수전달 진동 피폭 저감을 위한 방진 장갑의 성능 평가

최석현 ( Seok Hyun Choi ),홍석인 ( Seok In Hong ),장한기 ( Han Kee Jang ) 한국산업위생학회 2008 한국산업보건학회지 Vol.18 No.1

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, 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. Whole procedure of ISO 10819:1996 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 9 anti-vibration gloves where each glove was tested twice a subject. Average and standard deviation of the corrected vibration transmissibility were also calculated. All tested gloves fulfilled criterion for M-spectrum(TR(M)<1.0), but one glove fulfilled criterion for H-spectrum(TR(H)<6.0 ).

방진 장갑 진동 전달률 측정 시스템 개발

최석현(Choi, Seok-Hyun),홍석인(Hong, Seok-In),장한기(Jang, Han-Kee),박태원(Park, Tae-Won) 한국소음진동공학회 2006 한국소음진동공학회 논문집 Vol.16 No.6

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.

바닥진동에 기인한 도시철도 실내소음 측정 및 방진설계에 관한 연구

김병삼 ( Byoung-sam Kim ) 한국환경기술학회 2013 한국환경기술학회지 Vol.14 No.4

최근 철도의 소음과 진동이 육체적, 정신적으로 건강에 큰 영향이 있으며, 매우 심각한 사회적 문제로 대두되고 있다. 따라서 철도 차량의 소음과 진동의 예측은 매우 중요한 일이 되었다. 철도차량에 의한 소음원은 크게 3가지로 구분된다. 첫 번째는 공력소음이다. 철도 주행시 철도 차량 주변에서의 공기역학적인 소음을 말한다. 두 번째는 휠/레일 소음이다. 일반적으로 전동소음이라고도 한다. 휠과 레일 사이의 접촉에 의한 소음을 말한다. 공기역학적인 소음과 전동소음은 차량의 속도에 비례하고 있으며 철도 차량 주변의 공기 변화에 의해 소음이 발생하는 공기전파음이다. 세 번째는 구조진동음이다. 구조진동음은 주로 저주파수대역에서 소음을 발생하는 것이 특징이다. 즉 철도차량의 진동에 의해 소음이 발생한다. 본 연구에서는 도시철도 차량의 바닥 진동이 도시철도 차량의 실내소음에 미치는 영향에 대하여 조사하였다. 본 연구 결과를 통해 도시철도 차량의 바닥진동이 차량의 실내소음에 미치는 영향에 관한 기초 자료를 확보할 수 있고, 도시철도 차량의 바닥진동을 저감할 수 있는 방진재의 물리적 특정치를 제시하였다. In recently, rail traffic noise and vibration have an serious effect for physical and spiritual health and has become a very serious environmental pollution. So the prediction of noise and vibration for train is very important thing. There are three sources of wayside noise by the train. The first is the aerodynamic noise. The second is wheel/rail noise. And the last is structure-borne noise. The major source of railway noise is the wheel/rail noise caused by the interaction between the wheels and rails. The structureborne noise is mainly a low frequency problem. This study attempts to surveys the characteristics of indoor noise of subway due to floor vibration. This study intends to get a basic data in establishing a indoor noise of subway due to floor vibration and proposed physical property for the anti-vibration material.

전자장비의 진동 보호를 위한 2축 레버형 반공진 진동 절연기의 설계와 분석

임성준(Sung-Jun Lim),송용진(Yong-Jin Song),최태규(Tae-Kyu Choi),정회인(Hoe-In Jung),김상현(Sang-Hyun Kim),이종학(Jong-Hak Lee),박경수(Kyoung-Su Park) 한국소음진동공학회 2023 한국소음진동공학회 논문집 Vol.33 No.4

This study proposes an extended model of a two-axis horizontal dynamic anti-resonance vibration isolator (DAVI). Our approach involves the incorporation of a rotatable and movable pivot pin, enabling the design of two lever mechanisms oriented along different axes to avoid disturbing the behavior of the DAVI mass. This design minimizes mutual interference and provides effective vibration isolation for both axes simultaneously. The Finite Element Method (FEM) analysis is employed to demonstrate anti-resonance and identify the corresponding band-stop filter region. Static analysis confirms the structural stability of the system under gravitational forces. Using the constructed FE model, transient analysis evaluates the vibration attenuation performance under two-axis vibration conditions, including sine signals with a 70 Hz harmonic component and measured real battleship vibration data. By applying the 2-axis DAVI, the vibration is significantly reduced, especially at 70 Hz. Furthermore, we compare the impact of restricting the pivot pin movement on vibration attenuation through additional transient analysis.

Vibration Absorber Design and Finite Element Analysis Model Building and Experimental Ion to Prepare the Anti-Vibration Design for the Flight Structure

김준수(Jun Soo Kim),박성우(Sung Woo Park),강성욱(Sung Wook Kang),조지현(Ji Hyun Cho) Korean Society for Precision Engineering 2017 한국정밀공학회지 Vol.34 No.5

For this study, A vibration attenuation of the vibration absorber that is attached to the flight structures was carried out. Flight structures are stabilized to allow for operations in various operating environments; however, as the size and weight of the flight structures are reduced, to meet the requisite performance, the operating-environment-induced vibrations lead to a degraded operating performance; therefore, the reduction of these vibrations should lead to an increased operating performance. The vibration absorber includes a compliant energy-storage device, such as a spring, and is mass secured to the energy-storage device. In this study, the research to prepare the anti-vibration design of the flight structures was accomplished, and the vibration of the flight structures was analyzed using the finite element analysis; accordingly, a vibration experiment for the verification of the result of the finite element analysis was also conducted. Further, the design guidelines of a tuned mass damper were obtained.

초정밀작업을 위한 제진시스템의 동역학 모델링 연구

손성완,장성호,백재호,전종균,권영철,Son, Sung-Wan,Jang, Sung-Ho,Baek, Jae-Ho,Chun, Chong-Keun,Kwon, Young-Chul 한국산학기술학회 2009 한국산학기술학회논문지 Vol.10 No.1

공기스프링을 감쇠기로 사용하는 방진대는 넓은 주파수대역에서 우수한 진동 절연성능을 가짐으로 널리 사용되어 왔다. 하지만 공기스프링은 구조적으로 저강성, 저감쇠의 특성을 가지고 있으므로 외란에 의해 쉽게 가진되어 안정성이 떨어지는 문제가 있다. 이에 공기스프링과 같은 수동소자만을 이용한 수동제어 형식의 보완을 위해 능동 및 반능동 방식의 감쇠기가 제안되고 연구되고 있다. 따라서 본 연구에서는 이러한 수동형 제진대의 능동 및 반능동제어를 위한 동역학적 해석에 관하여 연구하였다. 제진대의 제어시스템 구현을 위하여 6 자유도 제진대의 물리적인 특성에 기초한 동역학적 모델을 정립하고 해석 및 실험을 통해 동역학 모델의 적용가능성을 검증하였다. The anti-vibration tables that use air suspensions as dampers have been widely used due to their high anti-vibration performance in wide frequency band. However, they face a problem of easily accelerating the vibration when triggered by external force because their air suspensions have low rigidity and dampness. In response, there has been a study on active/semi-active dampers that use only the passive components like air suspensions to complement the passive-control format. Thus, we have dynamically analyzed the active/semi-active control of such passive anti-vibration tables. To demonstrate the anti-vibration table's control system, we have also constructed a kinetic model based on the physical characteristics of an anti-vibration table with 6 degrees of freedom and verified its applicability through analysis and experiments.

Design of anti-vibration mounting for 140A class alternator for vehicles

Zhen Qin,손형일,류성기 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.11

The alternator is a core component of modern vehicles that supplies power to all the electrical equipment when the engine is running. It is fitted to the engine bracket with long bolts going through the frame mountings. Due to the strong vibration from the engine, it is extremely important to improve its anti-vibration performance to extend the life of the alternator. This study presents a new anti-vibration mounting design for the alternator frame based on a 140A class alternator used in a best-selling sport utility vehicle (SUV). In this study, UG (unigraphics NX) was used to generate 3D models of the alternator and the finite element analysis software ABAQUS was used to simulate the vibration experiment. Then through a series of verification experiments, results were obtained which show that the new separated mounting design has obvious improvements in terms of the anti-vibration characteristic, as compared to the current design. The current work will be used for resonance reduction during design stages in future works.

Sensitivity Analysis of Anti-resonance Frequency for Vibration Test Control of a Fixture

Jeong, Weui-Bong,Yoo, Wan-Suk,Kim, Jun-Yeop The Korean Society of Mechanical Engineers 2003 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.17 No.11

The test specimen in environmental vibration test is connected to the fixture through several attachment points. The forces generated by the shaker must be transmitted equally to all attachment points. The forces transmitted to attachment points, however, are different because of the flexural vibration of the fixture. The variations of the transmitted force cause the under-test, especially at anti-resonance frequencies, in vibration test control. Anti-resonance frequencies at the attachment points of the fixture must be same in order to avoid the under-test in vibration test control. The structural modification of the fixture is needed so that anti-resonance frequencies at attachment points have the same value. In this paper, the method to calculate the anti-resonance frequencies and those sensitivities is presented. This sensitivity analysis is applied to the structural modification of the fixture excited at multi-points by the shaker. The antiresonance frequencies at the attachment points of the fixture can have the same value after structural modification, and the under-test in the vibration test control can be removed. Several computer simulations show that the proposed method can remove the under-tests, which are not removed in conventional vibration test control.

Vibrational Energy Properties of Twin–Block Ballastless Track with Anti–vibration Structure on Bridge by Power Flow Analysis

Na Fu,Zhenhang Zhao,Yutao Liu,Yuxiang Li 대한토목학회 2022 KSCE JOURNAL OF CIVIL ENGINEERING Vol.26 No.2

This article aims to investigate the vibrational energy properties of the twin–block ballastless track with anti–vibration structure (TBTAS) by mobility power flow method. Power flow of the components in TBTAS and bridge are deduced and power flow transfer rate is proposed to present the vibrational energy transmission property of the TBTAS–bridge system. Power flow of rail, twin–block slab and bridge in frequency domain is calculated based on a train–track–bridge interaction model. The effect of the stiffness of the elastic pad on power flow is discussed. The results show that the power flow of the rail exhibits a broad peak in the frequency range of 100 − 400 Hz which corresponds to the broad peak of the rail mobility and exhibits another peak around 1,000 Hz which is the pinned–pinned vibration frequency of the rail. By using elastic pad, the power flow of the bridge reduces by a maximum of 43 dB in the frequency range of 1 − 1,000 Hz. The power flow transfer rate shows that the vibrational energy concentrates in the slab. The vibrational energy of slab and bridge reaches the balance when the stiffness of the elastic pad is 40 MPa/m.

The V-shaped band-stop vibration isolator inspired by middle ear

Kim, Gi Woo,Kang, Jaeyoung Elsevier 2019 Applied acoustics Vol.150 No.-

<P><B>Abstract</B></P> <P>In this study, we present the new design of the band-stop filter-type vibration isolator featuring a lever structure. A V-shaped folded lever inspired by the middle ear of the human auditory system consisting of three tiny hinged bones (ossicles): the malleus, the incus, and the stapes, is explored as an effective new method for band-stop vibration isolators. The proposed vibration isolator is found to be the more generic lever-type isolator allowing the higher geometric freedom in the mechanical isolator design. It is shown that the anti-resonance frequencies can be tuned by design parameters such as the ratio of primary mass to auxiliary mass, the lever ratio, the lever angle, and so on. The numerical results are experimentally validated through the anti-resonance frequency and its phase.</P>