• 제목/요약/키워드: phased application

검색결과 67건 처리시간 0.025초

원전 주증기배관 웰더렛 용접부 위상배열초음파검사 적용연구 (A Study on the Application of Phased Array Ultrasonic Testing to Main Steam Line in Nuclear Power Plants)

  • 이승표;김진회
    • 한국압력기기공학회 논문집
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    • 제7권3호
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    • pp.40-47
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    • 2011
  • KSNPs(Korea Standard Nuclear Power Plant) have been applied the break exclusion criteria to the high energy lines passing through containment penetration area to ensure that piping failures would not cause the loss of containment isolation function, and to reduce the resulting dynamic effects. Systems with the criteria are the Main Steam system, Feed Water system, Steam Generator Blowdown system, and Chemical & Volume Control system. In accordance with FSAR(Final Safety Analysis Report), a 100% volumetric examination by augmented in-service inspection of all pipe welds appled the break exclusion criteria is required for the break exclusion application piping. However, it is difficult to fully satisfy the requirements of inspection because 12", 8" and 6" weldolet weldments of Main Steam pipe line have complex structural shapes. To resolve the difficulty on the application of conventional UT(Ultrasonic Testing) technique, realistic mock-ups and UT calibration blocks were made. Simulations of conventional UT were performed utilizing CIVA, a commercial NDE(Nondestructive Examination) simulation software. Phased array UT experiments were performed through mock-up including artificial notch type flaws. A phased array UT technique is finally developed to improve the reliability of ultrasonic test at main steam line pipe to 12", 8" and 6" branch connection weld.

X-대역 2차원 위상배열안테나 빔조향 시스템 개발 (The Development of a Beam Steering System for X-band 2-D Phased Array Antenna)

  • 김두수
    • 한국군사과학기술학회지
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    • 제11권4호
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    • pp.92-98
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    • 2008
  • A beam steering system of X-band 2-D phased array antenna for radar application is developed. The beam steering system consists of real-time command generator, beam steering unit, control PCB of array module and power supply. It plays a role of beam steering and on-line check of phased array antenna. The performance of beam steering system is verified with pulse timing of current control in phase shifters and measurement of far-field of phased array antenna. The developed beam steering system offers basic technology to develop full-scale beam steering system of multi-function radar.

횡파 위상배열 초음파탐촉자를 이용한 원자력발전소 저압 터빈 검사 적용 타당성 연구 (Feasibility Study for Low Pressure Turbine Inspection of Nuclear Power Plant Using Shear Wave Phased Array Ultrasonic Transducer)

  • 윤병식;김용식;김진회
    • 한국압력기기공학회 논문집
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    • 제9권1호
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    • pp.8-14
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    • 2013
  • Steam turbine blades and discs of nuclear power plants are one of the most highly stressed areas of turbine rotor, and periodic inspection of the blade roots is essential for monitoring integrity and preventing turbine failure. Ultrasonic technique is applied for volumetric inspection of blade root. However, the complexity of blade root geometry imposes challenges to inspection of blades and discs. Recently, phased array ultrasonic inspection technology is being applied to numerous power generation inspection applications including turbine rotor. The phased array ultrasonic technique requires customized inspection wedges which are generally necessary to generate effectively higher incident angle. But the usage of this wedge can cause access limitation for the lower stage blades of turbine because of the wedge front length. Therefore, the shear wave phased array probe which can generate high inspection angle without wedge is essentially necessary. In this study, feasibility study is conducted for the shear wave phased array ultrasonic probe application to blade and disc inspection. As results, the experimental results show that the shear wave phased array probe can detect the flaw and measure its size with reliable accuracy. Therefore if this shear wave phased array probe is applied to field inspection of blade and disc, more reliable inspection is expected for turbine having access limitation.

평판 구조물의 영상화를 위한 위상 배열 시스템 개발 및 응용 (Development and Application of Phased Array System for Defect Imaging in Plate-like Structures)

  • 이주경;권영의;이흥선;승홍민;김기연;이준규;김회웅;이호철;김윤영
    • 한국소음진동공학회논문집
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    • 제24권2호
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    • pp.123-130
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    • 2014
  • An ultrasonic magnetostrictive transducer-based phased-array system for imaging defects in plate structures is newly proposed. In that most ultrasonic phased array systems rely on piezoelectric transducers or electromagnetic acoustic transducers, this system has its own unique feature of employing magnetostrictive transducers. Interest in using a phased array system using magnetostrictive transducers has been recently reported for pipe inspection but no such system has been developed for plate inspection. In this investigation, we aim to propose a phased array system using OL-MPTs (Omnidirectional Lamb wave Magnetostrictive Patch Transducers) for plate inspection. The developed system consists of a multi-channel function generator, power amplifiers, preamplifiers and a data acquisition unit. In the process of its development, each of the units must be checked and in doing so, we suggest types of ultrasonic wave experiments that should be carried out. Finally, the phased system using a transducer array composed of eight OL-MPTs is newly configured and is applied for actual crack detection experiments.

Phased Array트랜스듀서에 있어서 구성 압전소자수의 변화에 따른 초음파 빔 전파 특성의 수치 해석 (Numerical Analysis of Ultrasonic Beam Profile Due to the Change of the Number of Piezoelectric Elements for Phased Array Transducer)

  • 최상우;이준현
    • 비파괴검사학회지
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    • 제19권3호
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    • pp.207-216
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    • 1999
  • 일반적인 하나 또는 두개의 압전소자를 사용하는 트랜스듀서에 비하여 다수의 압전소자를 사용하는 어레이 트랜스듀서는 각 압전소자에 가해지는 펄스의 지연시간을 제어함으로써 초음파 빔을 임의의 지점에 집속시킬 수 있고 기계적 구동없이 임의의 방향으로 조향시켜 실시간 주사를 할 수 있는 장점이 있다. 페이즈드 어레이 트랜스듀서의 설계조건은 압전소자의 수. 압전소자의 크기 그리고 압전소자 사이 간격 등 여러가지가 있으며, 본 연구에서는 그 중에서 압전소자수의 변화에 따른 초음파 빔의 특성을 호이겐스의 원리를 이용한 수평횡파의 시뮬레이션을 통하여 평가하였다. 그 결과 초음파 빔은 조향각이 증가 할수륵 음압이 감소하며, 초음파 빔 특성도 점차적으로 분산됨을 알 수 있었고 또한, 초점거리가 증가할수록 초점에서의 집속효과는 감소하고, 압전소자의 수가 증가되면 집속효과는 향상됨을 알 수 있었다.

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수시접수 및 학습효과를 고려한 기간별 재발주 모형에 관한 연구 (The Study of Time Phased Reorder Models for Non-Instaneous Receipt with Learning Effect)

  • 남호기
    • 산업경영시스템학회지
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    • 제19권40호
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    • pp.321-327
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    • 1996
  • Time phased reorder models for non-instaneous receipt was Presented in a recent paper [l]. This paper extends the models under learning effects and learning retention after breaks. The result of this model show that learning and learning retention significantly influence the amount of inventory and production lot size. Sample example demonstrate the application of the proposed methodology.

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물리 학습을 돕기 위한 단계적 상황 교수·학습 전략 및 적용 (Strategy and Application of Phased Context Teaching-Learning for Helping Physics Learning)

  • 송영욱;최혁준
    • 과학교육연구지
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    • 제39권3호
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    • pp.333-342
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    • 2015
  • 이 연구는 단계적 상황 교수자료를 개발하고 대학 물리학 수업에 적용하여 물리 학습에 대한 효과를 조사하는 데 있다. 연구대상은 지방 소재 대학의 사범대학 자연계열 1학년 대학생 총 35명으로 했다. 단계적 상황 교수자료는 상황 이상화하기, 상황 확장하기, 상황 비교하기 단계로 개발하고, 일차원 운동, 이차원 운동, 뉴턴의 운동 법칙 등 6차시 물리 수업에 적용했다. 물리 학습에 대한 효과는 힘 개념 검사지(FCI)와 물리 학습에 대한 신념(MPEX) 설문지를 사용하여 조사했다. 연구결과 단계적 상황 교수자료는 대학생의 힘 개념 변화에는 효과가 있었지만, 물리 학습에 대한 신념에는 유의미한 변화가 없었다. 결론적으로 단계적 상황 교수 학습 전략으로 개발된 교수자료는 학생에게 과학개념을 다양한 상황에 적용하는 기회를 주어 물리 개념 변화를 돕는 데 효과가 있다. 끝으로 연구 결과들을 통해 단계적 상황 물리 수업에 대한 교육적 시사점을 논의했다.

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FRP 박스부재의 결함평가를 위한 위상배열초음파 적용성 평가 (Phased Array Ultrasonic Application for Defects Estimation of FRP Box Member)

  • 곽계환;양동운;김호선;이호현;윤국현
    • 한국농공학회논문집
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    • 제52권5호
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    • pp.69-76
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    • 2010
  • The structural material with the highest possibility of new materials that will be used in the future construction field is fiber reinforced polymer. The current studies on FRP members by using such excellent material characteristics mostly focused on stability, composite problem, and durability of FRP members. The initially constructed FRP members secure excellent stability and durability compared to reinforced concrete and steel materials, but measures for defections during the periodical inspection, methods for detecting breakages, and maintenance and reinforcement are not insufficient. Accordingly, this study proposed a measurement system using the FRP sensor to evaluate the safety of the FRP modular box member, and applied the phased array ultrasonic technique to detect the defects and damage likely to occur during the performance period.

Simulation of Ultrasonic Beam Focusing on a Defect in Anisotropic, Inhomogeneous Media

  • Jeong, Hyun-Jo;Cho, Sung-Jong;Erdenetuya, Sharaa;Jung, Duck-Yong
    • 비파괴검사학회지
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    • 제31권6호
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    • pp.635-641
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    • 2011
  • In ultrasonic testing of dissimilar metal welds, application of phased array technique in terms of incident beam focusing is not easy because of complicated material structures formed during the multi-pass welding process. Time reversal(TR) techniques can overcome some limitations of phased array since they are self-focusing that does not depend on the geometrical and physical properties of testing components. In this paper, we test the possibility of TR focusing on a defect within anisotropic, heterogeneous austenitic welds. A commercial simulation software is employed for TR focusing and imaging of a side-drilled hole. The performance of time reversed adaptive focal law is compared with those of calculated focal laws for both anisotropic and isotropic welds.

슬롯결합구조를 갖는 이동통신 기지국용 마이크로스트립 위상배열 안테나의 설계 (A design of the microstrip phased array antenna with the slot-coupled structure for the base station of mobile communication)

  • 장정필;장병준;윤영중;박한규
    • 한국통신학회논문지
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    • 제21권12호
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    • pp.3205-3214
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    • 1996
  • In this paper, the microstrip phased array antennas with coupling-slots for the base station of mobile communication is proposed and anlyzed with accurate analysis method which is based on both reciprocity principle and full-wave analysis. The basis functions used for the numerical analysis are determined depending upon the accuracy, convergence properties of the solution, and the computation time. The patch uses 3 EB mode and the slot uses IPWS mode. The designed phased array antenna has 8 slot-coupled microstrip patch array elements and the beam scanning capability is obtained by using the 4-bit PIN-diode phase shifters as switching devices which are consisted of the loaded line phase shifters for 30.deg. and 60.deg. and the reflection type phase shifters for 90.deg. and 180.deg. repectively. The 4-bits phase shifters which aremade by connecting each phase shifter have about 2.deg.-3.deg. phase errors and their insertion loss are about 3dB for each phase state. The fabricated 8-element phased array antenna with 4-bits phase shifters provides 12.deg.-14.deg. beamwidths depending on the scanning angle and is capable of scanning its beam to .+-.45.deg. with 9.deg. intervals, and the gain 12dBi. The overall results show that the slot-coupled phased array antenna has great advantages of wideband, high gain and reduced spurious radiation. Also, the antenna can be made small and thin. Furthermore, the scanning property of this antenna allows for its application in several areas, such as mobile communication system and PCS.

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