Go to the main menu
Skip to content
Go to bottom
REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
> Journal Vol & Issue
Journal of the Korean Society for Nondestructive Testing
Journal Basic Information
Journal DOI :
The Korean Society for Nondestructive Testing
Editor in Chief :
Volume & Issues
Volume 22, Issue 6 - Dec 2002
Volume 22, Issue 5 - Oct 2002
Volume 22, Issue 4 - Aug 2002
Volume 22, Issue 3 - Jun 2002
Volume 22, Issue 2 - Apr 2002
Volume 22, Issue 1 - Feb 2002
Selecting the target year
Development and Characterization of High Frequency Ultrasonic Transducer Using PVDF and P(VDF-TrFE)
Kim, Ki-Bok ; Kim, Byoung-Geuk ; Lee, Seung-Seok ;
Journal of the Korean Society for Nondestructive Testing, volume 22, issue 1, 2002, Pages 1~8
The high frequency ultrasonic transducers using polyvinyliden fluoride(PVDF) and polyvinylidene fluoride trifluorethyylene(P(VDF-TrFE)) were developed. The characteristics of fabricated high frequency ultrasonic transducer such as beam diameter, high frequency ultrasonic detection field and amplitude of the first pulse echo signal from the test target in the water were analyzed. The high frequency ultrasonic detection field was affected by the length of coaxial cable between high frequency transducer and ultrasonic pulser/receiver. As the size of the test target increased, the high frequency detection field decreased and the amplitude of a reflection signal increased. The peak amplitude of the first pulse echo signal of P(VDF-TrFE) transducer was higher than that of PVDF transducer. The high frequency ultrasonic detection field of PVDF transducer was wider than that of P(VDF-TrFE) transducer. With C-scan testing, the developed high frequency ultrasonic transducer could detect the 30 to
of hydrogen induced crack of steel specimen by C-scan testing.
Dimensional Measurement of Spent Fuel Assemblies Using Image Processing Technique
Koo, Dae-Seo ; Park, Seong-Won ;
Journal of the Korean Society for Nondestructive Testing, volume 22, issue 1, 2002, Pages 9~13
A pool image processing measurement method has been developed to improve the examination efficiency and to minimize the errors of dimensional measurements of spent fuel assemblies in pool. Diameter and length measurements of mock-up fuel rods using the image processing system are
on the basis of the true value and their maximum errors are within -0.3 and 0.4mm, respectively, According to the result of dimensional measurement of spent fuels in pool, the upper and lower part diameter and mid part diameter of fuel rods of the J44 fuel assembly irradiated for 2 cycles in the Kori-2 nuclear reactor were decreased by about 2.0 and 3.0% in comparison with design values, respectively. The length of fuel rods was elongated by about 0.4%. The change behavior of diameter and length. of fuel rods of the F02 fuel assembly irradiated for 3 cycles in the Kori-1 nuclear reactor showed a trend similar to the results of J44.
Observation of Fatigue Crack Growth Behavior in 1Cr-1Mo-0.25V Steel Using Image Processing Technology
Nahm, Seung-Hoon ; Kim, Yong-Il ; Ryu, Dae-Hyun ;
Journal of the Korean Society for Nondestructive Testing, volume 22, issue 1, 2002, Pages 14~21
The development of a new experimental method is required to easily observe the growth behavior of fatigue cracks. To satisfy the requirement, an image processing technique was introduced to fatigue testing. The length of surface fatigue crack could be successfully measured by the image processing system. At first, the image data of cracks were stored into the computer while the cyclic loading was interrupted. After testing, crack length was determined using an image processing software which was developed by authors. Various image processing techniques like a block matching method was applied tc the detection of surface fatigue cracks. By comparing the data measured by the image processing system with those by the manual measurement with a microscope, the effectiveness of the image processing system was established. If the proposed method is used to monitor and observe the crack growth behavior automatically, the time and efforts for fatigue test could be dramatically reduced.
A Study on Development of Displacement Measurement System for Structure using a Laser and 2-D Arrayed Photo Sensors
Kang, Moon-Phil ; Lee, Jin-Yi ; Kim, Min-Soo ; Kim, Dae-Jung ; Choe, Won-Ha ; Kang, Ki-Hun ; Kim, Jong-Soo ; Kim, Hoon ;
Journal of the Korean Society for Nondestructive Testing, volume 22, issue 1, 2002, Pages 22~31
A Safety Monitoring System using a laser and 2-D arrayed photo sensors is developed. To monitor of the deformation and small rotation of structure the developed optical system using 2-D photo sensor array was used to detect the variation of optical orbit of laser which was induced by deformation of the structure. Also, an operating program to manage the system and an algorithm for the data acquisition and the database are introduced. In this study, we demonstrated the capabilities of this system by laboratory experiments before applying the system to the field.
Detection and Evaluation Technique of Hydrogen Attack
Won, Soon-Ho ; Hyun, Yang-Ki ; Lee, Jong-O ; Cho, Kyung-Shik ; Lee, Jae-Do ;
Journal of the Korean Society for Nondestructive Testing, volume 22, issue 1, 2002, Pages 32~37
The presence of hydrogen in industrial plants is a source of damage. Hydrogen attack is one such form of degradation and often causing large tube ruptures that necessitate an immediate shutdown. Hydrogen attack may reduce the fracture toughness as well as the strength of steels. This reduction is caused partially by the presence of cavities and microcracks at the grain boundaries. In the past several techniques have been used with limited results. This paper describes the application of an ultrasonic velocity and attenuation in hydrogen damage. Ultrasonic tests showed a decrease in wave velocity and an increase in attenuation. Such results demonstrate the potential for ultrasonic nondestructive testing to quantify damage. Based on this study, reliable recommendation is suggested to detect hydrogen attack.
Development of MFL Testing System for the Inspection of Storage Tank Floor
Won, Soon-Ho ; Cho, Kyung-Shik ; Lee, Jong-O ; Chang, Hong-Keun ; Joo, Gwang-Tae ;
Journal of the Korean Society for Nondestructive Testing, volume 22, issue 1, 2002, Pages 38~44
MFL method is a qualitative inspection tool and is a reliable, fast and economical NDT method. The application of MFL method to the inspection of storage tank floor plates has been shown to be a viable means. Examination of tank floors previously depended primarily upon ultrasonic test methods that required slow and painstaking application. Therefor most ultrasonic inspection of storage tank has been limited to spot testing only. Our NDE group have developed magnetic flux leakage system to overcome limitation of ultrasonic test. The developed system consists of magnetic yoke, array sensor, crawler and software. It is proved that the system is able to detect artificial flaw like 3.2mm diameter, 1.2mm depth in 6mm thick steel plate.
AE Characteristics on the Damage Behavior of TiNi/A16061 Shape Memory Alloy Composites at High Temperature
Lee, Jin-Kyung ; Park, Young-Chul ; Ku, Hoo-Taek ;
Journal of the Korean Society for Nondestructive Testing, volume 22, issue 1, 2002, Pages 45~52
It has been known that tensile residual stresses occurring by the thermal expansion coefficient mismatch between fiber and matrix is a cause of the weak strength of metal matrix composites(MMCs). In order to solve this problem, TiNi alloy fiber was used as a reinforced material in TiNi/A16001 shape memory alloy composite in this study. TiNi alloy fiber improves the tensile strength of the composite by causing compressive residual stress in matrix on the basis of its shape memory effect. Pre-strain was imposed to generate the compressive residual stresses inside the TiNi/A16001 shape memory alloy composites. AE technique was used to quantify the microscopic damage behavior of the composite at high temperature. The effect of applied pre-strains on the AE behavior was also evaluated.
A Study on the Non-Contact Detection Technique of Defects Using AC Current - The Influence of Frequency and lift-off -
Kim, Hoon ; Na, Eu-Gyun ;
Journal of the Korean Society for Nondestructive Testing, volume 22, issue 1, 2002, Pages 53~58
New nondestructive inspection (NDI) technique to detect the defect in metal was developed in which an electromagnetic field is induced in a metal by AC current flowing in the magnetic coil and the leak magnetic-flux disturbed by defects is measured using a tape-recorder head with air gap. This technique can be applied in evaluating the location and sizing of surface defects in components of the ferromagnetic body by means of the non-contacting measurement. In this paper, we have applied this technique to the evaluation of two-dimensional surface cracks in ferromagnetic metal, and also investigated the influence of the various frequencies and lift-off. Defects were detected with maximum values in the distribution of voltage and it was found that the maximum values tend to increase with the defect depth. Although the maximum values for defects are affected by the frequency and lift-off, the depth of small defects can be estimated from the linear relationship between the depth and voltage rate
A FEM Analysis of Remote Field Eddy Current Distribution Characteristics to CANDU Fuel Channel Tube(I)
Huh, Hyung ; Chung, Hyun-Kyu ; Kim, Kern-Jung ;
Journal of the Korean Society for Nondestructive Testing, volume 22, issue 1, 2002, Pages 59~64
A FEM model of the remote-field eddy current effect is presented for zirconium-2.5 percent niobium(Zr-2.5%Nb) nuclear reactor pressure tubes to demonstrate the important electromagnetic field phenomena. This model is applied to evaluate the optimal operating frequency and detector position. There are many ambiguous experimental results connected with this technique. Finite element calculations can be used in the interpretation of these experimental results even though the electromagnetic fields measured in the remote-field technique are very small.
Evaluation of Aging Degradation in 2.25Cr-1Mo Steel by Coercivity and Remanence Measurements - Microstructural Approach
Byeon, Jai-Won ; Kwun, Sook-In ;
Journal of the Korean Society for Nondestructive Testing, volume 22, issue 1, 2002, Pages 65~73
Artificial aging was performed to simulate the microstructural degradation in 2.25Cr-1Mo steel arising from long time exposure at
. Microstructural analysis (mean equivalent size, number of carbides per unit area) and measurement of mechanical properties(UTS, Vickers hardness) and magnetic properties(coercivity, remanence) were performed. By comparing these results, the relationship between magnetic properties and microstructural changes with artificial aging was clarified. The carbides were classified as rod, globular and acicular type in terms of morphology. The fine acicular carbides were found to diminish drastically in the initial stage of aging. The magnetic coercivity and remanence were observed to decrease rapidly in the initial about 920 hours of aging time and then decrease slowly afterwards. Linear correlations between the mechanical properties and magnetic properties such as correlations remanence were found.
Understanding of Laser-based Ultrasonics
Lee, Seung-Seok ; Jang, Tae-Seong ;
Journal of the Korean Society for Nondestructive Testing, volume 22, issue 1, 2002, Pages 74~87