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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean Society for Nondestructive Testing
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Journal DOI :
The Korean Society for Nondestructive Testing
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Volume & Issues
Volume 33, Issue 6 - Dec 2013
Volume 33, Issue 5 - Oct 2013
Volume 33, Issue 4 - Aug 2013
Volume 33, Issue 3 - Jun 2013
Volume 33, Issue 2 - Apr 2013
Volume 33, Issue 1 - Feb 2013
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Comparative Study of Linear and Nonlinear Ultrasonic Techniques for Evaluation Thermal Damage of Tube-Like Structures
Li, Weibin ; Cho, Younho ; Li, Xianqiang ;
Journal of the Korean Society for Nondestructive Testing, volume 33, issue 1, 2013, Pages 1~6
DOI : 10.7779/JKSNT.2013.33.1.1
Ultrasonic guided wave techniques have been widely used for long range nondestructive detection in tube-like structures. The present paper investigates the ultrasonic linear and nonlinear parameters for evaluating the thermal damage in aluminum pipe. Specimens were subjected to thermal loading. Flexible polyvinylidene fluoride (PVDF) comb transducers were used to generate and receive the ultrasonic waves. The second harmonic wave generation technique was used to check the material nonlinearity change after different heat loadings. The conventional linear ultrasonic approach based on attenuation was also used to evaluate the thermal damages in specimens. The results show that the proposed experimental setup is viable to assess the thermal damage in an aluminum pipe. The ultrasonic nonlinear parameter is a promising candidate for the prediction of micro-damages in a tube-like structure.
Feasibility Study on Surface Microcrack Detection of the Steel Wire Rods Using Electromagnetic Acoustic Resonance
Heo, Taehoon ; Cho, Seung Hyun ; Ahn, Bongyoung ; Lim, Zhong Soo ;
Journal of the Korean Society for Nondestructive Testing, volume 33, issue 1, 2013, Pages 7~13
DOI : 10.7779/JKSNT.2013.33.1.7
The surface microcrack over a few tens of micrometers is one of severe problems of a steel wire rod to lead to the failure of the final products, so the method to evaluate crack depth has been required to develop. This work investigates the feasibility of electromagnetic acoustic resonance (EMAR) for this problem. EMAR is the method for measurement of resonant features using electromagnetic acoustic transducer (EMAT). Generally, EMAR is sensitive to small variation of the structures and easy to apply it to the industrial field because of the feature of noncontact measurement. Through several EMAR experiments, the change of the resonant frequencies and attenuation in reverberation has been observed. The results confirms that the surface cracks of around 100 micrometer depth can be detected successfully with the present method.
Measurement of Ultrasonic Nonlinearity Parameter of Fused Silica and Al2024-T4
Kang, To ; Lee, Taekgyu ; Song, Sung-Jin ; Kim, Hak-Joon ;
Journal of the Korean Society for Nondestructive Testing, volume 33, issue 1, 2013, Pages 14~19
DOI : 10.7779/JKSNT.2012.33.1.14
Nonlinearity parameter is an inherent property of materials measuring fundamental acoustic amplitude(
) and second harmonic amplitude(
). However, measurement of
has complex calibration procedure, many researchers prefer to measure relative nonlinearity parameter rather than absolute nonlinearity parameter. But, relative nonlinearity parameter is only detect materials degradation with various degradation samples, it is limited application in determining third order elastic constants of materials. Therefore, in this study, the piezoelectric detection method is adopted to measure absolute nonlinearity parameter due to experimental simplicity compare to capacitive detector. Linearity of measurement system is verified by
plot, and we measured ultrasonic nonlinearity parameters of fused silica and Al2024-T4.
Degradation Assessment of Aluminum Alloy 6061-T6 Using Ultrasonic Attenuation Measurements
Kim, Hun-Hee ; Kang, To ; Seo, Mu-Kyung ; Song, Sung-Jin ; Kim, Hak-Joon ; Kim, Kyung-Cho ; Kim, Young-Bum ;
Journal of the Korean Society for Nondestructive Testing, volume 33, issue 1, 2013, Pages 20~25
DOI : 10.7779/JKSNT.2013.33.1.20
Ultrasonic methods are widely used to degradation assessment. Remaining-life cycle of metal can be estimated by ultrasonic parameters because ultrasonic velocity and attenuation are affected by change of material properties with accumulated fatigue in the metal. Therefore, in this study, we will estimate overall change of material properties by 2D C-scan image. Fatigued aluminum alloy 6061-T6 samples from 0 to 85% were prepared for evaluating fatigue life cycle. Also, degraded image of materials using attenuation is proposed to estimate degree of material degradation for determining degraded area of fatigued samples. Finally, we will predicts process pf degradation with measured attenuation of fatigued aluminum alloy 6061-T6 samples.
Development of Automated Nondestructive Inspection System for BMI Nozzles in Nuclear Vessel
Park, Joon Soo ; Lee, Won Kun ; Han, Won Jin ; Lee, Sun Ho ; Seong, Un Hak ;
Journal of the Korean Society for Nondestructive Testing, volume 33, issue 1, 2013, Pages 26~33
DOI : 10.7779/JKSNT.2013.33.1.26
BMI nozzles in bottom head of the nuclear vessel are one of major components in nuclear power plants. The BMI nozzles have high possibility to generate PWSCC(primary water stress corrosion crack) according to recent foreign case although operation temperature is lower then the upper head of the nuclear vessel. Thus, nondestructive inspection of the BMI nozzles is required. But, inspection of BMI nozzles is not easy since the BMI nozzles placed in high radiated area and inside the nozzles filled with boric acid. Thus, in this study, a TOFD transducer for inspection of BMI and automated scanner system with water were developed. Also, validation of performance of the developed transducer and system are performed using specimens with artificial defects.
Application Defects Detection in the Small-Bore Pipe Using Infrared Thermography Technique
Yun, Kyung-Won ; Kim, Dong-Lyul ; Jung, Hyun-Chul ; Hong, Dong-Pyo ; Kim, Kyeong-Suk ;
Journal of the Korean Society for Nondestructive Testing, volume 33, issue 1, 2013, Pages 34~39
DOI : 10.7779/JKSNT.2013.33.1.34
In the advanced research deducted infrared thermography (IRT) test using 4 inch pipe with artificial wall-thinning defect to measure on the wall-thinned nuclear pipe components. This study conducted for defect detection condition of nuclear small-bore pipe research using deducted condition in the advanced research. Defect process is processed by change for defect length, circumferential direction angle, wall-thinning depth. In the used equipment IR camera and two halogen lamps, whose full power capacitany is 1 kW, halogen lamps and Target pipe experiment performed to the distance of the changed 1 m, 1.5 m, 2 m. To analysis of the experimental results ensure for the temperature distribution data, by this data measure for defect length. artificial defect of 4 inch pipe is high reliability in the 2 m, but small-bore pipe is in the 1.5 m from the defect clearly was detected.
NDE of the Internal Hole Defect of Dental Composite Restoration Using Infrared Lock-In Thermography
Gu, Ja-Uk ; Choi, Nak-Sam ;
Journal of the Korean Society for Nondestructive Testing, volume 33, issue 1, 2013, Pages 40~45
DOI : 10.7779/JKSNT.2013.33.1.40
The purpose of this study was to detect the pin hole defect of dental composite restoration using lock-in thermography method. Amplitude and phase images of the composite resin specimens were analyzed according to the lock-in frequency and the diameter of defect area. Through the amplitude image analysis, at lock-in frequency of 0.05 Hz, defect diameters 2-5 mm exhibited the highest amplitude contrast value between defective area and sound area. The lock-in frequency range of 0.3-0.5 Hz provided good phase angle contrast for the defect area. At lock-in frequency range of 0.5 Hz, defect diameter of 5 mm exhibited the highest phase contrast value. It is concluded that the infrared lock-in thermography method verified the effectiveness for detecting the pin hole defect of dental composite restoration.
Influence of Compressive Stress in TGO Layer on Impedance Spectroscopy from TBC Coatings
Kang, To ; Zhang, Jianhai ; Yuan, Maodan ; Song, Sung-Jin ; Kim, Hak-Joon ; Kim, Yongseok ; Seok, Chang Sung ;
Journal of the Korean Society for Nondestructive Testing, volume 33, issue 1, 2013, Pages 46~53
DOI : 10.7779/JKSNT.2013.33.1.46
Impedance spectroscopy is a non-destructive evaluation (NDE) method first proposed and developed for evaluating TGO layers with compressive stress inside thermally degraded plasma-sprayed thermal barrier coatings (PS TBCs). A bode plot (phase angle (h) vs. frequency (f)) was used to investigate the TGO layer on electrical responses. In our experimental study, the phase angle of Bode plots is sensitive for detecting TGO layers while applying compressive stress on thermal barrier coatings. It is difficult to detect TGO layers in samples isothermally aged for 100 hrs and 200 hrs without compressive stress, and substantial change of phase was observed these samples with compressive stress. Also, the frequency shift of the phase angle and change of the phase angle are observed in samples isothermally aged for more than 400 hrs.
Analysis of Acoustic Reflectors for SAW Temperature Sensor and Wireless Measurement of Temperature
Kim, Ki-Bok ; Kim, Seong-Hoon ; Jeong, Jae-Kee ; Shin, Beom-Soo ;
Journal of the Korean Society for Nondestructive Testing, volume 33, issue 1, 2013, Pages 54~62
DOI : 10.7779/JKSNT.2013.33.1.54
In this study, a wireless and non-power SAW (surface acoustic wave) temperature sensor was developed. The single inter-digital transducer (IDT) of SAW temperature sensor of which resonance frequency is 434 MHz was fabricated on
piezoelectric substrate by semiconductor processing technology. To find optimal acoustic reflector for SAW temperature sensor, various kinds of acoustic reflectors were fabricated and their reflection characteristics were analyzed. The IDT type acoustic reflector showed better reflection characteristic than other reflectors. The wireless temperature sensing system consisting of SAW temperature sensor with dipole antenna and a microprocessor based control circuit with dipole antenna for transmitting signal to activate the SAW temperature sensor and receiving the signal from SAW temperature sensor was developed. The result with wireless SAW temperature sensing system showed that the frequency of SAW temperature sensor was linearly decreased with the increase of temperature in the range of 40 to
and the developed wireless SAW temperature sensing system showed the excellent performance with the coefficient of determination of 0.99.
Implementation Status of Performance Demonstration Program for Steam Generator Tubing Analysts in Korea
Cho, Chan-Hee ; Lee, Hee-Jong ; Yoo, Hyun-Ju ; Nam, Min-Woo ; Hong, Sung-Yull ;
Journal of the Korean Society for Nondestructive Testing, volume 33, issue 1, 2013, Pages 63~68
DOI : 10.7779/JKSNT.2013.33.1.63
Some essential components in nuclear power plants are periodically inspected using non-destructive examinations, for example ultrasonic, eddy current and radiographic examinations, in order to determine their integrity. These components include nuclear power plant items such as vessels, containments, piping systems, pumps, valves, tubes and core support structure. Steam generator tubes have an important safety role because they constitute one of the primary barriers between the radioactive and non-radioactive sides of the nuclear power plant. There is potential that if a tube bursts while a plant is operating, radioactivity from the primary coolant system could escape directly to the atmosphere. Therefore, in-service inspections are critical in maintaining steam generator tube integrity. In general, the eddy current testing is widely used for the inspection of steam generator tubes due to its high inspection speed and flaw detectability on non-magnetic tubes. However, it is not easy to analyze correctly eddy current signals because they are influenced by many factors. Therefore, the performance of eddy current data analysts for steam generator tubing should be demonstrated comprehensively. In Korea, the performance of steam generator tubing analysts has been demonstrated using the Qualified Data Analyst program. This paper describes the performance demonstration program for steam generator tubing analysts and its implementation results in Korea. The pass rate of domestic analysts for this program was 71.4%.
Realtime Identification of the Propagation Direction of Received Echoes in Long-Range Ultrasonic Testing
Choi, Myoung Seon ; Heo, Won Nyoung ;
Journal of the Korean Society for Nondestructive Testing, volume 33, issue 1, 2013, Pages 69~72
DOI : 10.7779/JKSNT.2013.33.1.69
In long-range ultrasonic testing, a phased array probe composed of multiple identical transducers with an uniform interval of one quarter wavelength is usually used for the transmission or reception directivity control. This paper shows that the propagation directions of individual echoes can be identified in real time by displaying the inputs of a process for summing the constitution reception signals after compensating the phase difference due to the transducer interval, together with the output of the process. A constructive interference of the constitution echoes indicates a forward direction echo propagating along an intended direction while a destructive interference implies a reverse direction echo propagating along the direction opposite to the intended one.
Roughness Measurement of Hole Processing Surface for Mold Steel Using White Light Interferometer
Lee, Seung-Chul ; Kim, Kyeong-Suk ;
Journal of the Korean Society for Nondestructive Testing, volume 33, issue 1, 2013, Pages 73~79
DOI : 10.7779/JKSNT.2013.33.1.73
In this study, NIMAX material has been processed using the three-dimensional measuring instrument and white light interferometer. they were tested to roundness and surface roughness and results are as follows: As for a cutting characteristic, it indicated that F4 showed a lower result than 2F showed due to the high hardness of the material and showed a good result when spindle rotation speed and tool feed were low. As for the measurement of roundness through 3-Dimensional measuring machine, it indicated that 4F showed a good result like the condition of cutting component and that roundness showed a good result when spindle rotation speed of 1,700 rpm and tool feed speed of 85 mm/min were applied. As for the surface roughness of processing surface, Surface roughness showed better 4F than 2F and conditions of spindle rotation speed 1,700 rpm, tool feed rate 55 mm/min showed good results in the Ra
Ahn, HeeSung ;
Journal of the Korean Society for Nondestructive Testing, volume 33, issue 1, 2013, Pages 80~95
Nondestructive Evaluation Technique for Continuum Structures Using Non-Contact Magnetic Flux Leakage(MFL) Measurement
Park, Seunghee ;
Journal of the Korean Society for Nondestructive Testing, volume 33, issue 1, 2013, Pages 96~101