• Title/Summary/Keyword: Vibration experiment

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Analysis of a transient vibration response caused by Water Hammer in a pipe-line system (수격 현상에 의한 파이프의 과도진동응답 해석)

  • 조성문;서영수;정의봉;정호경
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.05a
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    • pp.119-124
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    • 2004
  • A water hammer mostly comes out when a valve fixed at the downstream end of the pipe-line system is rapidly closed or opened. A simple phenomenon of water hammer is often caused around us, and this phenomenon imperils the pipe systems occasionally. In this paper, we confirmed the phenomenon of water hammer by an experiment and forecasted a change of pressure in the pipe-line system by a numerical method. Also a vibration response, which is caused by water hammer, of the pipe-line system confirmed by an experiment and analyzed by a numerical method.

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Experiment on Vibration Control of Beam Using Active Constrained-Layer Damping Treatment (능동구속감쇠 기법을 이용한 보의 진동제어 실험)

  • 강영규;최진영;김재환
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.4
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    • pp.52-57
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    • 2001
  • The flexural vibration of aluminum beams with active and passive constrained-layer damping has been investigated experimentally to design a structure with maximum possible damping capacity. Piezoelectric film is used as a sensor and piezoceramic as an actuator for the negative velocity feedback control. The experimental results are compared with those by the finite element analysis. This paper shows the effectiveness of active constrained-layer damping treatment through experiments, and we have carried out an experiment to study the effect of beam thickness.

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Optimal Design of Micro Actuator Plate Spring Considering Vibration Characteristic (진동 특성을 고려한 마이크로 엑추에이터 판 스프링의 최적설계)

  • 이종진;이호철;유정훈
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2003.11a
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    • pp.220-225
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    • 2003
  • Recent issue of optical actuator is applying to mobile device. It leads actuator to become smaller than conventional type. This paper proposes the design of micro actuator plate spring and analysis of its vibration characteristic. Considering natural frequency of spindle motor, 1st and 2nd eigenfrequency of micro actuator must avoid its natural frequency. First, magnetic circuit is designed by using fine pattern coil and magnetic force is acquired by simulation program. Then, concept design is achieved by topology optimization. From concept design, micro actuator plate spring is embodied through DOE(design of experiment). Finally, considering vibration characteristic simultaneously, optimal plate spring design is determined by RSM(response surface method).

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The Design of Radial Magnetic Force Equilibrium for Reduction of Vibration in IPM Type BLDC Motor (진동 저감을 위한 IPM type BLDC 전동기의 가진력 평형화 설계)

  • Lee, Gyeong-Deuk;Lee, Won-Sik;Kim, Gyu-Tak
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.2
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    • pp.298-303
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    • 2016
  • In this paper, the vibration source of IPM type BLDC motor was analyzed by finite element method. The main causes of the electrical vibration were RMF(Radial magnetic force) and cogging torque. It was designed model of minimized cogging torque and RMF equilibrium. Design models were selected the optimum model using the design of experiment method. And, the vibration experiment was carried out through prototype machine of each model. Finally, the experimental results were compared with the analysis ones.

Position and Vibration Control of a Spatial Redundant Flexible Manipulator by using Pseudo-inverse of Jacobian (유사 역행렬을 이용한 여유자유도 3차원 유연 매니퓰레이터의 위치 및 진동제어)

  • Kim, Jin-Su
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.12
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    • pp.66-72
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    • 2001
  • In this paper, by using pseudo-inverse matrix of the spatial redundant flexible manipulators, a position control method and its effect in vibration suppression was presented. Vibration suppression control was developed using lumped mass spring model of the flexible manipulators. With 2 elastic links and 7 rotory joint manipulator ADAM, (1)position control for no redundancy, and (2)position control for one redundant DOF(degree of freedom) were tested. The objective of this experiment is to show the effect of position control, using pseudo-inverse matrix. toward the improvement of operation, and at the same time, to reduce the vibration of the link and the magnitude of the joint torque.

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A Study of Noise Reduction in Hard Disk Drive (하드디스크 드라이브에서의 소음 저감에 관한 연구)

  • 곽주영;손진승;이행수;홍민표;고정석;조은형;좌성훈
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2001.11b
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    • pp.579-585
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    • 2001
  • This paper proposed a method of reducing a noise in hard disk drive. This method is performed through three parts of procedures. First procedure is sound-oriented experiment, which contains sound intensity techniques and measurements of sound pressure level and sound power. Second is vibration-oriented experiment, which contains FRF(Frequency Response Function) analysis and disk vibration reduction techniques. And the third is computer-oriented simulation, which contains modal analysis and force vibration analysis using ANSYS and sound radiation prediction using SYSNOISE. As these three parts can affect with each other, they should be considered and conducted simultaneously. Through this procedure sound power is measured 2.7 Bels in idle-spinning mode, which is the lowest noise level in the HDD industries.

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Development of Remote Vibration Measurement System Using the Internet (인터넷을 이용한 원격 계측 시스템 개발)

  • Kwak, Moon-Kyu
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.11a
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    • pp.322-326
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    • 2000
  • This paper is concerned with the development of remote vibration measurement system using the internet. Recently, various techniques are developed based on the advance of the internet environment. In this study, we developed the remote vibration measurement system using the internet server programming technique, the client programming technique, the GPIB programming, and the A/D, D/A programming techniques. Hence, we can control the measurement devices remotely. The feasibility of the system is validated using the experimental setup. The output of the D/A is connected to the small exciter and the piezoceramic sensor is connected to the A/D port. By sending out the exciting signal to the structure, we can collect the response. The experiment shows that the proposed idea works well. Another experiment consists of the function generator and the low-pass filter circuit. The wave form, amplitude, and the frequency of the function generator is controlled by the GPIB program and the output of the circuit is collected by the A/D port. The output is then displayed in HTML format.

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Vibration experiment of precision stage that use laser vibrator (비접촉식 진동측정 장치를 이용한 정밀 스테이지의 진동특성 평가시험)

  • Lee, Jae-Woo;Lee, Kang-Wook;Yim, Hong-Jae
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.1224-1230
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    • 2007
  • In this study, a new modal test method is presented to evaluate vibration characteristic of the nano imprint stage system. Since it is difficult to measure vibration level without contacting the machine component, non contacting modal test method, laser scanning system is ultrared. Finite element analysis results are compared with the modal test results.

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The Change of Total Weight and Food Consumption of Abalone, Haliotis discus hannai under a Vibration and Noise (소음.진동에 따른 참전복(Haliotis discus hannai)의 전중량 및 먹이섭식량 변화)

  • Jeong, Hyeong Taek;Kim, Yeong Sik;Choe, Sang Deok
    • Journal of Environmental Science International
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    • v.13 no.6
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    • pp.581-589
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    • 2004
  • This paper describes the amount of food consumption and the change of total weight of abalone under a vibration with noise that can be occurred due to piling work. This experiment was conducted in the aquarium in Yosu National University. In normal situation the juvenile stage shell's(total length is 1~1.5cm) amount of food consumption was 0.81g, the middle stage shell(total length is 3~3.5cm) was 13.61g, and the adult stage shell (Total length is 7~7.5cm) was 43.l9g per 5 organisms in 24 hours, while the experimental group was observed low numerical value compared normal groups. The abalones' food consumption and total weight in both groups, the intermittent and continuance impact with noise and vibration, was reduced during this experiment. The abalones' food consumption and total weight in the experimental groups without vibration were recorded slightly high numerical value than the experimental groups with noise and vibration. Based on this experimental data we could conjecture the noise and vibration are harmful factors to bring up a physiological stress to abalones. Especially, the vibration impact by piling works could produce a considerably unfavorable effect to the abalones than noise impact.

Studies on the Nutrition under Abnormal Environment(I) -Nutrition under Vibration- (이상환경하(異常環境下)의 영양문제(營養問題) 연구(硏究)(제1보) -진동하(振動下)의 영양문제(營養問題)-)

  • Yu, Jong-Yull
    • Journal of Nutrition and Health
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    • v.4 no.4
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    • pp.15-23
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    • 1971
  • On the assumption that the supplementation of certain nutrients or foods to the rice diet (low protein, low fat, and low vitamins) may decrease, to some extent, the degree of suffering from abnormal environments, such as vibration, noises, gases, dusts, smog etc. a series of experiments were started. As the first report the nutrition under vibration was studied in this experiment. Sixty (60) young growing male rats weighing about 65 grams were used, grouping to five (5) groups, twelve (12) rats each group. They were fed on the following five (5) experimental diets: rice diet (basal diet), rice diet+casein, rice diet+vitamins, rice $diet+{\alpha}-tocopherol$, and rice diet+ginseng powder (see the tables 1 and 2) for the period of 14 weeks experiment. During the experiment period the half number of the rats of each group were exposed to the three (3) hours vibration every day. The protective effect of each diet against the vibration may be summarized as follows. 1. The growth of rice diet group was impaired significantly under vibration, However, those of other groups (protein-supplemented, vitamin-supplemented, ${\alpha}-tocopherol-supplemented$ and ginseng-supplemented groups) were impaired much less compared with rice diet group. 2. The feed efficiency of the rice diet group was decreased significantly under vibration. It is estimated that the biological availability of nutrients was impaired under this environment. On the other hand, the feed efficiencies of protein supplemented, of vitamin supplemented, and of ginseng supplemented groups were not decreased under vibration, statistically. 3. There is tendency that the food spillages of vibration groups are higher than those of non-vibration groups. Especially it seems true in the case of rice diet group. The food spillage may be, to some extent, related with mental nervousness of animals. From the point that the food spillage of ginseng supplemented group is significantly lower than those of other groups it is thought ginseng acts some good role in protecting nervous system from suffering from vibration. 4. In all groups except protein supplemented group, liver fat of vibration group tends to be higher than that of non-vibration group. 5. It shows that, in general, the serum alkaline phosphatase activity of the vibration group is significantly higher than that of the non-vibration group. It seems that there may be, to some extent, corelation between the amount of liver fat and serum alkaline phosphatase activity. 6. There is tendency that, in rice diet group, the organs of vibration group are smaller than those of non-vibration group, especially lung is so. It is thought that this may be due to the poor growth of whole body size in vibration group.

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