Russian Journal of Nondestructive Testing最新文献

The possibilities of using a nondestructive acoustic method to determine the degree of hydrogenation of  VT1-0 titanium alloy are investigated. The features of using various acoustic parameters to construct computational and experimental methods for determining the porosity of titanium alloy at various stages of its hydrogenation are analyzed. The sources of errors of the proposed methods, the limits of their applicability, as well as the requirements for hardware and software for their implementation are considered. The results of acoustic measurements carried out on samples made of VT1-0 alloy are compared with the ideas about the patterns of its structural changes during hydrogenation process. The possibility is shown for creating engineering algorithms based on the obtained experimental data for assessing the state of the product material subjected to hydrogenation in order to prevent dangerous degradation of its operational properties.

This study presents a method for detecting interior hole defects using atime-flight scattered-shear wave (S-wave) methodology. Additionally, a mathematical model is proposed to quantify the detected defects accurately. The proposed method, PSO-VMD, combines variational mode decomposition with a particle swarm optimization algorithm to extract the mode conversion signal of a defect S-wave from a complex laser ultrasonic detection signal. This method effectively enhances the S-wave mode conversion signal’s signal-to-noise ratio (SNR). An experimental system using noncontact laser ultrasonic B-scanning is constructed. The system employs fixed excitation and detection methods. Experimental verification is conducted to accurately detect and identify hole flaws inside steel samples, considering variations in burial depths and diameters. The experimental results show that the proposed techniques for detection and signal processing are capable of accurately identifying and measuring hole defects. The relative positional error, which includes both transverse distance and buried depth, is below 5%, while the relative quantitative error, specifically in terms of diameter, is below 8%.

The paper presents the results of experimental and numerical investigations on water ingress trapped in aircraft honeycomb panels. The ingress of atmospheric water during aircraft service may cause minor or major damages of airplane crucial components. The percentage of water/ice filling honeycomb cells is an important factor related to possible cell damage. This study is focused on the analysis of the following inspection parameters: (1) influence of panel orientation (horizontal, vertical and Inclined at 30°, 45° and 60°) on the efficiency of water detection, (2) efficiency and optimization of a heating technique in evaluating water ingress, (3) influence of water/ice phase transformation on detectability of water ingress. The numerical analysis was conducted by using the ThermoCalc-3D software in order to evaluate the detectability of water ingress in the cases where a test panel is placed in different spatial orientations. The samples with water and ice were tested and analysed by using several data processing algorithms available in the ThermoFit software to enhance water detection performance. The signal-to-noise ratio concept was used to compare efficiency of image processing algorithms in the inspection of water ingress in honeycomb panels with varying water content, spatial orientation and water/ice phase transformation.

Formulas are given for calculating the strength of the resulting magnetic field due to magnets with a given magnetization distribution or immersed in a given field of external sources. These are the cases when the calculation using these formulas can be performed by a user who does not have much experience in the field of computational mathematics and programming. Namely, in these cases, the formulas for intensity are mostly expressed in closed form in terms of elementary functions or require the use of one of the standard routines available in the library of any programming language. Such formulas can serve as a reference material as well as for solving relevant problems with suitable real objects or for determining optimal strategies and an optimal set of input parameters when using universal software packages and estimating the error of the results obtained.

This paper designs a device that uses the difference signal of a double-layer sensor to detect steel wire rope damage, which to a certain extent suppresses the impact of the change in lifting distance on defect detection during the signal collection process. First, a simulation model was established to conduct simulation experiments, which verified the feasibility and effectiveness of the method. Secondly, a filtering algorithm using a combination of successive variational mode decomposition (SVMD) and wavelet noise reduction was proposed to analyze the collected wire rope damage signals deal with. The processed one-dimensional magnetic flux leakage signals are converted into leakage magnetic image signals, which are then used as inputs to a classification network. Finally, the improved ResNet network was used to classify and identify the damage signal. The classification accuracy of the signal collected by the single-layer sensor was 90.90%, and the classification accuracy of the signal collected by the double-layer sensor was 94.05%. The device designed in this study demonstrates a 3.15% improvement in defect classification accuracy, confirming the feasibility and superiority of using difference signals for defect detection.

Recent studies have proved the usability of the nonlinear S₀ lamb mode without satisfying the phase velocity matching criteria, and the possibility to extend its application to varying thickness plates. Based on that, this work proposes an experimental study of the inspection of macro scale localized defects with a size smaller than the used wavelength, via the second and third harmonics generation. Results were obtained on verifying their cumulative effect with varying the defect’s width and also on finding that the third harmonic is better suited for larger scale inspection using the nonlinear lamb waves, and identifying the propagating modes in the plates using the wavelet transform.

The types of defects and ways of their formation in the production of tiles from corundum ceramics are considered. The integrity of tiles containing artificial defects has been investigated by the method of active thermal nondestructive testing using optical heating. One- and two-sided thermal testing schemes as well as various methods of software processing of thermograms are applied. It has been established that the best results in detecting internal defects in ceramic tiles with a thickness of 10 mm during thermal stimulation using halogen lamps are obtained by the method of one-sided thermal testing.

This work presents an improved noncontact electromagnetic probe for near-field diagnosis and characterization, driven by a network vector analyzer (VNA) operating in the frequency range of 1 kHz to 1 GHz. Two configurations of a modified near-field microstrip probe (NFMP) are designed and studied, featuring a tip and a dipole termination. Simulations and experimental tests are conducted to assess the probe performances in detecting microcracks. Notably, the detection of cracks of 10 × 20 × 30 μm is achieved by leveraging the shift in resonance frequency. However, the impedance mismatch between the VNA and the probe presents a challenge to the system sensitivity. To address this limitation, a modification is proposed, introducing a surface-adjustable capacitance to the microstrip. This enhancement improves the probe sensitivity and enables full adjustability during measurements. An improvement of 27.13 dB in the reflection parameter is obtained. The developed probes provide nondestructive testing capabilities across a wide frequency range, from 1 kHz to 1 GHz, making them well-suited for integration with VNA systems and facilitating rapid and reliable external measurements.

A procedure for determining lithium concentration in formation waters by NMR relaxometry is proposed. The method makes it possible to quickly determine the lithium content for concentrations of industrial interest. The experiments have shown good agreement between the data obtained by the proposed method and the data obtained by the induction coupled plasma (ICP) method.