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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Nondestructive Testing
Journal Basic Information
Journal DOI :
The Korean Society for Nondestructive Testing
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Volume & Issues
Volume 30, Issue 6 - Dec 2010
Volume 30, Issue 5 - Oct 2010
Volume 30, Issue 4 - Aug 2010
Volume 30, Issue 3 - Jun 2010
Volume 30, Issue 2 - Apr 2010
Volume 30, Issue 1 - Feb 2010
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Defect Detection of the Wall Thinning Pipe of the Nuclear Power Plant Using Infrared Thermography
Kim, Kyeong-Suk ; Chang, Ho-Sub ; Hong, Dong-Pyo ; Park, Chan-Joo ; Na, Sung-Won ; Kim, Kyung-Su ; Jung, Hyun-Chul ;
Journal of the Korean Society for Nondestructive Testing, volume 30, issue 2, 2010, Pages 85~90
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-destrnctive 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.
Shearing Phase Lock-in Infrared Thermography for Defects Evaluation of Metallic Materials Specimen
Park, Jeong-Hak ; Choi, Man-Yong ; Kim, Won-Tae ;
Journal of the Korean Society for Nondestructive Testing, volume 30, issue 2, 2010, Pages 91~97
This paper proposes method to evaluate the location and size of the internal defects of metallic specimens by the shearing phase lock-in infrared thermography. Until now, infrared thermography test for metal specimen of STS304 and Cu-Zn were conducted to find the best test conditions. However, In unspecified situation of the form and existence of defects, there was a disadvantage to takes a long time for finding the optimal experimental conditions. The defect detection and evaluation was performed at 60 MHz signal using lock-in and shearing-phase method under limited heating conditions. By shearing-phase distribution method, Defects for the maximum, minimum and zero points were quantitatively detected at the size and location of the subsurface. As results, application of the proposed technique was verified for STS304 and Cu7-Zn3 with artificial defect and factors affected defect evaluation were searched and analyzed.
Panorama Image Processing for Condition Monitoring with Thermography in Power Plant
Jeon, Byoung-Joon ; Kim, Tae-Hwan ; Kim, Soon-Geol ; Mo, Yoon-Syub ; Kim, Won-Tae ;
Journal of the Korean Society for Nondestructive Testing, volume 30, issue 2, 2010, Pages 98~103
In this paper, imaging processing study obtained from CCD image and thermography image was performed in order to treat easily thermographic data without any risks of personnels who conduct the condition monitoring for the abnormal or failure status occurrable in industrial power plants. This imaging processing is also applicable to the predictive maintenance. For confirming the broad monitoring, a methodology producting single image from the panorama technique was developed no matter how many cameras are employed, including fusion method for discrete configuration for the target. As results, image fusion from quick realtime processing was obtained and it was possible to save time to track the location monitoring in matching the images between CCTV and thermography.
Defects Evaluation at Lap Joint Friction Stir Welding by Lock-in Ultrasound Infrared Thermography
Choi, Man-Yong ; Park, Hee-Sang ; Park, Jeong-Hak ; Kang, Ki-Soo ;
Journal of the Korean Society for Nondestructive Testing, volume 30, issue 2, 2010, Pages 104~109
Lap joint friction stir welding(LFSW) is an relatively new solid state joining process. A6061-T6 aluminium alloy has gathered wide acceptance in the fabrication of light weight structures requiring a high strength to weight ratio and good corrosion resistance. Test methods used in this paper, lock-in thermography, a phase difference between the defect area and the healthy area indicates the qualitative location and size of the defect. In this paper, the defects detected from the thermal image of mechanical properties for weld were evaluated and compared by the lock-in infrared thermography technique.
A Study on the Leakage Evaluation for Power Plant Valve Using Infrared Thermography Method
Lee, Sang-Guk ;
Journal of the Korean Society for Nondestructive Testing, volume 30, issue 2, 2010, Pages 110~115
This study was conducted to estimate the feasibility using thermal image measurement that is applicable to internal leak diagnosis for the power plant valve. Abnormal heating of valve surface associated with high temperature steam f10w toward valve outlet side in the condition of low temperature is a primary indicator of leakage problems in high temperature and pressure valves. Thermal imaging enables to see the invisible thermal radiation that may portend impending damage before their condition becomes critical. When steam flow in valve outlet side in the condition of low temperature is converted into heat transmitted through the valve body due to the internal leakage in valve. The existence of abnormally increasable leakage rate in the valve will result in abnormally high levels of heat to be generated that can be quickly identified with a thermal image avoiding energy loss or damage of valve component. From the experimental results, it was suggested that the thermal image measurement could be an effective way to precisely diagnose and evaluate internal leak situation of valve.
Infrared Thermographic Monitoring for Failure Characterization in Railway Axle Materials
Kim, Jeong-Guk ;
Journal of the Korean Society for Nondestructive Testing, volume 30, issue 2, 2010, Pages 116~120
The wheelset, an assembly of wheel and axle, is one of important parts in railway bogie, directly related with the running safety of railway rolling stock. In this investigation, the tensile failure behavior of railway axle materials was investigated. The tensile coupons were prepared from the actual rolling stock parts, which were operated over 20 years. The tensile testing was performed according to the KS guideline. During tensile testing, an infrared camera was employed to monitor temperature changes in specimen as well as demonstrate temperature contour in terms of infrared thermographic images. The thermographic images of tensile specimens showed comparable results with mechanical behavior of tensile materials. In this paper, the failure mode and behavior of railway axle materials were provided with the aid of infrared thermography technique.
Condition Monitoring under In-situ Lubrication Status of Bearing Using Infrared Thermography
Kim, Dong-Yeon ; Hong, Dong-Pyo ; Yu, Chung-Hwan ; Kim, Won-Tae ;
Journal of the Korean Society for Nondestructive Testing, volume 30, issue 2, 2010, Pages 121~125
The infrared thermography technology rather than traditional nondestructive methods has benefits with non-contact and non-destructive testings in measuring for the fault diagnosis of the rotating machine. In this work, condition monitoring measurements using this advantage of thermography were proposed. From this study, the novel approach for the damage detection of a rotating machine was conducted based on the spectrum analysis. As results, by adopting the ball bearing used in the rotating machine applied extensively, an spectrum analysis with thermal imaging experiment was performed. Also, as analysing the temperature characteristics obtained from the infrared thermography for in-situ rotating ball bearing under the lubrication condition, it was concluded that infrared thermography for condition monitoring in the rotating machine at real time could be utilized in many industrial fields.
Evaluation of Composite Laminates for Aircraft Primary-Structure Applications Using Non-Linear Parameter of Ultrasonic Guided Wave
Cho, Youn-Ho ; Kim, Do-Youn ; Choi, Heung-Soap ; Lee, Joon-Hyun ;
Journal of the Korean Society for Nondestructive Testing, volume 30, issue 2, 2010, Pages 126~131
The purpose of this study is to assess the condition of composites used in aircraft under varying temperature environment with ultrasound guided wave technique. Investigation of crucial influential factor on the composite health monitoring related to aircraft operational environments such as the number of thermal cycles and temperature deviation between ground level and flight altitude has been of a great concern for aircraft safety issue. In this study, ultrasonic guided wave health monitoring scheme is proposed to evaluate composite specimens damaged with the thermal fatigue simulating aircraft operational condition. Guided wave dispersion curves are used to select right modes which show a promising sensitivity to each different thermal fatigue damage level. The present approach can be also implemented as one of on-lines health monitoring tools for aircraft.
Vibro-Contact Analysis of Ultrasonic Atomic Force Microscopy Tip and It's Application to Nano Surface
Park, Tae-Sung ; Kwak, Dong-Ryul ; Park, Ik-Keun ; Kim, Chung-Seok ;
Journal of the Korean Society for Nondestructive Testing, volume 30, issue 2, 2010, Pages 132~138
Vibro-contact of cantilever tip is studied with respect to contact mechanics and an elastic characteristic of nanoscale surface is imaged. The contact resonance frequency is calculated theoretically using the spring-mass and Herzian models, and the variation of resonance frequency of cantilever was analyzed when the cantilever was free and contact. The elasticity imaging was also achieved successfully using phase and amplitude signals obtained from the spheroidized steel specimens by prototype ultrasonic AFM.
Bending Fatigue Characterization of Al6061 Alloy by Acoustic Nonlinearity of Narrow Band Laser-Generated Surface Wave
Nam, Tae-Hyung ; Choi, Sung-Ho ; Jhang, Kyung-Young ; Kim, Chung-Seok ; Lee, Tae-Hun ;
Journal of the Korean Society for Nondestructive Testing, volume 30, issue 2, 2010, Pages 139~145
Bending fatigue of aluminium alloy was characterized by acoustic nonlinearity of narrow band laser-generated surface wave. The higher harmonic components generated intrinsically by arrayed line laser beam were analyzed theoretically and acoustic nonlinearity was measured successfully on the surface of fatigue damaged aluminium 6061 alloy. The acoustic nonlinearity increased as a function of fatigue cycles and has close relation with damage level. Consequently, the nonlinear acoustic technique of laser-generated surface wave could be potential to characterize surface damages subjected to fatigue.
Determination of Elastic Modulus of Equal-Channel-Angular-Pressed Aluminum 5052 Alloy by Acoustic Material Signature
Kim, Chung-Seok ; Park, Ik-Keun ; Jhang, Kyoung-Young ; Miyasaka, Chiaki ;
Journal of the Korean Society for Nondestructive Testing, volume 30, issue 2, 2010, Pages 146~154
The effects of severe plastic deformation, equal channel angular pressing, and annealing of Al 5052 alloy on elastic modulus have been studied. The AI 5052 alloy was plastically deformed by ECAP method after solution treatment, and then finally annealing heat treated. Elastic modulus was measured by conventional tensile and nano-indentation test, and also measured on the surface of the specimen using acoustic material signature of the acoustic microscope. The variation in the elastic modulus influenced by plastic deformation and heat treatment, inaccessible by the conventional techniques, was successfully measured by acoustic material signature and obtained the elastic modulus depending on crystal orientation at each grain.
Development of a Multichannel Eddy Current Testing Instrument(I)
Lee, Hee-Jong ; Nam, Min-Woo ; Cho, Chan-Hee ; Yoon, Byung-Sik ; Cho, Hyun-Joon ;
Journal of the Korean Society for Nondestructive Testing, volume 30, issue 2, 2010, Pages 155~161
Recently, the electromagnetic techniques of the eddy current testing(ECT), alternating current field testing, magnetic flux leakage testing and remote field testing have been used as a nondestructive evaluation method based on the electromagnetic induction. The eddy current testing is now widely accepted as a NDE method for the heat exchanger tube in the electric power industry, chemical, shipbuilding, and military. The ECT system mainly consists of the synthesizer module, analog module, analog-to-digital converter, power supplier, and data acquisition and analysis program. In this study, the synthesizer module and the analog module which are essential to the ECT system were primarily developed. The developed ECT system is basically a multifrequency type which is able to inject the maximum four frequencies based on the frequency and time domain multiplexing method. Conclusively, we confirmed that the EC signal was processed appropriately in each circuit modules, and the Lissajous EC signal was displayed in the impedance plane.