminate central deflection. Damage in a laminate occurs by inclined matrix crack at the damage initiation load stage and vertical matrix crack, occurs on the outer surface. Evaluating the compressive residual strength after the low velocty impact test, it could be found that there is a transient range where the compressive residual strength drop suddenly in the initial damage which is in the matrix crack range and the initial delamination area. is in the matrix crack range and the initial delamination area.

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오일부 운전조건 변화에 따른 수소용 다이어프램 압축기의 성능예측에 대한 수치해석 (A Numerical Analysis on a Dependence of Hydrogen Diaphragm Compressor Performance on Hydraulic Oil Conditions)

  • 박현우;신영일;이영준;송주헌;장영준;전충환
    • 한국수소및신에너지학회논문집
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    • 제20권6호
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    • pp.471-478
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    • 2009
  • The specific some types of compressors are appropriate for a use in hydrogen gas station. Metal diaphragm type of hydrogen compressor is one of them, which can satisfy the critical requirements of maintaining gas purity and producing high pressure over 850 bar. The objective of this study is to investigate an characteristics of compression through two-way Fluid-Structure-Interaction (FSI) analysis as bulk modulus and initial volume of oil independently varies. Deflection of diaphragm, oil density, gas and oil pressure were analyzed during a certain period of compression process. According to the analysis results, bulk modulus and initial volume remarkably affected deflection of diaphragm, oil density, gas and oil pressure. The highest gas pressure were attained with the highest bulk modulus of $7e^9\;N/m^2$ and the lowest initial oil volume of 80 cc.