• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.453-458
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• 2002

This paper deals with the vibration reduction of hull mount system of ship structures brought by ER smart structures. The hull mount is used to isolate the vibration of equipment from the host structures. Utilizing the tunable characteristics of ER fluids, ER inserts are made in the hull mount structure. Different types of ER inserts are proposed and the vibration characteristics are investigated. A hull mount structure is made and the influence of ER inserts are experimentally studied. An extensive modal test is empirically conducted to identify natural frequencies and mode shapes according to the applied electric field and the types of ER insert. The frequency tunable characteristics of ER inserts can be applied to many mounting structures for vibration reduction.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.348.1-348
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• 2002

This paper deals with the vibration reduction of the hull mount system of ship structures brought by ER smart structures. The hull mount is used to isolate the vibration form the immersed structures. Utilizing the tunable characteristics of ER fluids, ER insert are made In the hull mountint structure. Different types of ER inserts are proposed and the vibration characteristics are investigated. (omitted)

• 한국정보통신학회논문지
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• 제16권11호
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• pp.2569-2574
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• 2012

초계함(천안함급)에 탑재 된 HMS(Hull Mount Sonar) 장비는 능동모드에 적합하도록 설계 되어 있다. 이에 센서 및 시스템 특성이 어뢰 탐지 주파수 대역에 적당하도록 구성되어 있지는 않다. 이에 초계함에 장착 된 기존 HMS 장비를 이용한 어뢰탐지 기능 구현을 위하여, 초계함 함 별 입력 특성을 분석하고, 입력 주파수 신호에 대한 역보상 회로 설계, 입력 신호 크기에 따른 AGC(Auto Gain Control) 기능 구현 및 함별 신호특성에 따른 대역설정 기능을 통하여 함정 별 특성 및 운용환경 특성에 맞는 어뢰방어시스템을 구현하였다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 추계학술대회
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• pp.349-352
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• 2011

초계함(천안함급)에 탑재 된 HMS(Hull Mount Sonar) 장비는 능동모드에 적합하도록 설계 되어 있다. 이에 센서 및 시스템 특성이 어뢰 탐지 주파수 대역에 적당하도록 구성되어 있지는 않다. 이에 초계함에 장착 된 기존 HMS 장비를 이용한 어뢰탐지 기능 구현을 위하여, 초계함 함 별 입력 특성을 분석하고, 입력 주파수 신호에 대한 역보상 회로 설계, 입력 신호 크기에 따른 AGC(Auto Gain Control) 기능 구현 및 함별 신호특성에 따른 대역설정 기능을 통하여 함정 별 특성 및 운용환경 특성에 맞는 어뢰방어시스템을 구현한다.

• 한국소음진동공학회논문집
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• 제13권9호
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• pp.679-687
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• 2003

Shock wave reduction in electrorheological(ER) smart structures is studied. ER insert is a composite structure comprising two elastic outer layers between which is sandwiched layer of ER fluid. When a voltage is applied across the outer layers. the shear modulus and the loss factor of the ER fluid are enabled, and thus the dynamic properties of the composite structure is altered. For the shock wave reduction in a hull mount of a submerged structure, ER inserts are made on the hull mount structure. To investigate the ER insert shape. many types of ER insert pattern are considered. Modal test of ER insert structures is performed to obtain the mode shapes, natural frequencies and the acceleration transmissibility. The acceleration transmissibility is reduced at such a frequency region when an electric field is applied. It is observed that the natural frequencies and mode shapes can be tunable by applying electric field. The ER-inserted hull mount is installed in an integrated system and the overall performance of shock wave reduction is tested. The possibility of shock wave reduction in the hull mount is demonstrated.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.145-151
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• 2008

URN(Underwater Radiated Noise) is one of the important performances of the battle ship related to the stealth. The main source of the URN is the structure-borne noise on the hull. And the pipe vibration transmitted to the hull is the main source of the structure-borne noise when the speed of the ship is lower than CIS(Cavitation Inception Speed). In this paper, the vibration isolator(rubber mount) for the pipe system is described in order to reduce the structure-borne noise transmitted to the hull. The vibrations on the sea-water conveying pipes and their supports are measured in order to know how much vibration occurs on those positions. Based on these test results, the improved design of the rubber mount is suggested by the parametric study and is verified numerically with the pipe and hull model.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.227-231
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• 2014

Underwater radiated noise is one of the vital factors in underwater weapon systems like submarine. A passive elastic mount is an effective reduction method for the vibration from a ship-board machinery transmitted to the hull which is radiated as noise outside the hull. A passive elastic mount shows the limitation on the vibration reduction and needs multi stage mounting system including double stage one to meet the required underwater radiated noise criteria. It is necessary for the multi stage mounting system to consider the large displacement in the underwater shock explosion. So it is difficult to apply the multi stage mounting system in submarine because of space limitation. Also recent navy sonar system are trying to have the capability to detect the ship-borne acoustic signals in the low frequency range. An alternative to the passive mount is an active mount with moving-coil type electromagnetic actuator based on a conventional rubber mount in the low frequency range. In the previous paper, 4 active mounts with moving-coil type electromagnetic actuator based on the rubber mount were installed on the hard floor of the facility, which means no consideration on the elastic foundation effect for the control of the active mounts was taken into account. In this study, an experimental performance analysis on the active mount was carried out using 4 active mounts installed on the cylindrical structure to investigate the elastic foundation effect.

• 한국소음진동공학회논문집
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• 제18권11호
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• pp.1177-1184
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• 2008

URN(underwater radiated noise) is one of the important performances of the battle ship related to the stealth. The main source of the URN is the structure-borne noise on the hull. And the pipe vibration transmitted to the hull is the main source of the structure-borne noise when the speed of the ship is lower than CIS(cavitation inception speed). In this paper, the vibration isolator(rubber mount) for the pipe system is described in order to reduce the structure-borne noise transmitted to the hull. The vibrations on the sea-water conveying pipes and their supports are measured in order to know how much vibration occurs on those positions. Based on these test results, the improved design of the rubber mount is suggested by the parametric study and is verified numerically with the pipe and hull model.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권1호
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• pp.41-55
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• 2015

This study is proposed a new hybrid mount having a moving-magnet type electromagnetic actuator to reduce the vibration transmitted from naval shipboard equipment to the structure of the ship's hull. Optimal design specifications are determined through experimental analysis. The detailed design of the hybrid mount is determined through several design steps with electromagnetic numerical analysis using Maxwell Software(S/W). The hybrid mount that combines a rubber mount and an electromagnetic actuator has a fail-safe function for shock resistance. The mount is fabricated and tested using a universal testing machine to evaluate the design specifications. Finally, numerical simulation of the hybrid mount is performed to confirm control performance and applicability.

• 한국소음진동공학회논문집
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• 제21권2호
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• pp.120-128
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• 2011

This paper presents an efficient method to analyze noise and vibration of marine diesel engines mounted on flexible hull structure. The analysis model should in general include the hull structure, leading to lots of computational efforts. To minimize the computational efforts, in this paper, the transfer synthesis utilizing the receptance at the mounting points is proposed. The procedure is then verified by comparing the results with those from the full model calculation. The effects of flexible hull structure on the acoustic power from engine block are finally investigated. It is found that the effect of the hull is significant when the receptance of hull structure is similar to or greater than that of mount or engine block.