Ultrasonic Measurement of the Crack Depth and the Crack Opening Stress Intensity Factor Under a No Load ConditionJournal of Nondestructive Evaluation - Tập 23 - Trang 49-63 - 2004
M. Saka, M. A. Salam Akanda
This paper describes a new methodology for evaluating the crack depth and the crack opening stress intensity factor of small closed cracks using an ultrasonic technique. Surface connected back-wall cracks of depth ranging from 0.4 to 4.0 mm in steel specimens are considered. The crack corner echo amplitude of an ultrasonic shear wave, SW, beam of 50° incidence in material is used. First, the ultra...... hiện toàn bộ
Ultrasonic Testing of Corrosion in Aircraft Rivet Using Spiking Neural NetworkJournal of Nondestructive Evaluation - Tập 42 - Trang 1-11 - 2023
Minhhuy Le, Jinyi Lee
This paper proposes a nondestructive testing (NDT) method for the inspection of corrosion in rivets used in an aircraft. The NDT system uses an ultrasonic sensor coupling with a membrane that allows the ultrasonic wave propagates through to the inspecting rivet. The measured signal is then analyzed by a spiking neural network (SNN), a neural network that mimics the biological neurons for efficient...... hiện toàn bộ
Surface electromagnetic fields around surface flaws in metalsJournal of Nondestructive Evaluation - Tập 5 - Trang 81-93 - 1985
R. Collins, D. H. Michael, D. Mirshekar-Syahkal, H. G. Pinsent
In an earlier paper(3) it was shown mathematically and confirmed by experiment that when a uniform surface alternating conduction current is incident on a spherical cap indentation at the surface of a metal there is no perturbation to the current flow on the plane surface outside the cap. It is shown here that this result is true of all axisymmetric surface cavities which are interrogated by any f...... hiện toàn bộ
Ultrasonic wave propagation in temperature gradientsJournal of Nondestructive Evaluation - Tập 6 - Trang 147-157 - 1987
John A. Johnson, Nancy M. Carlson, Layman A. Lott
Ultrasonic methods are being developed for sensing and control of high temperature material processes such as welding and solidification. One of the problems in these methods is the distortion of the sound field caused by the change in material properties due to temperature gradients. This paper describes a ray-tracing method for calculating the effects of temperature on ultrasonic propagation in ...... hiện toàn bộ
A comparison of Q-switched and intensity modulated laser pulses for ultrasonic NDTJournal of Nondestructive Evaluation - Tập 17 - Trang 199-208 - 1998
Terry Sanderson, Charles Ume, Jacek Jarzynski
The purpose of this work was to investigate the potential of intensity modulated laser pulses for ultrasonic signal enhancement in NDT using a numerical model. Q-switched lasers produce broadband ultrasound which is susceptible to measurement noise. Intensity modulation can alleviate this problem by focussing the ultrasonic energy into a band centered around the modulation frequency. Ultrasonic wa...... hiện toàn bộ
A Comparison of Machine Learning Methods for the Diagnosis of Motor Faults Using Automated Spectral Feature Extraction TechniqueJournal of Nondestructive Evaluation - Tập 41 - Trang 1-19 - 2022
Muhammad Irfan, Abdullah Saeed Alwadie, Faisal AlThobiani, Khurram Shehzad Quraishi, Mohammed Jalalah, Ali Abbass, Saifur Rahman, Mohammad Kamal Asif Khan, Samar Alqhtani
Centrifugal pumps (CPs) are mainly composed of impeller and bearings. The operation of the CPs is disturbed if any of its components is faulty. Bearings faults are reported to be the major reason for pump failures. Condition monitoring of the CPs helps in early diagnosis and assists to keep machines in working condition with minimum maintenance costs. Famous non-intrusive techniques known as motor...... hiện toàn bộ
Boundary integral equation methods for two-dimensional models of crack-field interactionsJournal of Nondestructive Evaluation - Tập 7 - Trang 3-14 - 1988
Arnold H. Kahn
An introduction to the application of surface integral equation methods to the calculation of eddy current-flaw interactions is presented. Two two-dimensional problems are presented which are solved by the boundary integral equation method. Application of collocation methods reduces the problems to systems of linear algebraic equations. The first problem is that of a closed surface crack in a flat...... hiện toàn bộ
Analysing the Probability of Detection of Shallow Spherical Defects by Means of Pulsed ThermographyJournal of Nondestructive Evaluation - Tập 42 - Trang 1-16 - 2023
E D.’Accardi, D Palumbo, V Errico, A Fusco, A Angelastro, U Galietti
The capability of Active Thermography (AT) techniques in detecting shallow defects has been proved by many works in the last years, both on metals and composites. However, there are few works in which these techniques have been used adopting simulated defects more representative of the real ones. The aim of this work is to investigate the capability of Pulsed Thermography of detecting shallow sphe...... hiện toàn bộ