• Title/Summary/Keyword: 전륜

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Development of Nitrogen Charging Trailer for Aircraft Improved Operability (운용성을 개선한 항공기용 질소충전트레일러 국산화 개발)

  • Park, Hyo-Jin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.6
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    • pp.513-518
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    • 2018
  • Nitrogen charging trailer applied to KUH-1 is a device to charge Nitrogen in main front wheel buffer, tail bumper buffer, brake accumulator and tire of aircraft. As the name suggests, it is a device that has mobility along with nitrogen charging. Originally supplied by Tronair in the United States, it was imported from Korea, and the locally developed product not only satisfies the performance of the existing product, but also designed to be easier than the product introduced in the operation. It was selected as the joint investment project of the 15th civilian government building, and development needs analysis and test evaluation were carried out under the support of development and management of Korea Aerospace Industries and Defense Agency for Technology and Quality.

An Evaluation on the Steering Stability of the Guideway Vehicle (안내궤도 차량의 조향 안정성 평가)

  • 윤성호
    • Transactions of the Korean Society of Automotive Engineers
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    • v.10 no.1
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    • pp.209-215
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    • 2002
  • A study of the guideway vehicle was made for a comparison of ride stabilities between its two primary steering types; one is the front wheel steering and the other the front-rear wheel. A numerical model as a closed loop system was built for an investigation of various factors to have an influence on the vehicular critical speed which is closely associated with ridabilities. It was shown that dynamics stabilities of the front steering type was much better over a large value of steering gain and the longer distance between front axle and guide link for both types provided better stabilities as well. A large steering gain ratio of the front to the rear significantly plays an important role in an improvement of stability in the front-rear steering. To observe a qualitative trend on stability behaviors, the root locus was obtained by considering a time lag which may be frequently caused by the complicated steering mechanism. In performing so, the appropriate selection of steering gain had a greater effect on the front-rear steering vehicle far more ride comfort. In addition, the dynamics model proposed here can be utilized for a more accurate evaluation on the vehicle design in lateral or yawing absorber and moreover expanded for the analysis of independent four-wheel steering vehicle.

The Optimum Design of Rotor Shape in Front Disk Brake System for Squeal Noise Reduction using the DOE (실험계획법을 이용한 전륜 디스크 브레이크 시스템의 로터형상 스퀼소음 저감 최적화)

  • Lee, Hyun-Young;Joe, Yong-Goo;Abu, Aminudin Bin;Lee, Jung-Youn;Oh, Jae-Eung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.236-240
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    • 2005
  • This paper deals with friction-induced vibration of disc brake system under constact friction coefficient. A linear, finite element model to represent the floating caliper disc brake system is proposed. The complex eigenvalues are used to investigate the dynamic stability and in order to verify simulations which are based on the FEM model, The comparison of experimental and analytical results shows a good agreement and the analysis indicates that mode coupling due to friction force and geometric instability is responsible fur disc brake squeal. And the Front brake system reduced the squeal noise using design of experiment method(DOE). This helped to validate the FEM model and establish confidence in the simulation results. Also they may be useful during real disk brake model.

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Optimization of front Bump Steer for Improving Vehicle Handling Performances (차량의 조종 안정성 향상을 위한 전륜 범프 스터어 최적화)

  • 서권희;이윤기;박래석;박상서;윤희석
    • Journal of the Korean Society for Precision Engineering
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    • v.17 no.2
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    • pp.80-88
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    • 2000
  • This paper presents a method to optimize the bump steer characteristics (the change of toe angle with vertical wheel travel) with respect to hard points in the double wishbone front suspension of the four-wheel-drive vehicle using the design of experiment, multibody dynamics simulation, and optimum design program. Front and rear suspensions are modeled as the interconnection of rigid bodies by kinematic joints and force elements using DADS. The design variables with respect to the kinematic characteristics are obtained through the experimental design sensitivity analysis. An object function is defined as the area of absolute differences between the desired and experimental toe angle. By the design of experiment and regression analysis, the regression model function of bump steer characteristics is extracted. The design variables that make the toe angle optimized are selected using the optimum design program DOT. The lane change simulations and tests of the full vehicle models are implemented to evaluate the improvement of vehicle handling performances by the optimization of front bump steer characteristics. The results of the lane change simulations show that the vehicle with optimized bump steer has the weaker understeer tendency than the vehicle with initial bump steer.

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A Study on the Growth of Pacific Ocean Perch, Sebastes alutus Gilbert, in the Gulf of Alaska (알라스카만산 적어, Sebastes alutus Gilbert의 성장에 관한 연구)

  • ZHANG Chang Ik
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.14 no.3
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    • pp.171-178
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    • 1981
  • The growth of Sebastes alutus was studied by scale reading to check the change of growth rate at the early stage of life. Lee's phenomenon was recognized on the scale measurements except thc first ring radius. No evidence was found to support the change of growth rate at early stage. Von Bert-alanffy's growth equation was estimated with the back-calculated fork lengths, $1_t=357.8(1-e^{-0.6124(t+1.8566)}),\;and\;W_{\infty}=784.4g$

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A Study on the Non-Linear Static Analysis for L-type Front Lower Control Arm (L 형 전륜 로어 암의 대하중 강도 해석 기법 연구)

  • Lee, Soon-Wook;Koo, Ja-Suk;Song, Min-Soo
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.453-458
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    • 2008
  • Under driving condition, A vehicle experiences various kinds of loads, which brings on the buckling and fracture of suspension systems. Lower control arm (LCA), which consists of 2 bush joints and 1 ball joint connection, is the one of the most important parts in the suspension system. The bush joints absorb the impact load and reduce the vibration from the road. When analyzing the LCA behavior, it is important to understand the material properties and boundary conditions of bushing systems correctly, because of the nonlinearity characteristics of the rubber. In this paper, in order to predict the large scale deformation of the LCA more precisely, three factors are newly suggested, that is, coupling of bush stiffness between translation and rotation, bush extraction force and maximum rotation angle of ball joint. LCA stiffness is estimated by CAE and component test. Analysis and test results are almost same and the validity of considering three factors in LCA analysis is verified.

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Analysis of Durability of Vehicle Chassis Part in Virtual Test Lab (가상내구시험을 통한 차량 샤시 부품 내구성 예측에 관한 연구)

  • Cho, ByungKwan;Ha, Jungho
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.6
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    • pp.747-752
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    • 2013
  • Recently, virtual test laboratory techniques have been widely used to reduce vehicle development costs and time. In this study, a virtual durability test process using multibody dynamics simulation and fatigue simulation is proposed. The flexible multibody model of the front half of a car suspension is solved using road loads that are measured from durability test courses such as a Belgian road. To verify the simulation results, the measured loads of components and simulation results are collated.

Structural Design of a Front Lower Control Arm Considering Durability (내구성을 고려한 하부 컨트롤 암의 구조설계)

  • Park, Han-Seok;Kim, Jong-Kyu;Seo, Sun-Min;Lee, Kwon-Hee;Park, Young-Chul
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.8 no.4
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    • pp.69-75
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    • 2009
  • Recently developed automotive components are getting lighter providing a higher fuel efficiency and performance. Following the current trend, this study proposes a structural optimization method for the lower control arm installed at the front side of a Vehicle. Lightweight design of lower control arm can be achieved through design and material technology. In this research, the shape of lower control arm was determined by applying the optimization technology and aluminum was selected as a steel-substitute material. Strength performance is the most important design requirement in the structural design of a control arm. This study considers the static strength in the optimization process. For the optimum design, the durability analysis is performed to predict its fatigue life. In this study, the kriging interpolation method is adopted to obtain the minimum weight satisfying the strength constraint. Optimum designs are obtained by the in-house program, EXCEL-Kriging. Also, based on the optimum model obtained for the static strength, the optimization of Index of Fatigue Durability is carried out to get th optimum fatigue performance.

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An Optimal Design of the Front Wheel Drive Engine Mount System (전륜구동형 승용차의 엔진마운트 시스템 최적설계)

  • Kim, M.S.;Kim, H.S.;Choi, D.H.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.1 no.3
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    • pp.74-82
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    • 1993
  • Optimal designs of a 3-point and a 4-point engine mount system are presented for reducing the idle shake of a Front Wheel Drive(FWD) vehicle. Design variables used in this study are the locations, the angles and the stiffness of an engine mount system. The goal of the optimization is minimizing the transmitted force without violating the constraints such as static weight sag, resonant frequency and side limits of design variables. The Augmented Lagrange Multiplier(ALM) Method is used for solving the nonlinear constrained optimization. The generalized Jacobi and the impedence method are employed for a free vibration analysis and a forced response analysis. The trend of analysis results well meet that of the experimental results. The optimization results reveal that the 4-point system transmits less torque than the 3-point system. It is also found from the design sensitivity analysis that the vibration characteristics of the 4-point system is less sensitive than those of the 3-point system.

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Development of Vehicle Integrated Dynamics Control System with Brake System Control (제동 장치를 이용한 차량통합운동제어시스템 개발)

  • Song, Jeonghoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.7
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    • pp.591-597
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    • 2017
  • This study is to develop a vehicle Integrated Dynamics Control System(IDCB) that can stabilize the lateral dynamics and maintain steerability. To accomplish this task, an eight degree of freedom vehicle model and a nonlinear observer are designed. The IDCB independently controls the brake systems of four wheels with a fuzzy logic control and a sliding model control. The result shows that the nonlinear observer produced satisfactory results. IDCB tracked the reference yaw rate and reduced the body slip angle under all tested conditions. It indicates that the IDCB enhanced lateral stability and preserved steerability.