scholarly journals Increase of the Informative Value of Magnetic Nondestructive Testing Using Vibration Induction Transducer on the Basis of Spectral Analysis

2021 ◽  
Vol 2091 (1) ◽  
pp. 012048
Author(s):  
Yu L Nikolaev ◽  
P N Shkatov ◽  
A V Chernova ◽  
E F Akhmetshina ◽  
A A Samorukov
Keyword(s):  
Spectral Analysis ◽  
Nondestructive Testing ◽  
Flaw Detection ◽  
Magnetic Scattering ◽  
Noise Component ◽  
Linearly Independent ◽  
Induction Transducer ◽  
Harmonic Components ◽  
Magnetic Flaw Detection ◽  
Weakly Dependent

Abstract The ways of increasing the information content of magnetic flaw detection based on spectral analysis when registering magnetic fluxes of leakage from defects by a vibration induction probe (VIP) are considered. It is shown that the VIP signals, caused by the normal and tangential components of the strength of the magnetic scattering fluxes, are linearly independent, and the corresponding harmonic components of the spectra of these signals are weakly dependent on the noise component and carry information about the coordinates and parameters of the defect.

scholarly journals Difficulties with phase spectrum unwrapping in spectral analysis of surface waves nondestructive testing of pavements

1992 ◽  
Vol 29 (3) ◽  
pp. 506-511 ◽  
Author(s):  
M. O. Al-Hunaidi
Keyword(s):  
Spectral Analysis ◽  
Nondestructive Testing ◽  
Surface Waves ◽  
Phase Spectrum ◽  
Correction Procedure ◽  
Near Surface ◽  
Surface Profiling ◽  
Usual Procedure

Spectral analysis of surface waves (SASW) is a nondestructive and in situ method for determining the stiffness profiles of soil and pavement sites. This method involves the generation and measurement of surface Rayleigh waves. By exploiting the dispersive characteristic of these waves in layered systems, the SASW method provides information on the variation of stiffness with depth. This paper presents the results of a case study for near-surface profiling of a pavement site using the SASW method. In this study, inconsistencies were observed in the dispersion curve of the site when the usual procedure of unfolding the relative phase spectrum was followed. A correction procedure to eliminate these inconsistencies is suggested and discussed. The thickness and wave velocities of the various layers obtained with the SASW method, after applying the correction procedure, matched closely those determined from cored samples and cross-hole tests. Key words : nondestructive testing, pavement, layered media, Rayleigh wave, spectral analysis, shear wave velocity, wave propagation.

The Calculation and Analysis of the Infrared Thermal Wave Nondestructive Testing for the Defects of the Parts in the Turnout Point Switch

2013 ◽  
Vol 328 ◽  
pp. 393-399 ◽  
Author(s):  
Ping Yang ◽  
Ge Jing ◽  
Cui Ming Li
Keyword(s):  
Nondestructive Testing ◽  
Thermal Wave ◽  
Flaw Detection ◽  
Simulation Test ◽  
Numeric Simulation

This paper did quantitive flaw detection research to the defective parts of turnout point switch by using infrared thermal wave nondestructive testing based of the theory of infrared nondestructive testing. By using ANSYS, I made the numeric simulation test to parts of the inside known defection point switch, and made calculation and analysis for the result of this numeric simulation test. The result demonstrated that this method can achieve the quantitive infrared thermal wave nondestructive testing to defective parts of point switch.

Metrological Assurance of Magnetic Flaw Detection of Steel Ropes

2017 ◽  
Vol 59 (11) ◽  
pp. 1197-1201 ◽  
Author(s):  
M. V. Nemtsov ◽  
G. D. Trifanov
Keyword(s):  
Flaw Detection ◽  
Metrological Assurance ◽  
Magnetic Flaw Detection

ON POWER ESTIMATION IN MAXIMUM ENTROPY SPECTRAL ANALYSIS

Geophysics ◽  
1978 ◽  
Vol 43 (4) ◽  
pp. 681-690 ◽  
Author(s):  
S. J. Johnsen ◽  
N. Andersen
Keyword(s):  
Spectral Analysis ◽  
Spectral Density ◽  
Maximum Entropy ◽  
Power Estimation ◽  
Low Noise ◽  
Density Estimator ◽  
Simple Method ◽  
Power Estimate ◽  
Maximum Entropy Spectral Analysis ◽  
Harmonic Components

A conceptually simple method for power estimation in maximum entropy spectral analysis, based on evaluation of complex residues of the spectral density estimator, is suggested. Numerical integration of the peaks of the power density function is thus avoided. The agreement in simple cases with conventional estimates is demonstrated, and the explicit performance is analyzed in detail in a series of examples. The close connection between the residue power estimate and the estimate proposed recently by Pisarenko is pointed out. The method is particularly suitable for spectral decomposition of low noise time series with several harmonic components, because it allows a direct listing of frequency and power estimates, provides an indication of the purity of the obtained harmonic components and enhances the resolution of the maximum entropy spectral density estimator. Computing facilities with modern program libraries are required for efficient use of the method.

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