PAL-XFEL 빔라인 허치 구조물 개발

김승남(Seungnam Kim),김명진(Myeongjin Kim),김성한(Seonghan Kim),김영찬(Yeongchan Kim),신호철(Hocheol Shin),김지화(Jihwa Kim),김경숙(Kyeongsuk Kim),김광우(Kwangwoo Kim),엄인태(Intae Eom) 한국소음진동공학회 2016 한국소음진동공학회 논문집 Vol.26 No.5

The hutches which are installed in the beamline are largely classified into two, i.e XPP (X-ray pump probe) and CXI (Coherent X-ray image). Laser room is installed on the hutch and provides laser to XPP and CXI simultaneously. And two hutches have heavy crane to install some optics equipments. Safety and reliability of hutch structures should be taken into account for the precise operating of the laser facilities, so vibration analysis is essential to do this. The main purpose of vibration analysis is to install hutch structures with large stiffness. We have changed materials specification several times to install hutch structures having strong stiffness. Now hutch structures were installed and checked vibration status at laser room and XPP hutch. The results of laser table and robot arm satisfy vibration criteria. This paper explains about the design and vibration analysis of hutch structures.

Nondestructive Testing of Residual Stress on the Welded Part of Butt-welded A36 Plates Using Electronic Speckle Pattern Interferometry

Kim, Kyeongsuk,Jung, Hyunchul Korean Nuclear Society 2016 Nuclear Engineering and Technology Vol.48 No.1

Most manufacturing processes, including welding, create residual stresses. Residual stresses can reduce material strength and cause fractures. For estimating the reliability and aging of a welded structure, residual stresses should be evaluated as precisely as possible. Optical techniques such as holographic interferometry, electronic speckle pattern interferometry (ESPI), Moire interferometry, and shearography are noncontact means of measuring residual stresses. Among optical techniques, ESPI is typically used as a nondestructive measurement technique of in-plane displacement, such as stress and strain, and out-of-plane displacement, such as vibration and bending. In this study, ESPI was used to measure the residual stress on the welded part of butt-welded American Society for Testing and Materials (ASTM) A36 specimens with $CO_2$ welding. Four types of specimens, base metal specimen (BSP), tensile specimen including welded part (TSP), compression specimen including welded part (CSP), and annealed tensile specimen including welded part (ATSP), were tested. BSP was used to obtain the elastic modulus of a base metal. TSP and CSP were used to compare residual stresses under tensile and compressive loading conditions. ATSP was used to confirm the effect of heat treatment. Residual stresses on the welded parts of specimens were obtained from the phase map images obtained by ESPI. The results confirmed that residual stresses of welded parts can be measured by ESPI.

Nondestructive Testing of Residual Stress on the Welded Part of Butt-welded A36 Plates Using Electronic Speckle Pattern Interferometry

Kyeongsuk Kim,정현철 한국원자력학회 2016 Nuclear Engineering and Technology Vol.48 No.1

Most manufacturing processes, including welding, create residual stresses. Residualstresses can reduce material strength and cause fractures. For estimating the reliabilityand aging of a welded structure, residual stresses should be evaluated as precisely aspossible. Optical techniques such as holographic interferometry, electronic speckle patterninterferometry (ESPI), Moire interferometry, and shearography are noncontact means ofmeasuring residual stresses. Among optical techniques, ESPI is typically used as anondestructive measurement technique of in-plane displacement, such as stress andstrain, and out-of-plane displacement, such as vibration and bending. In this study, ESPIwas used to measure the residual stress on the welded part of butt-welded American Societyfor Testing and Materials (ASTM) A36 specimens with CO2 welding. Four types ofspecimens, base metal specimen (BSP), tensile specimen including welded part (TSP),compression specimen including welded part (CSP), and annealed tensile specimenincluding welded part (ATSP), were tested. BSP was used to obtain the elastic modulus of abase metal. TSP and CSP were used to compare residual stresses under tensile andcompressive loading conditions. ATSP was used to confirm the effect of heat treatment. Residual stresses on the welded parts of specimens were obtained from the phase mapimages obtained by ESPI. The results confirmed that residual stresses of welded parts canbe measured by ESPI.

Micro-Structure Measurement and Imaging Based on Digital Holography

Kyeongsuk Kim,Hyunchul Jung,Hoseob Chang,Changdoo Kee,Naseem Akhter 한국비파괴검사학회 2010 한국비파괴검사학회지 Vol.30 No.3

Advancements in the imaging and computing technology have opened the path to digital holography for non-destructive investigations of technical samples, material property measurement, vibration analysis, flow visualization and stress analysis in aerospace industry which has widened the application of digital holography in the above fields. In this paper, we demonstrate the non-destructive investigation and micro-structure measurement application of digital holography to the small particles and a biological sample. This paper gives a brief description of the digital holograms recorded with this system and illustratively demonstrated.

적외선 열화상 기술을 이용한 응력측정에 관한 연구

김경석(Kyeongsuk Kim),정현철(Hyunchul Jung),박찬주(Chanjoo Pack),김동수(Dongsoo Kim),정덕운(Dukwoon Jung),장호섭(Hosub Chang) 대한기계학회 2009 대한기계학회 춘추학술대회 Vol.2009 No.11

In this study, the method of measuring stress non-contact and non-destructive using Lock-in infrared thermography(IRT) is introduced. A object under load emit a part of energy as a thermal energy with variation. The stress was measured based on the thermoelastic theory that the emitted infrared light could be converted to the stress. In experiment, The surface temperature measured by Lock-in infrared thermography is calculated to the stress based on thermoelastic equation. Also, the reliability of those data were verified by comparing with the finite element analysis. The infrared thermography technique has merits that it can show the distribution of stress of the specimen in a short time and real-time without destructing and contacting the specimen.

적외선 열화상 기술을 이용한 원자력 배관의 온도측정과 보정에 관한 연구

김경석(Kyeongsuk Kim),정현철(Hyunchul Jung),박찬주(Chanjoo Pack),김동수(Dongsoo Kim),정덕운(Dukwoon Jung),장호섭(Hosub Chang) 한국비파괴검사학회 2009 한국비파괴검사학회지 Vol.29 No.5

열화상 카메라와 대상물의 측정 위치에 따른 방사각도에 따라 방사율은 달라지게 된다. 이로 인해 열화상 시스템을 이용한 온도 측정시 나타나는 온도 분포는 절대적 온도로 볼 수 없다. 대상체의 실제 표면온도가 일정하더라도 열화상 카메라로 측정된 온도는 방사율 값에 따라 오차를 가지게 된다. 본 논문에서는 동일 온도로 가열된 원통 형태를 가지는 대상체와 평면 형태를 가지는 대상체의 온도를 열화상 카메라를 이용하여 측정하였다. 측정된 표면 온도값을 통하여 화각에 의한 방사율 보정표와 방사각도의 영향에 의한 반사율 보정식을 구하였으며 이를 바탕으로 측정 온도의 오차보정을 수행하였다. 그리고 방사 각도와 화각에 따른 온도 영향을 원자력 배관의 결함 검출에 적용하여 더욱 신뢰성 있는 표면 온도값을 획득하였다. The emissivity is different because the emitted angle changes according to the position of the infrared thermography camera and object. Because of this, the temperature distribution expressed when measuring the temperature by using the infrared thermography system is not the accuracy temperature. Although the real surface temperature is constant, the temperature measured by using infrared thermography camera have error in accordance with the value of emissivity. In this paper, the temperatures of the round cylindrical object and the flat square object that heated to the equal temperature were measured by infrared thermography camera. The emissivity calibration formula and correction table are made with the affect of the view angle and emission angle form the surface temperature value. The error of measured temperature values are corrected by using the emissivity calibration formula and correction table, and apply to defect detection of the nuclear power plant pipe. From the calibration method, reliability surface temperature values were obtained.

적외선열화상을 이용한 원자력발전소 감육 배관의 결함 검출

김경석(Kyeongsuk Kim),장호섭(Hosub Chang),홍동표(Dongpyo Hong),박찬주(Chanjoo Park),나성원(Sungwon Na),김경수(Kyungsu Kim),정현철(Hyunchul Jung) 한국비파괴검사학회 2010 한국비파괴검사학회지 Vol.30 No.2

절대온도(OK) 이상의 온도를 가지고 물체는 표면온도에 대응하는 적외선 파장대역에서 적외선 에너지를 방출하게 된다. 적외선열화상은 적외선 파장대역에 반응하는 검출기를 이용하여 검출된 적외선 량을 온도로 변환하고 사용자에게 적외선영상을 실시간으로 제공하는 비파괴검사 방법이다 원자력발전소의 배관은 부식, 피로 등으로 인해 두께가 얇아져 큰 사고로 이어질 수 있는 결함이 발생하므로 이를 위한 효율적인 비파괴검사 시스템이 요구되고 있다. 따라서 본 연구에서는 적외선열화상 카메라로 측정한 온도와 배관의 결함 깊이 및 크기와의 상관관계를 알아보고 이를 원자력발전소 배관에 적용하여 결함을 검출하는 연구를 수행하였다. The infrared energy is emitted in the infrared wavelength range that corresponds to the surface temperature of a object which has temperature that is over the absolute the temperature(OK). The infrared thermography (IRT) is a non-destructive testing method that provides thermal video for the user in real-time by converting the infrared quantity that is detected by the infrared detector into temperature. The pipes of nuclear power plant(NPP) could be thinned by the corrosion and fatigue and the defect could lead to a big accident. For this reason, the effective non-destructive testing method is necessary. In this study, the relationship between the measured temperature and the defect depth or size of NPP pipes were recognized and that was applied to detect the wall thinning defects of NPP pipes.

열화상기술을 이용한 모멘트 변화에 따른 피로균열진전 연구

김경석(Kyeongsuk Kim),정현철(Hyunchul Jung),박찬주(Chanjoo Pack),정덕운(Dukwoon Jung),장호섭(Hosub Chang) 한국생산제조학회 2010 한국생산제조학회지 Vol.19 No.3

The objective of this study is to propose an effective method for measurement and analysis of fatigue crack. A technique that can measure the statue of fatigue crack propagation fast and correctly for enhancing safety of constructions and securing reliability is necessary. Moreover, the crack propagation behavior characteristics evaluation technique has to be developed using this technique. In this paper, fatigue crack was caused via the fatigue experiment with repeated load on the CT specimen that is made up of STS304. Fatigue crack propagation was measured by tracing the position of the maximum temperature according to the cycles using infrared thermography. The crack growth characteristics was evaluated by applying the moment values on the measuring area to the measured value. As a result of this study, the possibility that the infrared thermography could be applied to measure the fatigue crack was identified. Moreover, it was identified that fatigue crack propagation have a relationship with the moment value of construction.

ESPI를 이용한 자외선조사량에 따른 폴리머애자의 탄성계수 변화 연구

김경석(Kyeongsuk Kim),김동수(Dongsoo Kim),장호섭(Hosub Chang),박찬주(Chanjoo Park),장완식(Wansik Jang),정현철(Hyunchul Jung) 한국생산제조학회 2010 한국생산제조학회지 Vol.19 No.4

Recently, environment problems have effects on the electronic equipments. Security problems are presented. For security reasons, it is necessary to study electronic equipments. In this paper, we handle the Elasticity modulus on the polymer insulator by UV irradiation. The types of material are used in this experiment, is the EPDM (Ethylene Propylene Diene Monomer). For increasing the reliability, real material specimens are used. For this study, we used ESPI (Electronic speckle pattern interferometry), UTM (Universal thesting machine) device, Accelerated weathering tester. Through this measurement, we evaluated how much UV irradiation has effect on polymer insulator and how long does it take to change the polymer insulator. Also this paper will give a help in electronic industry and the method of measuring the insulator elasticity modulus of polymer could be utilized in life estimation and replacement time of the products of electronic equipment that is used in real industrial fields.

인장 속도에 따른 포아송비의 변화

김동수(Dongsoo Kim),정현철(Hyunchul Jung),장호섭(Hosub Chang),김경석(Kyeongsuk Kim) 한국생산제조학회 2010 한국생산제조시스템학회 학술발표대회 논문집 Vol.2010 No.10

This study shows the variation of poisson’s ratio acoording to tensile speed by UTM(Unversal Testing Machine). To make a experiment, used CCD cameras and measured a volume change at real-time. According to tensile speed consider the change of the Poisson’s ratio, Confirmed the functional relation of the Poisson’s ratio which follows in tensile speed. Generally Poisson’s ratio has been consider as one of properties, but the test result shows Poisson’s ratio changed by external conditions(Tensile speed). And Poisson’s ratio increase in Fracture zone.