scholarly journals Nedestruktivní zkoušení trubek pomocí metody LFET, UT a ET / Nondestructive testing of tubes using the LFET, UT and ET methods

2015 ◽  
Vol 59 (3) ◽  
pp. 77-80
Author(s):  
M. Mráz
Keyword(s):  
Nondestructive Testing ◽  
Ultrasonic Testing ◽  
Low Frequency ◽  
Electromagnetic Testing

Dlouhodobým cílem programu řízení životnosti tlakových částí kotlů je eliminace poruchových odstávek a bezpečné provozování těchto zařízení. K detekci kritických blokací ohybů trubek odloupnutými částicemi epitaktické vrstvy byla ve spolupráci s EPRI vybrána metoda LFET (Low Frequency Electromagnetic Testing) a pro měření celkové tloušťky oxidické vrstvy metoda UT (Ultrasonic Testing), které nacházejí uplatnění zejména v USA. Ultrazvukový tloušťkoměr je použitelný pouze pro feritické materiály. Upravená metoda vířivých proudů (ET) bude sloužit ke stanovení tloušťky epitaktické vrstvy na austenitických ocelích.

scholarly journals Using Hilbert Transform in Diagnostic of Composite Materials by Impedance Method

2020 ◽  
Vol 64 (4) ◽  
pp. 334-342 ◽  
Author(s):  
Volodymyr Eremenko ◽  
Artur Zaporozhets ◽  
Vitalii Babak ◽  
Volodymyr Isaienko ◽  
Kateryna Babikova
Keyword(s):  
Composite Materials ◽  
Nondestructive Testing ◽  
Hilbert Transform ◽  
Instantaneous Frequency ◽  
Information Quality ◽  
Low Frequency ◽  
Mechanical Impedance ◽  
Phase Characteristic ◽  
Impedance Method ◽  
Materials Testing

The article is devoted to the problem of the increasing of information quality for the impedance method of nondestructive testing. The purpose of this article is to get for the pulsed impedance method of nondestructive testing the additional informative parameters. Instantaneous values of the information signal's amplitude is a sensitive parameter to the effects of interference, in particular friction, which necessitates the use of additional informative features. It was experimentally measured signals from defective and defectless areas of the test pattern. Using of the Hilbert transform gave possibility to determine phase characteristics of these signals and realize demodulation to extract a low-frequency envelope for further analysis of its shape. It was received the informative features as a result of researches. Among them are instantaneous frequency of a signal, the integral of a phase characteristic on the selected interval and the integral of a difference signal phase characteristics. In order to compare quality of the defect detection using selected parameters it was carried out evaluation of the testing result reliability for a product fragment made of a composite material. Considering the influence of the change in the mechanical impedance of the researched area on the phase-frequency characteristics of the output signal of the converter, it is proposed to use as the diagnostic signs: the instantaneous frequency and the value of the phase characteristic of the current signal for certain points in time. The proposed informative features enable to increase general reliability of composite materials testing by the pulsed impedance method.

Ultrasonic Testing in 25 Minutes

2003 ◽  
Author(s):  
William E. Blum ◽  
Thomas Gryba¨ck
Keyword(s):  
Power Generation ◽  
Quality Control ◽  
Nondestructive Testing ◽  
Ultrasonic Testing ◽  
Basic Theory ◽  
Testing Methods ◽  
Advantages And Disadvantages ◽  
Basic Understanding ◽  
Fundamental Understanding ◽  
Nondestructive Testing Methods

Nondestructive Testing (AKA NDT, NDI, NDE) is an integral part of any power generation program. Ultrasonic Testing (UT) is one NDT method used to determine the integrity of materials and components. Managers, engineers, quality control personnel and others often require a fundamental understanding of the nondestructive testing methods used in their operations. This paper introduces basic theory, advantages and disadvantages, typical equipment and applications of ultrasonic testing. It is designed to give the reader a basic understanding of ultrasonic testing.

Low‐frequency search unit for ultrasonic testing of concrete

1988 ◽  
Vol 84 (S1) ◽  
pp. S72-S72
Author(s):  
Kanji Imoto ◽  
Koji Ohta ◽  
Takeharu Watanabe
Keyword(s):  
Ultrasonic Testing ◽  
Low Frequency ◽  
Frequency Search

Buried Crack Detection in Aircraft Multi-Layer Structure Based on Pulsed Eddy Current

2013 ◽  
Vol 330 ◽  
pp. 536-541
Author(s):  
Sheng Lai ◽  
Hu Chen ◽  
Yue Wen Fu
Keyword(s):  
Crack Detection ◽  
Layer Structure ◽  
Fatigue Cracks ◽  
Low Frequency ◽  
Time Domain Analysis ◽  
Dynamic Imaging ◽  
Pulsed Eddy Current ◽  
Electromagnetic Detection ◽  
Electromagnetic Testing ◽  
Dual Polarity

The fatigue cracks of key parts, as one of the main damages of multilayer structure in aircraft, are important objects for aircraft structural health monitoring. Conventional electromagnetic testing which uses sinusoidal signal is high sensitive to surface cracks, but it is typically difficult to measure or predict embedding cracks. A novel electromagnetic detection technique is proposed in this paper, and dual polarity low-frequency pulse is used to excite the coil. A time-domain analysis method called time-slice is utilized to obtain the transient amplitude matrix from array signal. Good results have been presented by such dynamic imaging of simulating buried cracks in multi-layer riveted structure. Experimental results show that the new electromagnetic testing has the advantages of hidden defects detection and rapid detection, and it can effectively detect buried defects in multilayer structures of aircraft, and determine damage position.

Application of a HTS Coil With a Magnetic Sensor to Nondestructive Testing Using a Low-Frequency Magnetic Field

2017 ◽  
Vol 27 (4) ◽  
pp. 1-4 ◽  
Author(s):  
Yasuaki Matsunaga ◽  
Ryota Isshiki ◽  
Yuta Nakamura ◽  
Kenji Sakai ◽  
Toshihiko Kiwa ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Nondestructive Testing ◽  
Low Frequency ◽  
Magnetic Sensor ◽  
Frequency Magnetic Field

The Research of Signal Processing in Ultrasonic Nondestructive Testing and Evaluation

2013 ◽  
Vol 712-715 ◽  
pp. 2069-2075
Author(s):  
Chun An Ai ◽  
Qiao Wang ◽  
Zhi Gao Xu
Keyword(s):  
Neural Network ◽  
Support Vector Machine ◽  
Signal Processing ◽  
Nondestructive Testing ◽  
Ultrasonic Testing ◽  
Processing Technology ◽  
Support Vector ◽  
Ultrasonic Nondestructive Testing ◽  
Qualitative And Quantitative ◽  
Testing And Evaluation

The development of signal processing technology not only improves the reliability of qualitative and quantitative ultrasound detection, but also promotes the sensitivity and precision. This paper introduces the new progress of signal processing technology in application of Ultrasonic Nondestructive Testing, including the basic principle, characteristic and localization of Wavelet Transform, Adaptive Filter Technique, Artificial Neural Network and Support Vector Machine application in Ultrasonic Testing, and the trend of development in the future.

Role of interface conditions in low frequency electromagnetic testing of multilayer structures

2015 ◽  
Author(s):  
Aaron J. Cherry ◽  
Matthew R. Cherry ◽  
John C. Aldrin ◽  
Eric Lindgren ◽  
Harold A. Sabbagh ◽  
...  
Keyword(s):  
Low Frequency ◽  
Multilayer Structures ◽  
Interface Conditions ◽  
Electromagnetic Testing
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