• 제목/요약/키워드: Low Vibration

검색결과 2,166건 처리시간 0.029초

Integrated cable vibration control system using Arduino

  • Jeong, Seunghoo;Lee, Junhwa;Cho, Soojin;Sim, Sung-Han
    • Smart Structures and Systems
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    • 제23권6호
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    • pp.695-702
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    • 2019
  • The number of cable-stayed bridges has been increasing worldwide, causing issues in maintaining the structural safety and integrity of bridges. The stay cable, one of the most critical members in cable-stayed bridges, is vulnerable to wind-induced vibrations owing to its inherent low damping capacity. Thus, vibration mitigation of stay cables has been an important issue both in academia and practice. While a semi-active control scheme shows effective vibration reduction compared to a passive control scheme, real-world applications are quite limited because it requires complicated equipment, including for data acquisition, and power supply. This study aims to develop an Arduino-based integrated cable vibration control system implementing a semi-active control algorithm. The integrated control system is built on the low-cost, low-power Arduino platform, embedding a semi-active control algorithm. A MEMS accelerometer is installed in the platform to conduct a state feedback for the semi-active control. The Linear Quadratic Gaussian control is applied to estimate a cable state and obtain a control gain, and the clipped optimal algorithm is implemented to control the damping device. This study selects the magnetorheological damper as a semi-active damping device, controlled by the proposed control system. The developed integrated system is applied to a laboratory size cable with a series of experimental studies for identifying the effect of the system on cable vibration reduction. The semi-active control embedded in the integrated system is compared with free and passive mode cases and is shown to reduce the vibration of stay-cables effectively.

차량 클러치 스프링 댐퍼의 진동 전달률 해석 및 측정 (Vibration Transmissibility Analysis and Measurement of Automotive Clutch Spring Dampers)

  • 장재덕;김기우;김원진
    • 한국소음진동공학회논문집
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    • 제23권10호
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    • pp.902-908
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    • 2013
  • The input torque ripple induced by combustion engines is a significant source of NVH(noise, vibration and harshness) problem in automotive transmissions. Because this torque fluctuation is primarily transmitted to the input shaft of automotive powertrains(e.g., automatic transmissions) when the lock-up clutches are closed, a torsional damper with helical springs is generally inserted between engine and transmissions to isolate the input vibratory energy, which is essential for the passenger comfort. The torsional vibration isolator exhibits frequency ranges in which there is low vibration transmissibility. However, the isolation performance is currently evaluated through the static torsional spring characteristics. In this study, the transmissibility of torsional spring dampers, essential dynamic performance index for vibration isolator, is first experimentally evaluated.

지반조건의 변화에 따른 SIP 항타진동의 특성에 관한 실험적 연구 (A Study on the Characteristics of Piling Vibration by SIP Method about Variation of Various Earth Conditions)

  • 곽광수;박재영;이병윤;김재수
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2000년도 춘계학술대회논문집
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    • pp.927-932
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    • 2000
  • Recently, construction vibration has caused annoyance for a number of dwellers in nearby construction field and that induced from operating of large construction equipment, has become a very serious issue in our living environment. But, construction vibration standard of our living environment. But construction vibration standard of our country is efficient. Especially, directly blow method(diesel piling method, oil pressure method, etc) has caused much problems of highly impactive vibration. Construction works, in order to solve these problem, will be used SIP(Soilcement Injected Precast Pile) method of low vibration equipment. In this point, this study attempts to survey on the characteristics of piling vibration by SIP method for various earth conditions in construction field. And this study intends to get the basic data to establish a standard about construction vibration.

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320MW 화력발전소 가스 보일러 고 진동 현상 규명 (Phenomenon Examination on High Vibration of NG Boiler in 320MW Thermal Power Plant)

  • 김연환;배용채;이현;김희수;이두영
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2006년도 춘계학술대회논문집
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    • pp.1034-1039
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    • 2006
  • Large-amplitude, combustion-induced oscillations are observed in most systems involving continuous flow, such as aeroengine afterburners, gas boilers and rocket motors. Strong furnace vibration is typically characterized by the presence of well developed standing waves in the furnace, generating high pressure pulsation and causing structural vibration of the furnace walls. 320MW NG boilers have been experienced high vibration frequently since reconstruction works. Excessive furnace vibration was encountered when a burner air rate is suddenly reduced during load zone changed from 270MW to 300MW. An investigation showed that the primary cause of the vibration was induced by combustion low air flow rate. This paper describes phenomenon examination on strong furnace vibration due to the change of boiler operating conditions.

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