• 한국융합학회논문지
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• 제11권1호
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• pp.195-200
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• 2020

본 연구에서는 쇽업소버 오리피스 유형별 유동해석을 하였다. 좋은 차의 기준에서 중요한 승차감을 위해서는 쇽업소버는 없어서는 안 될 존재이다. 해석 절차로서, 실제 쇽업소버의 실린더가 전진될 때의 속력을 유동 속도로 설정하여 쇽업소버의 모델 A, B, C들에 대한 유동 해석 결과들을 서로 비교하였다. 유동해석을 통해 각 모델의 오리피스 근처에서 유동흐름을 고찰하여 쇽업소버의 성능을 알아보았다. 전반적으로 모델 A가 유속이 가장 빨랐으며 유동변화 또한 가장 컸다. 모델 B가 유속이 가장 느렸으며 오리피스의 개수가 같은 모델 B, C의 유속 형상들은 비슷하였다. 본 연구를 통하여 어느 쇽업소버 오리피스 모델이 실린더 내에서의 유동을 원활히 하여 승차감을 상승시키는지를 알 수 있다. 쇽업소버 오리피스의 유형별 유동해석에 대한 본 해석 결과는 디자인 분야에 융합하여 적용될 수 있다고 보인다.

• 한국소음진동공학회논문집
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• 제20권5호
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• pp.444-452
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• 2010

This paper presents design and performance evaluation of electro-rheological(ER) shock absorber for electronic control suspension(ECS). In order to achieve this goal, a cylindrical ER shock absorber that satisfies design specifications for a mid-sized commercial passenger vehicle is designed and manufactured to construct ER suspension system for ECS. After experimentally evaluating dynamic characteristics of the manufactured ER shock absorber, the quarter-vehicle ER suspension system consisting of sprung mass, spring, tire and the ER shock absorber is constructed in order to investigate the ride comfort and driving stability. After deriving the equations of the motion for the proposed quarter-vehicle ER suspension system, the skyhook controller is implemented for the realization of quarter-vehicle ER suspension system. In order to present control performance of ER shock absorber for ECS, ride comfort and driving stability characteristics such as vertical acceleration and tire deflection are experimentally evaluated under various road conditions and presented in both time and frequency domain.

• 한국정밀공학회지
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• 제28권1호
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• pp.31-39
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• 2011

This paper presents design and control of a quarter-vehicle magneto-rheological (MR) suspension system for ECS (electronic control suspension). In order to achieve this goal, MR shock absorber is designed and manufactured based on the optimized damping force levels and mechanical dimensions required for a commercial mid-sized passenger vehicle. After experimentally evaluating dynamic characteristics of the manufactured MR shock absorber, the quarter-vehicle MR suspension system consisting of sprung mass, spring, tire and the MR shock absorber is constructed in order to investigate the ride comfort and driving stability. After deriving the equations of the motion for the proposed quarter-vehicle MR suspension system, the skyhook controller is then implemented for the realization of quarter-vehicle MR suspension system. In order to present control performance of MR shock absorber for ECS, ride comfort and driving stability characteristics such as vertical acceleration of sprung mass and tire deflection are experimentally evaluated under various road conditions and presented in both time and frequency domain.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 추계학술대회논문집
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• pp.375-380
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• 2007

This paper presents optimal design of controllable magnetorheological (MR) shock absorbers for passenger vehicle. In order to achieve this goal, two MR shock absorbers (one for front suspension; one for rear suspension) are designed using an optimization methodology based on design specifications for a commercial passenger vehicle. The optimization problem is to find optimal geometric dimensions of the magnetic circuits for the front and rear MR shock absorbers in order to improve the performance such as damping force as an objective function. The first order optimization method using commercial finite element method (FEM) software is adopted for the constrained optimization algorithm. After manufacturing the MR shock absorbers with optimally obtained design parameters, their field-dependent damping forces are experimentally evaluated and compared with those of conventional shock absorbers. In addition, vibration control performances of the full-vehicle installed with the proposed MR shock absorbers are evaluated under bump road condition and obstacle avoidance test.

• 한국소음진동공학회논문집
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• 제18권2호
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• pp.169-176
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• 2008

This paper presents optimal design of controllable magnetorheological(MR) shock absorbers for passenger vehicle. In order to achieve this goal, two MR shock absorbers (one for front suspension; one for rear suspension) are designed using an optimization methodology based on design specifications for a commercial passenger vehicle. The optimization problem is to find optimal geometric dimensions of the magnetic circuits for the front and rear MR shock absorbers in order to improve the performance such as damping force as an objective function. The first order optimization method using commercial finite element method(FEM) software is adopted for the constrained optimization algorithm. After manufacturing the MR shock absorbers with optimally obtained design parameters, their field-dependent damping forces are experimentally evaluated and compared with those of conventional shock absorbers. In addition, vibration control performances of the full-vehicle installed with the proposed MR shock absorbers are evaluated under bump road condition and obstacle avoidance test.

• 한국기계가공학회지
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• 제9권2호
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• pp.53-59
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• 2010

Stress analysis and fatigue life on shock absorber are investigated in this study. The lower part of spring is shown with the maximum equivalent stress and displacement of 153.49MPa and 26.151mm. The rear part is also shown with the number of fatigue life less than $6.8241{\times}10^5$. And the middle part of spring is shown with the minimum safety factor of 0.94592. The designed modeling suspension in this study has no possibility with resonance. As the result of this study is applied by the chassis of automobile, the prevention on fatigue fracture and the durability is predicted.

• 한국공작기계학회논문집
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• 제17권1호
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• pp.92-97
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• 2008

The safety and the durability of the shock absorber as an automotive chassis part under the fatigue load can be predicted in this study. The fatigue life becomes constant from 0.5 to 0.75 at the change of load which is the amplitude load divided by average load. But its life is sharply decreased at the change of load from 0.75 to 1.5. The influence of fatigue life according to the change of load can be predicted by these results. As the value of maximum damage is 9.61 at the middle part of upper side on shock absorber under the concentrated load, there is the greatest possibility of destruction at this part. The spring of shock absorber becomes nearly the state of pure shear and the uniaxial or biaxial stress exists at the rest part of it under the fatigue load.

• 한국자동차공학회논문집
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• 제6권4호
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• pp.1-8
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• 1998

In order to solve the conflict problem between the ride comfort and the road holding, the optimal design of shock absorber that minimizes the r.m.s. of sprung mass vertical acceleration and pitch rate with the understeer characteristics constraints in the high speed stability is proposed. The design of experiments and the nonlinear optimization algorithm are used together to obtain the optimal design of shock absorber. The second order regression models of the input variables(front and rear damping coefficients) and the output variables (ride comfort index and road holding one) are obtained by the central composite design in the design of experiments. Then the optimal design of shock absorber can be systematically adjusted with applying the nonlinear optimization algorithm to the obtained second order regression model. The frequency response analysis of sprung mass acceleration and pitch rate shows the effectiveness of the proposed optimal design of shock absorber in the sprung mass resonance range with the understeer characteristics constraints.

• 한국자동차공학회논문집
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• 제23권4호
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• pp.380-387
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• 2015

Various forms of passive shock absorber have developed to supplement performance which is poorer than that of active shock absorber. It is called 'Hybrid Conventional Damper (HCD)'. Frequency sensing shock absorber that this study will cover belongs to the HCD. This study aims to demonstrate that performance of frequency sensing shock absorber is superior than that of passive shock absorber. Study process is as follows. Firstly, analysis models for both passive shock absorber and frequency sensing shock absorber are developed to secure reliability. Then, elements which cause difference of ride quality are found out through comparison of hysteresis characteristics. By comparison of frequency characteristic, furthermore, damping principle of frequency sensing shock absorber is understood. Also, it determines if the absorber performs well even though maximum excitation speed is changed. Finally, the study proves that performance of frequency sensing shock absorber is superior than that of passive shock absorber after comparing change of damping power in excitation condition that various frequencies are mixed.

• 드라이브 ㆍ 컨트롤
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• 제16권1호
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• pp.7-13
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• 2019

The objective of this study was to present a damped pneumatic suspension, a bike fork suspension, which can adapt itself to incoming road excitations is presented in this paper. It consists of a hydraulic damper and a pneumatic spring in parallel with a linear spring. The study also proposed a variable and switchable orifice, in the hydraulic damper, to select appropriate damping property. Hydraulic-pneumatic circuit model for the bike fork suspension was established based on AMESim, in order to predict its performance. In addition, elastic-damping characteristics of the fork such as spring constant and viscous damping coefficient were computed and compared, for validation, with those evaluated by experiment using the universal test machine. Through simulation analysis and test, it was established that the hydraulic-pneumatic circuit model is effective and practical for development of future MTB suspensions.