Non-destructive Diagnostics Research Articles

Quanitification of Netting Patterns Occurring in Muskmelons and Prospects for Non-Destructive Diagnostics

Quanitification of Netting Patterns Occurring in Muskmelons and Prospects for Non-Destructive Diagnostics

Cross-Scale Decoupling Kinetic Processes in Lithium-Ion Batteries Using the Multi-Dimensional Distribution of Relaxation Time.

To non-destructively resolve and diagnose the degradation mechanisms of lithium-ion batteries (LIBs), it is necessary to cross-scale decouple complex kinetic processes through the distribution of relaxation times (DRT). However, LIBs with low interfacial impedance render DRT unreliable without data processing and closed-loop validation. This study proposes a hierarchical analytical framework to enhance timescale resolution and reduce uncertainty, including interfacial impedance reconstruction and multi-dimensional DRT analysis. Interfacial impedance is reconstructed by eliminating simulated inductive and diffusive impedance based on a high-fidelity frequency-domain model. Multi-dimensional DRT decouples solid electrolyte interphase (SEI) and charge transfer (CT) processes by the reversibility of electrochemical reactions with state of charge (SOC) to characterize electrode kinetic evolution driven by SOC and temperature through timescales and peak area. The findings reveal that reconstructed impedance improves the accuracy of identified time constants by ≈20%. Cross-scale DRT results reveal that SOCs below 10% at 25 °C effectively distinguish electrode kinetics due to the high correlation between cathodic CT and SOC. Kinetic metrics characterize that anodic SEI or CT are different control steps limiting the low-temperature performance of different cells. This work underscores the potential of the proposed framework for non-destructive diagnostics of kinetic evolution.

Improving sensitivity of XANES structural fit to the bridged metal-metal coordination.

Hard X-ray absorption spectroscopy is a valuable in situ probe for non-destructive diagnostics of metal sites. The low-energy interval of a spectrum (XANES) contains information about the metal oxidation state, ligand type, symmetry and distances in the first coordination shell but shows almost no dependency on the bridged metal-metal bond length. The higher-energy interval (EXAFS), on the contrary, is more sensitive to the coordination numbers and can decouple the contribution from distances in different coordination shells. Supervised machine-learning methods can combine information from different intervals of a spectrum; however, computational approaches for the near-edge region of the spectrum and higher energies are different. This work aims to keep all benefits of XANES and extend its sensitivity towards the interatomic distances in the first and second coordination shells. Using a binuclear bridged copper complex as a case study and cross-validation analysis as a quantitative tool it is shown that the first 170 eV above the edge are already sufficient to balance the contributions of Cu-O/N scattering and Cu-Cu scattering. As a more general outcome this work highlights the trivial but often overlooked importance of using `longer' energy intervals of XANES for structural refinement and machine-learning predictions. The first 200 eV above the absorption edge still do not require parametrization of Debye-Waller damping and can be calculated within full multiple scattering or finite difference approximations with only moderately increased computational costs.

The systematic structural studies of some Byzantine ceramic fragments from Dobrudja region of Romania: Raman spectroscopy, neutron diffraction, and imaging data

AbstractThe systematic studies of composition and spatial distribution of main phases inside volume of 25 fragments of Byzantine ceramic obtained in archeological works in the Dobrudja region, Romania, have been performed using neutron diffraction and tomography, and Raman spectroscopy. The obtained structural data on the content of phases, the presence of calcite grains and pores, and the uniformity of phase spatial distribution made it possible to systematize the studied fragments and correlate them with clay sources or pottery workshop. The experimental possibilities of neutron methods of nondestructive structural diagnostics as well as the structural markers provided by them in the studies of ceramic samples are discussed.

Risk-based approach to choosing the production asset management strategy for energy company

RELEVANCE: The possibility of a reasonable choice of an alternative strategy for the organization of maintenance and repair (M&R) of the power company's equipment is a guarantee of the successful implementation of its strategic priorities. The tasks in this direction are quite relevant.PURPOSE: To develop a unified methodology that, from the general standpoint of a risk-based approach, would allow comparing two alternative strategies for managing the assets of an energy company "by periodicity, operating time" and "by technical condition", according to a set of key criteria for the effectiveness of M&R.METHODS: When solving problems, methods of forming and adjusting schedules for repairs of electrical equipment, calculating reliability and probabilities of failure in the power supply system of consumers, taking into account its circuit features, assessing the technical condition of equipment according to non-destructive testing and diagnostics, comparing the costs of maintaining and restoring reliability and damages from its violations were used.RESULTS: A risk-oriented methodology has been developed and verified, which makes it possible to evaluate and select the optimal equipment maintenance strategy for the energy company according to uniform efficiency criteria. An algorithmic implementation of the developed methodology is obtained, which is the basis of a computing complex for choosing and making decisions. The verification of the methodology and algorithm is carried out on the example of a real object – a power supply system for oil production consumers using reliable operational and diagnostic information.CONCLUSION: The results obtained fully compensate for the lack of methodological possibilities in comparing two basic alternative strategies for electrical equipment maintenance based on a single risk-based approach. The developed methodology is a unified decision-making tool at the stage of alternative analysis. The illustration of the methodology by a real numerical example demonstrates the consistency of the solutions obtained with the results of expert assessments and operational experience.

Методология диагностических испытаний центрифугированных железобетонных опор контактной сети

The article discusses various methods of non-destructive diagnostics of defects in contact network supports, examines the principles of operation of existing diagnostic methods, gives the reasons for the appearance of defects in reinforced concrete pillars, and proposes a conceptual idea for a diagnostic test journal based on a local QR code.

Automated detection and segmentation of internal defects in reinforced concrete using deep learning on ultrasonic images

Periodic inspection of concrete structures for detecting internal defects through nondestructive imaging is recommended for ensuring structural safety and integrity. Ultrasonic imaging is one of the emerging and widely accepted techniques in nondestructive diagnostics of concrete structures. However, manually screening the ultrasonic images to detect and localize anomalies over large areas especially those from public infrastructure is tedious and prone to misjudgments. This work proposes a Region-based CNN to automatically detect, localize, and segment those signatures corresponding to defects from the noisy ultrasonic images with multiple features. This network replaces the conventional RoI pooling adopted in RCNNs with RoIAlign. To optimize the model for real-life complexity and noise levels, the network is trained on real experimental data. The ultrasonic image dataset has been generated by applying the imaging technique based on the Synthetic Aperture Focusing Technique on reflected waveform data obtained on various specimens with installed defects. The proposed network has been trained on the labelled image dataset containing signatures corresponding to multiple flaws like debonded rebars, delaminations, and planar crack-like defects in concrete members. The predictions of the trained model over the test datasets detect and masks the pixels corresponding to defects in ultrasonic images with a best mAP of 0.98. Segmentation results of the developed model upon testing are found superior to other state-of-the-art defect detection networks.

A study on microcrack monitoring in concrete: discrete element method simulations of acoustic emission for non-destructive diagnostics

The research is focused on the monitoring of fracture evolution in concrete beams under three-point bending using the acoustic emission technique and the discrete element method. The main objective of the study was to numerically and experimentally investigate the mechanism behind the generation of elastic waves during acoustic emission events and their interaction with micro- and macro-cracking in concrete beams under monotonic quasi-static loading. This was achieved through the development of a DEM model and numerical modelling of AE effects. An improved 4-phase DEM model of concrete including real mesostructured specimens and the ability to simulate aggregate breakage was introduced. The propagation of elastic waves, recorded in both laboratory experiments and numerical calculations, was given particular attention. The results showed the high suitability of the developed DEM model for monitoring crack initiation, development and propagation, as well as for supporting the interpretation of diagnostic results obtained by acoustic emission techniques.

A voltage reconstruction model for lithium-ion batteries considering the polarization process

Health assessment is one of the most crucial components in lithium-ion battery (LIB) management. However, traditional methods often require disassembling LIBs, which are inconvenient for implementation. On the contrary, non-destructive diagnostics can obtain the aging information of LIBs without causing damage to batteries, which is beneficial for the periodic inspection and secondary use of LIBs in other fields. Therefore, accurate non-destructive diagnostics is necessary in practical applications. This paper proposes a new voltage reconstruction model considering the polarization process to get the battery internal information. Through matching the equilibrium potentials of the positive and negative electrodes, combined with an equivalent circuit model, this voltage reconstruction model can accurately simulate the whole charging and discharging processes of LIBs. The parameters with clear physical interpretation in the model can be quickly and accurately identified within the MATLAB software, and these parameters can be used to quantitatively identify the degradation modes of LIBs. Finally, the post-mortem analysis of the aged LIB is used for verification. The results show that the proposed model could precisely reflect the battery internal ageing information and could be used for online diagnostics in real electric vehicles.

Estimating complex dielectric permittivity of materials by the frequency dependences of reflection and transmission coefficient magnitudes in the microwave range

Electromagnetic waves of the microwave range are an effective tool for solving problems of non-destructive testing and diagnostics as applied to dielectric, semiconductor, and composite materials, ferrite products. An algorithm is suggested for estimating the complex permittivity of non-magnetic materials by the frequency dependences of reflection and transmission coefficient magnitudes during the interaction of electromagnetic waves in the microwave range with a sample in the form of a plate located in the cross section of a closed rectangular waveguide. Statistical analysis methods are applied to evaluating the errors arising during the application of this algorithm due to imperfect matching of the waveguide measurement path with the receivers and generator of the scalar circuit analyzer. It is shown that the proposed algorithm using the results of measuring reflection and transmission coefficients in a wide frequency range can significantly reduce the influence of frequency-dependent measurement errors on the accuracy of complex permittivity estimation. An additional advantage of the algorithm is that its implementation does not require vector network analyzers, which are very expensive.

Reduced-Order Models Correlating Ti Beta 21S Microstructures and Vickers Hardness Measurements

Ti Beta 21S alloy is a metastable Ti Beta alloy commonly used in the aerospace industry, especially in jet engines. Components made from this alloy are usually subjected to various thermal histories during service, which leads to significant changes in their microstructures and associated mechanical properties. The central goal of this study is to demonstrate the feasibility of correlating the optical images of the microstructure obtained from heat-treated samples of Ti Beta 21S to their respective Vickers hardness measurements using recently established analyses and statistical quantification approaches based on the principal components of the rotationally invariant 2-point spatial correlations. The correlations extracted in this work can be used for non-destructive diagnostics of in-service components.

LASER-ULTRASOUND DIAGNOSTICS OF PLASTIC PRODUCTS MANUFACTURED BY LASER STEREOLITHOGRAPHY

Abstract. This paper discusses the application of methods of non-destructive testing and flaw detection of plastic products manufactured by additive technologies. The modern development of additive technologies associated with the active transition from the manufacture of prototypes and test samples to the manufacture of functional products increases the requirements for improving the quality of manufacturing and conducting non-destructive diagnostics of finished products, including plastic materials. The overall productivity of the production process can be increased by increasing the yield due to a decrease in the number of defects, which is ensured by process control and the quality of finished products. The method of laser-ultrasound diagnostics allows monitoring and flaw detection of products made of different materials with good spatial resolution, which is not always possible, for example, by tomographic scanning. Thus, the main purpose of this work is to evaluate the possibility of using laser-ultrasonic methods to detect potential defects and to track the impact of the additive manufacturing process on the quality of plastic products.

Non-invasive identification of combined salinity stress and stalk rot disease caused by Colletotrichum graminicola in maize using Raman spectroscopy

Food security is an emerging problem that is faced by our civilization. There are millions of people around the world suffering from various kinds of malnutrition. The number of people that starve will only increase considering the continuous growth of the world’s population. The problem of food security can be addressed by timely detection and identification biotic and abiotic stresses in plants that drastically reduce the crop yield. A growing body of evidence suggests that Raman spectroscopy (RS), an emerging analytical technique, can be used for the confirmatory and non-invasive diagnostics of plant stresses. However, it remains unclear whether RS can efficiently disentangle biotic and abiotic stresses, as well as detect both of them simultaneously in plants. In this work, we modeled a stalk rot disease in corn by inoculating the plant stalks with Colletotrichum graminicola. In parallel, we subjected plants to salt stress, as well as challenging plants with both stalk rot disease and salinity stress simultaneously. After the stresses were introduced, Raman spectra were collected from the stalks to reveal stress-specific changes in the plant biochemistry. We found that RS was able to differentiate between stalk rot disease and salinity stresses with 100% accuracy, as well as predict presence of both of those stresses in plants on early and late stages. These results demonstrate that RS is a robust and reliable approach that can be used for confirmatory, non-destructive and label-free diagnostics of biotic and abiotic stresses in plants.

Virtual-diagnostic-based time stamping for ultrafast electron diffraction

In this work, non-destructive virtual diagnostics are applied to retrieve the electron beam time of arrival and energy in a relativistic ultrafast electron diffraction (UED) beamline using independently-measured machine parameters. This technique has the potential to improve temporal resolution of pump and probe UED scans. Fluctuations in time of arrival have multiple components, including a shot-to-shot jitter and a long-term drift which can be separately addressed by closed loop feedback systems. A linear-regression-based model is used to fit the beam energy and time of arrival and is shown to be able to predict accurately behavior for both on long and short time scales. More advanced time-series analysis based on machine learning techniques can be applied to improve this prediction further.

Dopant profiling of ion-implanted GaAs by terahertz time-domain spectroscopy

We investigate terahertz time-domain spectroscopy (THz-TDS) as a non-destructive and non-contact technique for depth profiling of dopants in semiconductors. THz temporal waveforms transmitted through silicon-ion-implanted semi-insulating gallium arsenide substrates, as-implanted or post-annealed by rapid thermal annealing, were analyzed by assuming a multi-layered Gaussian refractive index profile in the ∼sub-micrometer-thick implantation region. The implantation energy and dosages in this work were 200 KeV, 1014, 5 × 1014, and 1015 ions/cm2, respectively. The average values of real (n) and imaginary (κ) parts of refractive indices of an as-implanted sample in the depth range of 0–800 nm are 5.8 and 0.7, respectively, at 0.5 THz and are 6.2 and 0.2, respectively, at 1 THz. On the other hand, the refractive index profile of the post-annealed samples displays a prominent Gaussian-like form, and peak refractive indices (n ∼ 25 and κ ∼ 32.7 at 0.5 THz and n, κ ∼17 at 1 THz) were found to be at the depth of 210 nm. Reconstructed dopant profiles in as-implanted, implanted, and post-annealed substrates were found to be in good agreement with measurements by secondary ion mass spectroscopy as well as simulation by the Monte Carlo method. We were also able to determine accurately the projected range (Rp), straggle (Rs), and concentration of dopants by the analysis of THz-TDS data. The spatial resolution, along the depth direction, of the THz-TDS technique for depth profiling of dopants was estimated to be as small as 8-nm. This work suggests the feasibility of using THz-TDS for nondestructive and non-contact diagnostics for profiling dopants in semiconductors.

Integrated dynamical phase-variation diffracto-metry of single crystals with defects of three and more types

Generalization of the methods for the purposeful influence of the interrelated variations inherent to different experimental conditions on changes in the selectivity of the sensitivity of the azimuthal dependence of the total integrated intensity of dynamical diffraction to various types of defects in single crystals has been carried out. As a result, the improved phase-variation methods with additionally increased sensitivity and informativity of non-destructive structural diagnostics aimed at multi-parametrical single crystal systems have been developed.

A Multi-Parametric Investigation on Waterlogged Wood Using a Magnetic Resonance Imaging Clinical Scanner

In cultural heritage conservation science, moisture content (MC) is an essential factor to determine. At the same time, it is essential to choose non-destructive and non-invasive approaches for more sustainable investigations and make them safe for the environment and the sample. The question addressed in this work concerns the possibility and the opportunity to investigate waterlogged wood by using nuclear magnetic resonance imaging (MRI) clinical scanners to carry out non-destructive volumetric diagnostics. In this study, MRI, the most important non-invasive medical imaging technique for human tissue analysis, was applied to study archaeological waterlogged wood samples. This type of archaeological material has a very high moisture content (400%–800%), thus, it is an ideal investigative subject for MRI which detects water molecules inside matter. By following this methodology, it was possible to obtain information about water content and conservation status through a T1, T2, and T2* weighted image analysis, without any sampling or handling, and the samples were directly scanned in the water where they were stored. Furthermore, it permited processing 3D reconstruction, which could be an innovative tool for the digitalization of marine archaeological collections. In this work, 16 modern species of wood and a waterlogged archaeological wood sample were studied and investigated using a clinical NMR scanner operating at 3T. The results were compared with X-ray computed tomography (CT) images, as they had already been used for dendrochronology. The comparison highlights the similar, different, and complementary information about moisture content and conservation status in an all-in-one methodology obtainable from both MRI and CT techniques.

Ultrasonic diagnostics in the study of coatings applied by gas-flame spraying

The quality control of coatings when selecting a powder material for the restoration of worn surfaces by gas-flame spraying is hampered by the lack of an operational method of non-destructive diagnostics. We present the results of studying coatings applied by gas-flame spraying using ultrasonic diagnostics. The powder coatings obtained using different technologies of gas-flame spraying were studied. Features of the structural state of coatings were evaluated using a model based on the effect of the structural inhomogeneities of the coating on the velocity and attenuation of ultrasonic waves. It is shown that the amplitude-time characteristics of the pulse of surface elastic waves when they pass along the coating are consistent with the data obtained from friction and hardness tests, the characteristics of the pulse being dependent on the quality of the coating material. The obtained results can be used to improve the quality control of coatings formed by gas-flame spraying.

Nondestructive diagnostics and quantification of battery aging under different degradation paths

Identification and quantification of degradation mechanisms of lithium ion batteries are crucial but highly challenging due to their complex coupling effects and varying operating conditions. In this paper, we propose a nondestructive aging diagnostics methodology by identifying aging-related parameters of a physics-based battery model from the beginning-of-life (BOL) to end-of-life (EOL). The proposed method is applied and validated on 7 cells at 4 test conditions, considering different cycling conditions, cell-to-cell variations and calendar aging. Nearly 200 identifications of 12 aging-related parameters are performed at different degradation stages across the lifetimes of those cells. By observing the evolution trajectories of those parameters at different cycle and calendar aging scenarios, we show quantitatively that the degradation rates of the cells are impacted by different patterns in the changes of aging parameters. The method could also capture subtle cell-to-cell variations in battery degradation by quantifying the discrepancies of the aging parameters over time. This work demonstrates the promise of applying physics-based models for nondestructive degradation diagnostics and provides a quantitative perspective for degradation modes analysis.

Reference installation for measuring acoustic parameters of solids

The issues of providing working standards of the 1st category of metrological organizations of the country with regard to modern needs in the field of ultrasonic measurements in solids are considered. There is presented a modernized reference installation designed for precision measurements of propagation velocities of longitudinal and shear ultrasonic waves and damping coefficient of longitudinal ultrasonic waves in solids. Measurements of acoustic parameters of solid media are made by pulse-echo and resonance methods using contactless broadband capacitive methods of excitation and registration of ultrasonic waves. This installation is used as working standard of the 1st category in accordance with the state verification schedule for measuring instruments of the propagation velocities and damping coefficient of ultrasonic waves in solids. The technical means included in the installation (mechanical and electronic parts) have been improved, analog measuring means have been replaced with digital ones, methods for measuring acoustic parameters of solids based on the use of digital measuring means have been developed and the thickness range of installed ultrasonic measures has been expanded. The composition and main components of the reference installation, the used measurement methods and the principles of operation of the installation in various operating modes are described. The technical and metrological characteristics of the installation are given. Sources of measurement error (uncertainty) were analyzed. The field of application of the results is high-precision measurements of the acoustic characteristics of solid media, metrological ensuring of ultrasonic non-destructive testing and diagnostics.