• 한국소음진동공학회논문집
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• 제16권6호
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• pp.602-608
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• 2006

In order to evaluate performance of anti-vibration gloves, it is necessary to measure the transmitted vibration to the hand and the applied forces at the same time while gripping the vibrating handle. In the study a system was developed to measure both the vibration and the forces. The system consists of a measurement handle with eight strain gauges and two accelerometers and a PC-based system with a software for signal processing and evaluation of the hand-transmitted vibration and for control of applied forces in the pre-determined range. The handle was installed on the vibration shaker which is strong enough so as not to be affected by dynamic coupling with the hand-arm system. Whole procedure of ISO 10819 to determine the vibration transmissibility of anti-vibration gloves was programmed into the system. As an example of the application, three subjects joined the test to get vibration transmissibilities of anti-vibration gloves where each glove was tested twice a subject. Average and standard deviation of vibration transmissibility were also calculated.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 2003년도 추계학술대회 논문집
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• pp.1311-1318
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• 2003

최근 흡한 속건성은 사이언스 소재로 가장 보편적으로 이용되고 있는 소재 성능이다. 하지만 아직 제대로 된 측정 평가법이 존재하고 있지 않고, 몇몇 의류업체에서는 단순히 객관적 속성만을 측정하고 있다. 본 연구에서는 객관적 속성인지들의 연속적이 값들이 실제 인체에서는 얼마만큼의 변별력으로 인식되는지 정신물리학적 측정법으로 최소 자극치(PSE)를 구하여 등급을 나누어 보았다. 시료는 흡한속건성 직물로 가장 많이 이용되고 있는 Coolmax(R), Coolever(R), 친수성 이중직물의 3개 그룹으로 나누었고, 측정 인자로 객관적 속성인자는 cling force, drying time을, 이와 대응하는 주관적 속성인자는 clinginess, dampness를 측정하고 각각의 PSE값을 구하였다. 그룹에 따라 객관적 속성인자 값들이 이라고 느끼는 PSE 구간까지 도달하는 시간과 속력을 측정하여 그룹마다의 흡한속건 등급을 정하였다. 또한 설계된 소재의 성능을 간접적으로 알 수 있는 transmissibility라는 인자도 도입하여 수분 전달성도 객관적으로 살펴볼 수 있었다. Clinginess, Dampness, Transmissibility 각 인자들을 평가해본 결과 Coolmax(R) 가 가장 우수함을 알 수 있었다.

• Journal of Biosystems Engineering
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• 제35권3호
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• pp.182-188
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• 2010

Post-Harvest processing engineering is a field that studies prevention of the quality change of agricultural products during sorting, packaging, storage, and distribution after harvested. In distribution steps, agricultural products could be damaged by physical force, it is the main reason of low quality and they lost value of commodities. This study was performed to find the vibration characteristics of the peach, and to find the extent of the damage on the peach by fatigue stress. The vibration data was obtained on expressway and the vibration characteristics of peach was used to find the damage on the peach. To analyze the vibration characteristics of peach, the resonance frequency and vibration transmissibility were measured. The resonance frequency of the peach was 167.98 Hz and the transmissibility was 4.06 at resonance point. It was 150 ~ 250 Hz that the transmissibility was more than 1. And the transmissibility in simulated test was measured. When the trasmissibility was more than 1, the range was 15 ~ 65 Hz, and when it was less than 1, the range was 65 ~ 175 Hz. When the transmissibility was about 1, the range was 5 ~ 15 Hz. The damage and the vibration cycle numbers of peaches were compared with input frequency and acceleration. More damage and less cycle number happened in 30 Hz than in 62.5 Hz. The reason was that the transmissibility of 30 Hz was higher and the vibration displacement in lower frequency was more. The more acceleration and cycle number increased, the more the bruising volume of peaches increased. The bruising volume ratio for vibration fatigue was measured according to input acceleration and cycle number. Using measured data, regression models for bruising volume ratio(BVR) was developed as a function of the acceleration(A) and cycle number(CN) as follows. BVR = a * $A^b*$ $(CN)^c$

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2011년도 춘계학술대회 논문집
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• pp.409-414
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• 2011

The drivers of commercial vehicle easily feel tired because of a long time driving and bad road condition. Therefore it is very important to make the driver seat comfortable. This paper introduces the suspension system of driver's seat using magnetic force. The combination of linear spring and magnetic force can make nonlinear spring which has optimal stiffness for minimal vibration transmissibility. The vibrations of driver's seat floor are measured in various road condition. And the numerical simulations and experiments are performed to define the optimal parameter of magnetic suspension system.

• 한국정밀공학회지
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• 제15권10호
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• pp.58-64
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• 1998

Rubber isolator has many advantages compared with steel spring mount. Rubber has high internal damping and can be formed various shape depending on specific purpose. On the contrary, low modulus of elasticity of rubber results the instability of rubber isolator by buckling phenomenon. This paper presents the development of shear type rubber isolator for industrial application by using shear rigidity property of rubber. The static load-deflection characteristics of developed isolator has been analyzed by the FEM. Consequently, the static load testing and a measure of the effectiveness of a vibration isolator in terms of force transmissibility for developed isolator have been carried out.

• 대한인간공학회지
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• 제26권1호
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• pp.29-37
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• 2007

This study was performed to evaluate the characteristics of transmitted vibration to hand-arm system under different work posture while operating a light-weighted powered hand grinder. For the experiment, 8 different types of wrist posture (natural, unlar-flexion, radual-flexion, flexion, extension, complex posture, and etc.) and 3 types of feed force (20[N], 50[N], 70[N]) were considered. 10 male subjects were employed to polish metal plate with a hand grinder. All of them were normal and healthy with no history and symptom of the work related musculoskeletal disorders in the dominant hand. Vibration acceleration data were recorded with sampling rate, 2048[Hz]. In addition, unweighted overall R.M.S. acceleration at the tool and wrist, and transmissibility between them were used to evaluate factors from the recorded tri-axial vibration acceleration. The results indicate that transmissibility of natural wrist posture was significantly higher than others. In addition, as the feed force becomes larger, the vibration was transmitted in large quantities to hand-arm system through radius.

• 산업경영시스템학회지
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• 제24권69호
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• pp.65-73
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• 2001

The objective of this study is to evaluate the vibration attenuation effects of the different type of gloves and drilling mode while operating a light-weighted powered hand drill. For the experimental design, five different kinds of glove(barehanded cotton partly coated anti-vibration, and open-finger vibration glove) two types of push force level(100N and 200N) and two types of drilling mode(impact and non-impulsive) were considered. Six healthy male subjects were employed to drive screws into a vertically mounted marble plate with a powered hand drill in a randomly ordered experimental conditions. The findings of this study are summarized as follows; (1) It was found that the best combination of overall BMS transmissibility was using impact drilling mode with anti-vibration glove among evaluated experimental conditions (2) The wearing open finger vibration glove in mid-frequency level and anti-vibration glove with impact drill in high-frequency were the best in the result from mean corrected transmissibility equation of ISO 10819.

• 소음진동
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• 제2권4호
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• pp.273-280
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• 1992

The prediction of vibration response of floor is necessary in order to check whether the floor vibration level will satisfy the allowable vibration standard of precise machinery such as electronic microscopes in semiconductor manufacturing plant before the installation of various neighboring equipment facility. In conventional vibration isolation, we were mainly interested in minimization of vibration transmissibility and stabilization of vibration isolation system. But in order to predict vibration response of floor, it is necessary to know exciting force of equipment installed on the floor and the mobility of the floor. We measured the exciting force of the dropped mass assumed as equipment and the mobility of some practical building floor using large impact hammer. And from this we predicted the vibration response of floor on which the mass dropped. This predicted vibration response of floor is compared with measured vibration response. Through upper procedure, we examined the possibility of predicting vibration response of floor from the information of exciting force of equipment and the mobility of floor.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2013년도 춘계학술대회 논문집
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• pp.273-278
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• 2013

This paper presents optimal design procedures of mount based on a magnetorheological (MR) fluid to isolate the vibration in heavy diesel engine system. At first, frequency response and force-displacement transmissibility methods are used to get required damping force that is necessary for effective vibration isolation. From this result, a new type of high damping force engine mount is proposed and the governing equation of Bingham plastic behavior of MR fluid in flow path is mathematically derived under cylindrical coordinates. Finally, parametric design optimization featuring finite element is performed using ANSYS software to get the required damping force in MR mount system which can be used to reduce engine vibration. Damping force of the MR mount is then determined as an objective function in this analysis based on ANSYS. Furthermore, Magnetic analysis is then applied in this process.

• 한국소음진동공학회논문집
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• 제23권5호
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• pp.472-478
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• 2013

This paper presents optimal design procedures of mount based on a magnetorheological(MR) fluid to isolate the vibration in heavy diesel engine system. At first, frequency response and force-displacement transmissibility methods are used to get required damping force that is necessary for effective vibration isolation. From this result, a new type of high damping force engine mount is proposed and the governing equation of Bingham plastic behavior of MR fluid in flow path is mathematically derived under cylindrical coordinates. Finally, parametric design optimization featuring finite element is performed using ANSYS software to get the required damping force in MR mount system which can be used to reduce engine vibration. Damping force of the MR mount is then determined as an objective function in this analysis based on ANSYS. Furthermore, Magnetic analysis is then applied in this process.