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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 23, Issue 6 - Dec 2003
Volume 23, Issue 5 - Oct 2003
Volume 23, Issue 4 - Aug 2003
Volume 23, Issue 3 - Jun 2003
Volume 23, Issue 2 - Apr 2003
Volume 23, Issue 1 - Feb 2003
Selecting the target year
Dielectric Cure Monitoring of Thermosetting Matrix Composites
Kim, Hyoung-Geun ; Lee, Dai-Gil ;
Journal of the Korean Society for Nondestructive Testing, volume 23, issue 5, 2003, Pages 409~417
Cure monitoring can be used to improve the quality and productivity of thermosetting resin matrix composite products during their manufacturing process. In this work, the sensitivity of dielectrometry was improved by adequate separation the efforts of sensor and externals on the measured signal. A new algorithm to obtain the degree of cure during dielectric cure monitoring of glass/polyester and glass/epoxy composites was developed by employing a function of both temperature and dissipation factor, in which five cure monitoring parameters were used to calculate the degree of cure. The decreasing pattern of dissipation factor was compared with the relationships between the degree of cure and the resin viscosity. The developed algorithm might be employed for the in situ cure monitoring of thermosetting resin composites.
Nondestructive Interfacial Evaluation and fiber fracture Source Location of Single-Fiber/Epoxy Composite using Micromechanical Technique and Acoustic Emission
Park, Joung-Man ; Kong, Jin-Woo ; Kim, Dae-Sik ; Yoon, Dong-Jin ;
Journal of the Korean Society for Nondestructive Testing, volume 23, issue 5, 2003, Pages 418~428
Fiber fracture is one of the dominant failure phenomena affecting the total mechanical Performance of the composites. Fiber fracture locations were measured through the conventional optical microscope and the nondestructive acoustic emission (AE) technique and then were compared together as a function of the epoxy matrix modulus and the fiber surface treatment by the electrodeposition method (ED). Interfacial shear strength (IFSS) was measured using tensile fragmentation test in combination of AE method. ED treatment of the fiber surface enlarged the number of fiber fracture locations in comparison to the untreated case. The number of fiber fracture events measured by the AE method was less than optically obtained one. However, fiber fracture locations determined by AE detection corresponded with those by optical observation with small errors. The source location of fiber breaks by AE analysis could be a nondestructive, valuable method to measure interfacial shear strength (IFSS) of matrix in non-, semi- and/or transparent polymer composites.
fiber Orientation Effects on the Acoustic Emission Characteristics of Class fiber-Reinforced Composite Materials
Kim, Jung-Hyun ; Woo, Sung-Choong ; Choi, Nak-Sam ;
Journal of the Korean Society for Nondestructive Testing, volume 23, issue 5, 2003, Pages 429~438
The effects of fiber orientation on acoustic emission(AE) characteristics have been studied for the unidirectional and satin-weave, continuous glass-fiber reinforced plastic(UD-GFRP and SW-GFRP) tensile specimens. Reflection and transmission optical microscopy was used for investigation of the damage zone of specimens. AE signals were classified as different types by using short time fourier transform(STFT) : AE signals with high intensity and high frequency band were due to fiber fracture, while weak AE signals with low frequency band were due to matrix and interfacial cracking. The feature in the rate of hit-events having high amplitudes showed a process of fiber breakages, which expressed the characteristic fracture processes of individual fiber-reinforced plastics with different fiber orientations and with different notching directions. As a consequence, the fracture behavior of the continuous GFRP could be monitored as nondestructive evaluation(NDE) through the AE technique.
Acoustic Emission Source Location in Filament Wound CFRP Pressure Vessel
Kim, Jeong-Kon ; Won, Yong-Gu ; Kwon, Oh-Yang ;
Journal of the Korean Society for Nondestructive Testing, volume 23, issue 5, 2003, Pages 439~444
Acoustic emission(AE) ran be very effectively applied to locate the damaged area in large structures by detecting the elastic waves generated during the damage process within solids. Source location in the composite structures has been, however, extremely difficult due to the acoustic anisotropy with the velocity dependence on fiber orientations. In this study, it has been shown that a newly proposed method for 2-D source location of anisotropic structures is practically applicable to the real structure. The method employes wave velocities obtained with different velocities from
for a filament wound composite pressure vessel under the air-filled and the water-filled conditions.
Health Monitoring in Composite Structures using Piezoceramic and fiber Optic Sensors
Kim, C.G. ; Sung, D.U. ; Kim, D.H. ; Bang, H.J. ;
Journal of the Korean Society for Nondestructive Testing, volume 23, issue 5, 2003, Pages 445~454
Health monitoring is a major concern not only in the design and manufacturing but also in service stages for composite laminated structures. Excessive loads or low velocity impact can cause matrix cracks and delaminations that may severely degrade the load carrying capability of the composite laminated structures. To develop the health monitoring techniques providing on-line diagnostics of smart composite structures can be helpful in keeping the composite structures sound during their service. In this study, we discuss the signal processing techniques and some applications for health monitoring of composite structures using piezoceramic sensors and fiber optic sensors.
Multi-Stage Adaptive Noise Cancellation Technique for Synthetic
Kim, Jae-Joon ;
Journal of the Korean Society for Nondestructive Testing, volume 23, issue 5, 2003, Pages 455~463
Adaptive noise cancellation techniques are ideally suitable for reducing spatially varying noise due to the grain structure of material in ultrasonic nondestructive evaluation. Grain noises have an un-correlation property, while flaw echoes are correlated. Thus, adaptive filtering algorithms use the correlation properties of signals to enhance the signal-to-noise ratio (SNR) of the output signal. In this paper, a multi-stage adaptive noise cancellation (MANC) method using adaptive least mean square error (LMSE) filter for enhancing flaw detection in ultrasonic signals is proposed.
Three-Dimensional Processing of Ultrasonic Pulse-Echo Signal
Song, Moon-Ho ; Song, Sang-Rock ; Cho, Jung-Ho ; Sung, Je-Joong ; Ahn, Hyung-Keun ; Jang, Soon-Jae ;
Journal of the Korean Society for Nondestructive Testing, volume 23, issue 5, 2003, Pages 464~474
Ultrasonic imaging of 3-D structures for nondestructive evaluation must provide readily recognizable images with enough details to clearly show various flaws that may or may not be present. Typical flaws that need to be detected are miniature cracks, for instance, in metal pipes having aged over years of operation in nuclear power plants; and these sub-millimeter cracks or flaws must be depicted in the final 3-D image for a meaningful evaluation. As a step towards improving conspicuity and thus detection of flaws, we propose a pulse-echo ultrasonic imaging technique to generate various 3-D views of the 3-D object under evaluation through strategic scanning and processing of the pulse-echo data. We employ a 2-D Wiener filter that filters the pulse-echo data along the plane orthogonal to the beam propagation so that ultrasonic beams can be sharpened. This three-dimensional processing and display coupled with 3-D manipulation capabilities by which users are able to pan and rotate the 3-D structure improve conspicuity of flaws. Providing such manipulation operations allow a clear depiction of the size and the location of various flaws in 3-D.
A Study of the Acoustic Microscope System by Large Aperture Probe
Cho, Yong-Sang ; Kim, Jae-Hoon ;
Journal of the Korean Society for Nondestructive Testing, volume 23, issue 5, 2003, Pages 475~479
Traditional ultrasonic evaluation to detect micro/small surface cracks is the pulse-echo technique using the normal immersion transducer with high frequency, or the angle beam transducer with surface wave. It is difficult to make the automatic ultrasonic system that is to detect micro and small surface crack and position on the large structure like steel and ceramic rolls, because of the huge data of inspection and the ambiguous position data of transducer. The aim of this study using the high precision scanning acoustic microscope with 10MHz large aperture transducer was to display the real time A, B, C-scan for the automatic ultrasonic system in order to detect the existence and position of surface crack. The ultrasonic method with large aperture transducer was improved the scanning time and speed over 10times faster than traditional methods.
Signal Characteristics of Acoustic Emission from Angiosperm and Gymnosperm by the Water Stress
Nam, Ki-Woo ;
Journal of the Korean Society for Nondestructive Testing, volume 23, issue 5, 2003, Pages 480~487
To improve environmental control in various plants, signal characteristics of plants have been studied by a nondestructive technique. In this paper, the acoustic emission (AE) from plants was analyzed for water stress dependency. AE signals were taken from gymnosperm and angiosperm. AE sensor detected AE signals from the plant stem underneath the plant surface below the sensor. AE hit-event counts in daytime were more than those in night time, and it was found that the daily hit counts pattern was strongly affected by the water stress in the plant. frequency bands of AE signals from the angiosperm was different from those from the gymnosperm. Frequency bands of AE in outdoor condition were in accord with those in indoor having similar conditions
Interpretation of AE Signals from Rocket Motor Case Assembly
Rhee, Sang-Ho ; Hwang, Tae-Kyong ; Mun, Sun-Il ;
Journal of the Korean Society for Nondestructive Testing, volume 23, issue 5, 2003, Pages 488~496
To establish nondestructive test method for rocket motor assembly with rubber and aerospace composite materials, practicable quality control acoustic emission test method is presented. Structural analysis for motor assembly is performed by ABAQUS code and analysis output result is confirmed by strain gage and AE data. Various specimens were tested and analyzed using strain gage and acoustic emission data. The hit rate of acoustic emission was closely related with case/rubber debonding. This report also describes practicable acoustic emission nondestructive method for evaluating motor case assembly quality assurance in the industrial field.
NDE for Realising Better Quality of Life in the Context of INDIA - An Emerging Economy
Raj, Baldev ;
Journal of the Korean Society for Nondestructive Testing, volume 23, issue 5, 2003, Pages 497~519
Science and technology is an essential ingredient of the progress in modern society. Measurements enable action and actions enable results. Non-Destructive Evaluation (NDE) - the science and technology of measurements without affecting the Properties and performance of the test object is an interdisciplinary domain area of high significance far ensuring quality, productivity and safety thus enabling better qualify of lift to the inhabitants on this planet. The test object can be material, component, plant, earth, environment etc. Total qualify management, total productivity management, concurrent engineering and many other essential ingredients of success in plant engineering and manufacturing industry are dependent on NDE far success and good returns on investments.
Remote NDT for Inspection of Reactor Vessel Components of fast Breeder Test Reactor
Anandapadmanaban, B. ; Srinivasan, G. ; Kapoor, R.P. ;
Journal of the Korean Society for Nondestructive Testing, volume 23, issue 5, 2003, Pages 520~525
Fast Breeder Test Reactor (FBTR) is a 40MW (thermal) / 13.2MW (electrical), Plutonium - Uranium mixed carbide fuelled, sodium cooled, loop type nuclear reactor operating at Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam. Its main aim is to generate experience in operation of fast reactors and sodium systems and to serve as an irradiation facility for development of fuels and structural materials fur fast reactors. Nuclear reactors pose difficulties to the NDT techniques used to monitor the conditions of the internal components. Sodium cooled fast breeder reactors have their own typical difficulties in using the NDT techniques. These are due to the need for operation in aggressive environment of nuclear radiation and sodium (molten/vapour), as well as the need to maintain leak tightness of a very high order during all states of reactor operation and shutdown for fuel handling, maintenance and remote inspection. This paper discusses the following NDT techniques, which have been successfully used for the past 15 years in FBTR: (i) Periscope and Projector, (ii) Core Co-ordinate Measuring Device and, (iii) Optical fiberscope. The inspection using these techniques have given confidence for further reactor operation at high power by giving useful data on the conditions of the components inside the reactor vessel.
Impact-Resonance Testing of Concrete Structures
Kim, Young-H. ;
Journal of the Korean Society for Nondestructive Testing, volume 23, issue 5, 2003, Pages 526~531
Condition assessment of concrete structures is essential since their performance affects public safety. Impact resonance testing has been widely used for the nondestructive testing of the concrete structures. In this article, the background, basic principles of the impact resonance testing were described. Not only laboratory studies but also the field applications such as basement concrete of large structure and large slurry wall are described.