bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-sensing metallic material based on piezoelectric particles
Authors:   NOVA University of Lisbon, Ferreira Pedro M. ,   NOVA University of Lisbon, Machado Miguel A. ,   NOVA University of Lisbon, Carvalho Marta S. ,   NOVA University of Lisbon, Vidal Catarina
Published: July 2023

Structural parts’ integrity should remain as specified and designed, although it can change due to ageing and use by environmental action and accidental events. Structural parts design is carried out considering certain service conditions that can be different from operating conditions. These parts often experience dynamic solicitations that change in amplitude and frequency over time, which may cause the part’s failure. The part’s real condition can be assessed by Structural Health Monitoring systems, which grant significant social, economic, and environmental impact, as they can reduce maintenance costs and ensure the integrity of the part and its surroundings. This can be performed with an integrated monitoring system comprising sensors, on the surface or embedded, into the components. However, surface sensors are subject to damage, from collisions and/or environmental action, and embedding sensors can be very challenging and may result in a weakened part. A Self-Sensing Material (SSM) was developed based on piezoelectric particles embedded in metal parts by a solid-state processing technology. The material can act as a sensor and continuously monitor its condition. The SSM's generates an electrical voltage signal when subject to strain stimulus. Moreover, the solid-state processing technology employed promotes mechanical properties enhancement in the processed zone, not only by the grain size reduction but also due to the incorporation of the piezoelectric particles. The response to a set of dynamic loads was assessed and was found to be coherent with the solicitations applied.
Ad-hoc solutions for ultrasonic inspection of highly complex aircraft composite structures
Authors:   Center for Advanced Aerospace Technologies (FADA-CATEC), Herrera Marta ,   Center for Advanced Aerospace Technologies (FADA-CATEC), Vilches Celia ,   Center for Advanced Aerospace Technologies (FADA-CATEC), González Sergio ,   Center for Advanced Aerospace Technologies (FADA-CATEC), Lasagni Fernando
Published: July 2023

Nowadays, the ultrasonic inspection (UT) is the most common non destructive technique (NDT) for composite components in the aerospace industry, due to its high accuracy, reliability and the degree of industrialization. Although UT is widely developed, new manufacturing processes and part concepts are continuously pushing the technology for new improvements and applications. This is the case of the geometries resulting from novel out of autoclave composites manufacturing technologies, Liquid Resin Infusion (LRI) or Resin Transfer Moulding (RTM), allow the fabrication of parts in one shoot, with focus in bringing answers to the challenge of manufacturing fully assembled parts and avoiding secondary assembly phases but also limiting the accessibility for NDT inspections. In this sense, one of the critical issues in the aeronautic sector is the improvement of the inspection of geometries with difficult access and small dimensions. The requirement of the aeronautic industry of guaranteeing the quality of the primary composite structures implies the inspection of the whole component through certified technologies. This constraint, together with the lack of technological solutions for the inspection of regions with limited accessibility is blocking the industrial implementation of optimized manufacturing processes. The present work describes the design and development of adaptive hardware solutions for the single and phased array UT inspection of internal structures on a highly integrated composite aeronautic component. The final solution has been obtained as result of an iterative design process and manufactured through additive manufacturing technology (Powder Bed Laser Fusion, formerly Selective Laser Sintering) using polyamide. This device was validated in a for inspection of flat surfaces of stiffener internal structure, belonging to the composite flap demonstrators of lengths: 3 meters in a first approach, and 8 m for final validation. This novel inspection solution has been performed in the framework of the FLAP project to develop and innovate the manufacturing process for complex mobile surfaces in a collaboration between Aernnova, through its Composites Division, and CATEC teams.
Virtual encoder: a two-dimension visual odometer for NDT
Authors:   Federal University of Technology (UTFPR), Kalid Thiago E. ,   Federal University of Technology (UTFPR), Trento Jr. Everton ,   Federal University of Technology (UTFPR), Prado Tatiana de Almeida ,   Petrobras Research Center, Pires Gustavo P. ,   Federal University of Technology (UTFPR), Guarneri Giovanni A. ,   Federal University of Technology (UTFPR), Passarin Thiago Alberto Rigo ,   Federal University of Technology (UTFPR), Pipa Daniel Rodrigues
Published: July 2023

Odometer information is an important feature of NDT systems for inspection procedures that involve mechanical scanning. Knowledge of transducer position during the inspection allows for the localization of flaws and the fusion (stitching) of several images into more sophisticated representations of the inspected object. Commercial encoders provide NDT systems with accurate realtime displacement information that can be integrated to obtain odometry. However, this information is typically limited to a single axis. Although composite schemes with more than one encoder can be built to provide 2-D or 3-D spatial information, they are mechanically intricate and lack flexibility and ease of use. We propose a 2-D position-tracking solution that is based on image processing. A miniature camera continuously captures images of the external surface of the inspected object, which are fed to an algorithm that detects and stores 2-D displacement between each pair of consecutive images. Additionally, the orientation quaternions provided by an Inertial Measurement Unit are stored, allowing for posterior 3-D path reconstruction over objects of known geometries, such as oil pipes. Besides logging position and orientation histories, the device also provides real-time displacement information to the NDT system, where it is perceived as a set of single-axis encoders, thus termed “the virtual encoder”. We demonstrate the applicability of the device to both contact and immersion ultrasonic inspections. The results show that the concept is promising, despite being based on simple principles and relatively easy to implement. The source code is provided as additional material in https://github.com/thiagokalid/VirtualEncoder-ECNDT-2023.
Ultrasonic sectorial inspection in the presence of temperature gradients
Authors:   Federal University of Technology (UTFPR), Müller Mateus Yamada ,   Federal University of Technology (UTFPR), Prado Tatiana de Almeida ,   Federal University of Technology (UTFPR), Kalid Thiago Estrela ,   Federal University of Technology (UTFPR), Passarin Thiago Alberto Rigo ,   Federal University of Technology (UTFPR), Pipa Daniel Rodrigues
Published: July 2023

Ultrasonic nondestructive testing is a precise tool for equipment inspections. Among

the usual methods, sectorial scanning stands out within contact-based techniques, as it

provides broad angular sweeps without the need to physically steer the transducer, and

the configuration of the beams hinges on the geometry of the tested objects. However,

in high-temperature scenarios (e.g., oil treatment vessels), thermal gradients along the

propagation path result in inaccurate sizing of discontinuities, given that the presence of

such gradients is responsible for variations in the velocities and distortions of the ultrasonic beams. This paper proposes a method to compensate for these distortions during

the sectorial inspection. Optimal linear approximation parameters are determined offline from a controlled Full Matrix Capture (FMC) test, in which the setup consists of

a phased array transducer, a high-temperature resistant wedge and an aluminium test

block with flaws at known positions. The positions of the flaws are measured on the

Total Focusing Method (TFM) reconstructions, and the parametric velocity models for

specific instants of heating time are estimated through the minimization of a cost function. Then, focal laws are calculated from the parameters using the ray tracing technique

and stored in a text file to be interpreted by the instruments as a native focal law. An

online test is proposed for validating the method at the controlled temperature of 70oC.

The results show that the positions of the flaws, and the distance between them in the

S-scan image, present improved accuracy (with errors reduced by approximately 64%)

when the proposed correction is applied.
Application of Non-destructive Testing in Quality Control of Manufactured Aluminium Metal Matrix Composite Components for the Automotive Industry
Authors:   ISQ, Proença C. Sofia ,   ISQ, Morais Paulo ,   ISQ, Salgueiro F. ,   EWF, Correia Beatriz ,   EWF, Lopez Ana Beatriz ,   OGI, Kneissl C. ,   OGI, Petkov T.
Published: July 2023

The manufacturing of automotive components using aluminium metal matrix composites (Al-MMCs) is progressively gaining a relevant place in the automotive industry. Due to the increasing competition in the automobile sector, there is a great need to supply efficient, stable, and high-quality products. Generally, following automotive standards is voluntary, which means that businesses and other organizations are not legally obliged to apply them. Nevertheless, in certain cases standards may facilitate compliance with legal requirements, such as those contained in European directives and regulations. IATF 16949:2016 is the current version of the IATF 16949 Standard and outlines the requirements an organization must maintain in their quality system for IATF 16949 certification. This new application of manufacturing Al-MMCs requires additional procedures to guarantee the quality of the components manufactured. Because the manufacturing process may generate various defects, such as cracks, voids, lack of fusion, inclusions, porosities, and other metallurgical aspects, non-destructive testing (NDT) techniques should be used for guaranteeing the quality of the components manufactured. The development of reliable NDT methods for aluminium metal matrix composite parts is thus a major challenge. This aspect is related to how NDT procedures need to be optimised or developed to address the singular structures of the processes, such as complex geometry, anisotropic material properties, special internal structures, and the presence of nanoparticles. The main objective of this work is to summarize and present the relevant potential of different NDT techniques used in quality control of manufactured Al-MMC components in the automotive industry, to be explorer in the European FLAMINGo project (Fabrication of Lightweight Aluminium Metal Matrix Composites and Validation in Green Vehicles). This study is very significant because the NDT techniques present different probabilities of detection of the defects, principally of the microdefects.
Determining ultrasonic propagation effective properties in complex heterogeneous media through microstructure-scale simulation
Authors:   University Paris-Saclay, Dorval Vincent ,   Commissariat Energie Atomique (CEA), Leymarie Nicolas ,   Commissariat à l’Energie Atomique (CEA), Imperiale Alexandre ,   University Paris-Saclay, Demaldent Edouard ,   Electricité de France (EDF), Aghenzour Zakaria ,   Electricité de France (EDF), Lhuillier Pierre-Emile
Published: July 2023

Ray-based methods allow for fast computations of ultrasonic propagation in large components, and can be coupled with diffraction models to provide full simulations of NDE inspections. However, they do not account for complex interactions with highly heterogeneous propagation media, which can have a significant impact on inspection performances. In contrast, microstructure-scale finite element simulations consider these interactions but are too computationally intensive for large-scale simulations. The work presented in this communication aims at combining the advantages of these two approaches. On the one hand, finite element simulations for small volumes of the microstructure are used to determine parameters such as effective velocities, attenuations, and scattering coefficients. On the other hand, a ray-based model uses these data to compute wave propagation over distances that are large compared to both wavelengths and characteristic microstructure sizes. A dedicated simulation module has been implemented in a development version of the CIVA software. It generates random realizations of microstructures for given set of parameters, runs finite element computations, and post-processes their results to yield estimations of the properties of the macroscopic effective medium. The volumes considered by the finite element model are small enough to allow for 3D computations. Results were obtained for various types of microstructures, describing metals or concrete. This communication focuses on steel applications that were the focus of collaborative studies between CEA and EDF. The approach is promising, and contributes to bridging the gap between microstructure-scale modelling and larger scale simulations.
Layer thickness measurement of ceramic systems with a numerical model for flash thermography
Authors:   Siemens AG,  Corporate Technology (CT), Frisch Julia ,   Siemens Energy, Sripragash Letchuman ,   Siemens Corporate Technology, Goldammer Matthias ,   Technical University of Munich (TUM), Grosse Christian U.
Published: July 2023

Thermography is a non-destructive testing technique which is non-contacting as well as imaging and therefore advantageous for delicate materials. It is more widely used for qualitative evaluation but can also provide data for a quantitative analysis when the heat source is actively controlled. With flash thermography, fast diffusion or conduction processes can be monitored, providing an effective method for the inspection of metals and thin coatings. Ceramic layered systems are used as thermal barrier coatings, for example on turbine blades. Gas turbines with such blades can be operated at higher temperatures, which leads to an increase in efficiency. To fully exploit this advantage, the properties and thickness of the coating must be within a predefined parameter range. Due to the challenging and hard to monitor manufacturing process, the coating must be examined afterwards. With the help of a numerical model using a finite difference solution, multiple material parameters such as thermal conductivity and layer thickness can be determined simultaneously with nonlinear regression fitting. During the research presented herein, a four-stepped sample of ceramic coatings on an Inconel steel basis is examined and the thermographic data analysed. After the thermographic measurements, the sample was cut, embedded in resin, and polished. The scanning electron microscopy images and measurements serve as the reference values to compare the extracted parameters to.
Active thermography to look beneath the surface of a historic German aircraft
Authors:   Technical University of Munich (TUM), Frisch Julia ,   Deutsches Museum, Blaensdorf Catharina ,   Deutsches Museum, Hempfer Andreas ,   Deutsches Museum, Pamplona-Bartsch Marisa ,   Technical University of Munich (TUM), Grosse Christian U.
Published: July 2023

Thermography is a well-established non-destructive testing technique in materials research and defect detection. In addition, it is used on cultural heritage in the form of buildings and paintings. This contribution explores the utilisation of active thermography on an object of technical heritage – a historic aircraft of the Second World War, the Messerschmitt Me 163 b, as a part of an exhibition in the Deutsches Museum in Munich. Unfortunately, the appearances of many exhibits in museums have been altered before or during their time with the museum and are not in a historically accurate condition. Furthermore, the active service history is often not documented in detail or might have been lost. Both features are equally important in the presentation of information on a displayed item and destructive techniques cannot be employed on historic objects. Hence a non-destructive, non-contact way of examination was chosen in the form of thermography. With the help of phase analysis, flash thermography is also an invaluable tool for the evaluation of layered systems and can differentiate between paint layers. During the research presented herein, traces of abrasion and chemical stripping of older paint layers were visible. This complicates the compilation of sufficient information for a historically accurate restauration with any technique. Nonetheless, flash or pulsed thermography proves to be capable of finding not only identifying markings, defects, and different paint layers, but also the inner workings and substructure of the object under investigation.
Experiments with Near-Field Microwave Imaging for Powder Bed Fusion Metal Additive Manufacturing
Authors:   University of Lisbon, Barancos André ,   University of Lisbon, Macedo Victor ,   ISQ - Taguspark, Batalha Rodolfo L. ,   NOVA University of Lisbon, Machado Miguel A. ,   NOVA University of Lisbon, Santos Telmo G. ,   University of Lisbon, Rosado Luís S.
Published: July 2023

Experiments to evaluate the use of Near-Field Microwave (NFMW) imaging for the Powder Bed Fusion quality control are here reported. A NFMW sensor was employed together with general purpose instrumentation to perform measurements over a stainless steel 316 sample produced by laser PBF. Although with limited sensitivity, results showed that NFMW sensors can be used to evaluate the proper layer consolidation while relying on the electrical conductivity difference between powder and consolidated metal. Results also highlight the sensor high spatial resolution, well appreciated for PBF layer-wise imaging.
Evaluating Capacitive Imaging for Powder Bed Fusion Metal Additive Manufacturing
Authors:   University of Lisbon, Macedo Victor ,   University of Lisbon, Barancos André ,   NOVA University of Lisbon, Machado Miguel A. ,   Federal University of Pelotas, Santos Thiara ,   NOVA University of Lisbon, Santos Telmo G. ,   Instituto de Engenharia de Sistemas e Computadores, INESC-ID, Rosado Luís S.
Published: July 2023

This work evaluates the use of co-planar capacitive sensors to provide layer-wise imaging results for the Powder Bed Fusion quality control. A new sensor was designed together with a digital readout electronics which allowed for high-resolution localized measurements. The system was evaluated in different surface features produced by laser PBF with stainless steel 316 powder. Features were tested with and without the presence of the original powder with results showing that the powder presence masked the output for most of the features. This suggests that the ability of carrying charges within an alternating electrical field is similar between powder and the consolidated metal, and that, the concerning signal contribution is much higher than that caused by the conductivity difference between powder and consolidated metal.
Advanced Eddy Current Testing of Carbon Composites
Authors:   Eddyczech s.r.o., Rudolfova Marie
Published: July 2023

Carbon composites due to their specific properties find applications in various industries, especially in aerospace industry. Widely used carbon fibre reinforced polymers (CFRP) have already been applied even for the aircraft primary structures. The development of advanced diagnostic techniques that are able to easily detect and identify the degradation of the carbon fibre material is still a challenge for various NDT methods. This paper describes the possibility to apply eddy current (EC) for testing of carbon composite structures. Two types of eddy current probes were developed and tested with excellent results. The new conventional eddy current probes are able to reliably and easily detect surface and subsurface discontinuities such as delamination and thickness variation. The probe setting parameters are described for different types of carbon composites (type of matrix and reinforcement, layup). Precise settings are necessary for the successful eddy current testing. It was determined that reliable detection of a minimum surface defect size is Ø1.5 mm for specimens and that eddy currents are able to penetrate into a thickness up to approximately 4 mm depending on the type of carbon composite. Additionally, this paper describes the comparison of eddy current testing with ultrasonic phased array method (PAUT). Composite aircraft structures are very susceptible to impact damage usually detected using PAUT. Therefore, sensitivity and resolution analysis of impact damage detection was performed by means of these two methods. It was found out that the results are very similar to each other when standard pulse-echo technique of PAUT was used. This carbon composite eddy current testing could fully replace or complement other NDT methods such as visual or ultrasonic inspections. Also it could guarantee the product quality in production, aircraft maintenance and in the development of new aircraft structures.
Standard development for Eddy Current Arrays in lieu of Magnetic Particle Testing
Authors:   Eddyfi Technologies, Wassink Casper ,   Electric Power Research Institute (EPRI), Wolf Matthew ,   Eddyfi Technologies, Sirois Michael
Published: July 2023

The technology of Eddy Current Arrays has advanced considerably in recent years. In several trials, superior performance compared to magnetic particle testing was shown. In response, ASME has published new articles on Eddy Current Array (ECA) testing in the 2019 edition of the BPV, and IIW has started a working group to develop ISO standards for the use of eddy current array testing in lieu of magnetic particle testing. Significant interest has been indicated by stake holders, including manufacturers, end-users and regulators. In the paper, the work performed in the IIW working group will be presented. This includes a literature survey on the relative performance of eddy current array testing and magnetic particle testing. In particular, the performance in terms of probability of detection and characterization will be explored. The technical background of performance differences with conventional eddy current testing, magnetic particle testing and dye penetrant testing will be evaluated. Conclusions are drawn on the most important properties to be treated in a new ISO standard in the ISO 17635 framework. The scope of the IIW working group includes a general standard, a weld testing standard and acceptance criteria. Finally, the issues discussed in standard development will be presented and the resulting formulations explained. Comparisons will be made between the ASME and IIW/ISO resolutions.
Flaw Detection in Wire and Arc Additive Manufacturing Using In-Situ Wide Frequency Bandwidth Acoustic Pressure
Authors:   NOVA University of Lisbon, Ramalho André ,   NOVA University of Lisbon, Santos Telmo G. ,   Virginia Polytechnic Institute and State University (Virginia Tech), Bevans Benjamin ,   University of Nebraska, Smoqi Ziyad ,   Virginia Polytechnic Institute and State University (Virginia Tech), Rao Prahalad ,   NOVA University of Lisbon, Oliveira J. P.
Published: July 2023

Wire and arc additive manufacturing (WAAM) is an additive manufacturing (AM) process that can produce large metallic components with low material waste and high production rates. However, WAAM’s high deposition rates require high heat input which can result in potential defects such as pores, cracks, lack of fusion or distortion. For practical implementation of the WAAM process in an industrial environment it is necessary to ensure defects-free production. However, the NDT inspection using traditional NDT techniques (ultrasound, eddy currents, x-ray, for example) is a very demanding task, especially during part production. Therefore, reliable online NDT inspection and monitoring techniques are needed for the industrial spread of WAAM. The objective of this work is to detect flaw formation on WAAM produced parts using in-situ acquired acoustic data with a frequency bandwidth from 10 to 1MHz. WAAM parts were processed with deliberately introduced contaminations while its acoustic signal was obtained to correlate different signal characteristics with defects. To identify flaw formation, two distinct types of microphones were employed to acquire data from the same deposition process. The processing of the signal consisted of applying time and frequency domain techniques, namely, Power Spectral Density and Short Time Fourier Transform. The acoustic signatures obtained allowed for the differentiation between flawed and flaw free signals and for the spatial location of the contaminations. The acoustic signal acquired also showed that the data acquired by conventional microphones is not enough to fully characterize the acoustic spectrum emitted by the WAAM process. This work demonstrates the potential of acoustic data and signal processing in the online inspection of WAAM produced parts.
Formulation of a Mechanical Stress Dependent Macroscopic Magnetic Model for Incremental Permeability Simulation
Authors:   Altair France, Lombard Patrick ,   Ecole Normale Supérieure de Cachan, Hubert Olivier ,   Tata Steel, Van Den Berg Frenk
Published: July 2023

Electromagnetic based systems receive ever-growing interest for on-line assessment of steel strip properties for major manufacturers, especially when Advanced High Strength Steel (AHSS) products for automotive purposes are considered. Manufacturing AHSS need optimal control of the thermo-mechanical processing using in-line sensors for real time monitoring. IMPOC, 3MA and PropertyMon are some of the well-known electromagnetic sensors. Identification of a mechanical or metallurgical state from a magnetic signal is of great interest, requiring however sophisticated models to mimic the real behaviour and its sensitivity to many influencing parameters. Our paper presents a proposition to add the dependency of mechanical stress to the Jiles-Atherton hysteresis model. Experimental data consist of B(H) curves of carbon steels strips subjected to different levels of mechanical stress applied along the magnetic measurement direction. The JilesAtherton model has then been used to find out a set of stress-dependent coefficients. The variation of coefficients with stress is in close relationship with the variations of coercive field, remanent induction and permeability with stress. A coupled magneto-mechanical approach allows physics-based functions to be proposed to describe the evolution of JilesAtherton coefficients with stress. In this paper, experimental working conditions will be described, as well as the stressdependent Jiles-Atherton model. The model is finally implemented in FEM software, allowing more complex magneto-mechanical situations to be modelled. After matching with measurement, the new model is applied on 3MA modelling where magnetic transient analysis and magnetic AC steady state analysis are linked through incremental permeability.
How to Reach 100% Inspection Coverage of Aeroengine Fan Blades with a High Probability of Detection
Authors:   Evident Industrial (formerly Olympus Scientific Solutions), Grondin Etienne ,   Evident Europe GmbH, Raude Angelique
Published: July 2023

In aviation, quality is paramount to determine an aircraft’s airworthiness and keep personnel and passengers safe. Non-destructive testing (NDT) methods are largely used throughout an aircraft’s lifetime, including raw material selection, manufacturing, assembly, and in-service maintenance. As a key component of aircraft, engines are governed under strictly scheduled maintenance programs where they are dismantled and thoroughly inspected. Part of this global inspection concerns the individual verification of fan blades to assess the absence of flaws, such as surface cracks. Due to the complex geometry of fan blades, established methods such as penetrant testing (PT) and magnetic particle inspection (MPI) have been successfully used in past decades to detect surface-breaking flaws in fan blades. However, these techniques are complex to deploy and do not permit results traceability. As an alternative, eddy current (EC) technologies proved to be a good candidate to discriminate flaws as small as 1 mm long. Combining both conventional and eddy current array technology provides valuable information on the integrity of the component. Powered with the development of dedicated signal processing methods, the proposed solution helped to increase signal-tonoise ratio, avoiding any false calls. Once this was achieved, a careful study of the probe’s deployment and compliance with the various changes of geometries—from the blade’s surface to its edges and root, helped ensure optimal crack detection. Finally, recent advances in robotics enabled an automated inspection strategy to perform 100% coverage with high reproducibility and repeatability. This greatly improved the probability of detection of sub-millimeter surface-breaking cracks. This paper describes the study performed to assess the capability of eddy current solutions (conventional and advanced) to replace traditional methods of inspecting titanium fan blades. It also shows how dedicated signal processing enables increased probability of detection. The proposed approach to provide full coverage of the complex geometry and the associated developments are detailed. Finally, the paper presents an integration of the complete inspection technique in an automated system.
A Physics-informed Neural Network for Pulsed Thermography- Based Defect Detection
Authors:   National Tsing Hua University, Hsiao Tung-Yu ,   National Tsing Hua University, Yao Yuan
Published: July 2023

The non-destructive testing technique of pulsed thermography has been widely used in materials to detect defects due to its low cost, large detection area, and rapid implementation. After conducting experiments, data processing is often necessary to reduce the influences of noise and non-uniform backgrounds and highlight defect information. However, during the analysis, physical information is usually ignored. In addition to thermographic data analysis, numerical simulations are also popular for analytical studies based on physical information, but they don’t fully utilize the experimental data. To address this, a new method was proposed using a physics-informed neural network (PINN) for thermographic data processing. PINN combines the prediction capabilities of deep neural networks with physical laws presented as partial differential equations and boundary conditions, allowing for both experimental data and physics information to be utilized in modelling. In pulsed thermography, the heat transfer is governed by Fourier's law of heat conduction in a three-dimensional system. However, there is a lack of temperature measurements in the depth direction. The proposed method solves this problem by using collocation points generated from Latin hypercube sampling. The PINN model provides a good estimation of the backgrounds in the thermograms, and the features of surface/subsurface defects are highlighted by subtracting the estimated backgrounds from the original thermograms. In the case study, the performance of the proposed method was found to be effective.
Phased Array Ultrasonic Testing for Inspection of LNG Storage Tank
Authors:   Korea Institute of Material Science, Won Soonho ,   Korea Inspection & Engineering Co, Lim Sungjin ,   Korea Inspection & Engineering Co, Jeong Ingon ,   Korea Institute of Material Science, Lee Haksung
Published: July 2023

Liquefied natural gas (LNG) is liquefied at -162°C at atmospheric pressure and stored in

the inner shell. Due to the transport and storage characteristics of such low temperature

conditions, 9% high nickel steel, which shows excellent strength and toughness even at

low temperatures, is used for the inner wall. On the other hand, the base material of the

inner wall has a tempered martensite structure, whereas the weld metal has an Inconel- based austenite structure with high damping properties in acoustics. Also, the weld metal

is composed of an anisotropic structure completely different from the base material. These

are considered obstacles in non-destructive testing. We applied automated phased array

ultrasonic testing(PAUT) as a replacement of radiographic testing in inspection of LNG

storage tank. To obtain the reference value data, a reference specimen for each thickness

was prepared, and an automatic scanning device was designed and manufactured. Also, a

customized phased array(PA) probe was developed and applied. All parts are integrated

and operated as one system, and the data is analyzed and stored through an operating

program developed in-house. The current system has proven its performance through

field application to a much-improved level in the existing scanning device, probe and

application method. In conclusion, it was proved that our technology can be

commercialized by showing excellent detection ability.
Knowledge Sharing as a Central Idea of Open Science and NDT 4.0
Authors:   NDT.net, Diederichs Tamara ,   NDT.net, Diederichs Michelle ,   NDT.net, Diederichs Rolf
Published: July 2023

NDT 4.0 has become a buzz word in the world of NDT in recent years. At the same time, terms like open science, open access or open peer review cross our ways regularly and define present and future concepts to advance knowledge sharing in society. This article brings the concept of open science and NDT 4.0 together. While knowledge sharing as part of artificial intelligence and the internet of things are often in focus when talking about Industry 4.0 or NDT 4.0, this paper draws on the importance of knowledge sharing between humans as a substantial aspect of Industry 4.0, and more specifically NDT 4.0. Knowledge sharing between humans has especially become relevant with the introduction of the internet and the world wide web (www), but its importance cannot be disregarded in times where everybody is talking about technical developments, machine learning and artificial intelligence. On the contrary, sharing knowledge openly between humans remains central to advancing todays developments and innovation. The NDT community has had the benefit to share, create and exchange knowledge at an early stage of the internet through a unique platform that was established in 1996; NDT.net. After reviewing the concepts of open science and NDT 4.0, this paper illustrates how the NDT community has had the benefit of knowledge sharing since the early days of the internet through the establishment of NDT.net. This open access platform has been playing and continues to play a central role in advancing ideas of open science and NDT 4.0.
A High-Speed Ultrasound Full-Matrix Capture Acquisition System for Robotic Weld Inspection
Authors:   us4us Ltd., Lewandowski Marcin ,   us4us Ltd., Karwat Piotr ,   us4us Ltd., Jarosik Piotr ,   us4us Ltd., Rozbicki Jakub ,   us4us Ltd., Walczak Mateusz ,   Polish Academy of Sciences (PAN), Smach Hanna
Published: July 2023

Phased-Array Ultrasonic Technique is traditionally used for the non-destructive inspection of welds and supported by industrial-grade inspection equipment. FullMatrix Capture (FMC) with Total Focusing Method (TFM) provide new capabilities and multimodal imaging, but available commercial scanners have limitations in acquisition speed (30–300MB/s) and reconstruction speed. Our goal was to develop a solution for FMC acquisition that can be applied to high-speed robotized weld scanning (speed of 100 mm/s with a resolution of 1 mm). For FMC acquisition, we have applied a portable programmable ultrasound research system us4R-lite™ (us4us Ltd., Poland) in a 64:256 channel configuration and standard angled 32-element Phased-Array probes. The system can acquire and store raw RF or demodulated I/Q data at a speed of 2–6 GB/s, enabling real-time FMC at high speed. Data can be stored on a PC during scanning and processed by a high-performance GPU. We have successfully tested our experimental setup while scanning flat-section welds with a motorized scanner at a speed approaching 100 mm/s. The acquisition and processing software developed uses Nvidia CUDA on GPU and can manage real-time storage and scanning. Next, we are planning to integrate the solution into an industrialgrade high-speed FMC acquisition system with embedded GPU processing.
Study of the solidification behaviour of phase change materials by in-situ X-ray computed tomography
Authors:   Lucerne University of Applied Sciences and Arts (HSLU), Martinez-Garcia Jorge ,   Lucerne University of Applied Sciences and Arts (HSLU), Gwerder Damian ,   Lucerne University of Applied Sciences and Arts (HSLU), Guarda Dario ,   Lucerne University of Applied Sciences and Arts (HSLU), Fenk Benjamin ,   Lucerne University of Applied Sciences and Arts (HSLU), Stamatiou Anastasia ,   Lucerne University of Applied Sciences and Arts (HSLU), Wortlitscheck Jörg ,   Lucerne University of Applied Sciences and Arts (HSLU), Schuetz Philipp
Published: July 2023

Calcium chloride hexahydrate (CaCl2.6H2O) is a stablished inorganic salt hydrate-based phase change material (PCM) with interesting properties for low temperature latent heat thermal energy storage (LHTES) applications. However, its phase transition during melting and solidification exhibits a complex behaviour with supercooling and phase segregation effects, which critically limit their practical applications. Experimental approaches enabling tracking of the solidification process in this PCM are thus crucial for a deeper understanding of these adverse effects and to design efficient LHTES. In this study, a novel method based on dynamic X-ray computed tomography (XCT) is used to monitor the solidification process in CaCl2.6H2O through sequences of XCT images. The method was tested with a sample of 60g of CaCl2.6H2O with density of 1.71 g/cm3 and purity higher than 98%. The results reveal that solidification of CaCl2.6H2O occurs through the fusion of crystalline structures initially appearing at the side and the bottom surfaces of the sample which grow over time. In the experiment performed, the solidification process is found to be incomplete, which is frustrated after 385 min of starting the solidification. This frustration was preceded by a change in the total solidification rate which is here estimated from the transient liquid volume fraction curve computed via image processing analysis. Quantitative estimation for the crystals size is also reported.
Wheel and axle defect detection based on deep learning
Authors:   Southwest Jiaotong University, Peng Jian ping ,   Southwest Jiaotong University, Zhang Qian ,   Tie'an Technology Co., Ltd., Zhao Bo
Published: July 2023

With technological innovations in the world of high-speed railways, railways have become an indispensable and important part of life. As a key part of the train, the safety of the wheels and axles cannot be ignored. Industry often uses non-destructive testing (NDT) methods, and because of the special structure of wheels and axles, we commonly use phased-array ultrasonic testing. However, the disadvantage is that ultrasonic inspection methods rely too much on the intuition of skilled workers and as the workload increases, a large amount of data is not used effectively, which can easily lead to safety hazards. To deal with these issues, an efficient detection method emerges as the times require. we collected ultrasound-based B-scan defect data for wheels and axles, by expert manual annotation to establish a database of various types of defects in wheels and axles of existing trains. By using the improved YOLO-v5-based algorithm for training validation and testing, improving the feature extraction layer and adding a small target detection layer for difficult defects. Finally, by adding an attention mechanism to improve the training accuracy and using active learning strategies for data enhancement to make it more applicable to ultrasound images, the experiments significantly improved detection efficiency and stability, with a high defect detection rate and a significantly decreased false alarm rate. The algorithm has good performance with laboratory data. The algorithm has good performance in laboratory data and can meet the application requirements in the actual wheel and axle inspection data, we tested more than 3000 different pictures which are all from the real data collected by ultrasonic testing, with the defect detection alarms reaching 100%, detection speed reaching real-time detection, and false alarms being controlled to within 2%. More importantly, with the self-upgraded of algorithm and new data collection, the detection efficiency will improve gradually.
Total Focusing Method (TFM) and Phase Coherence Imaging (PCI) applied to various industrial cases
Authors:   Eddyfi Technologies, Reverdy Frederic ,   Eddyfi Technologies, Hillman Paul ,   Eddyfi Technologies, Maes Guy
Published: July 2023

Imaging techniques based on ultrasonic Total Focusing Method (TFM1) are more and more applied for industrial applications. Adoption of the technique has been made easier with the publication of the revised ASME V and ISO 23864 and 23865 standards. TFM is an inspection technique that involves two steps: the first one is the data acquisition process called Full Matrix Capture (FMC) and the second one is the data reconstruction itself called TFM. TFM is able to focus the energy at every pixel within a region of interest providing a high-resolution image. Efforts have been made to improve the productivity of the technique using various excitation modes such as Plane Wave Imaging (PWI) to reach scanning speeds comparable to standard phased-array inspections while maintaining code compliance. While TFM is based on the extraction of the amplitudes of the FMC matrix, another technique called Phase Coherence Imaging (PCI2) uses the phase information from those signals. The PCI image shows high values when all the elements contribute in phase. This is the case for small diffractors that tend to send energy in all directions such as small cracks (HTHA, porosities…), tips from cracks and grain noise. At the opposite, specular echoes tend to be minimized since few elements contribute to the echo. In this paper, we’ll show the advantages of both techniques on various industrial cases.
Magnetic crawler for welds Visual Testing,
based on 3D profilometry and 2D image processing
Authors:   Swiss Safety Center AG, Induti Marco ,   Swiss Safety Center AG, Romito Carlo ,   Swiss Safety Center AG, Scaccabarozzi Luca
Published: July 2023

To ensure the satisfactory performance of a welded structure, the quality of the welds must be determined by adequate testing procedures. During Visual Testing (VT), the weld is examined through the eyes of an inspector to determine surface discontinuities. Although this is commonly considered the easiest, quickest, and least expensive type of inspection, it has some limitations: a certified inspector shall always be on site to perform the test, making it strongly dependant on his experience, knowledge and current environmental conditions. In addition, there is no possibility to record inspection data except standard pictures and comments to be added to inspection reports. Modern technology brings novel solutions for quality assurance. This article describes a powerful tool which can improve the reliability of VT that combines precise laser measurements, image processing and data cloud computing. A portable magnetic crawler has been developed using a Raspberry Pi SBC, a smart profile sensor and a 5 MPix industrial colour camera in order to gather both weld 3D point cloud and surface pictures. Laser triangulation and processing power directly integrated on board allow an easy weld profile measurement. Undercuts, reinforcement excess, spatters, hi-low are precisely detected and sized by the laser sensor while integrated 2D camera records and analyses surface features such contaminations, corrosion, and weld discoloration. The point cloud weld reconstruction is realized stitching together 2D profile data at a fixed interval that can range up to a hundredth of a millimetre with a spatial resolution up to 50um. Inspected weld is fully digitalized in the form of 3D object together with a set of numerical features, data are securely stored in a local flash memory and automatically synchronized with cloud platform for remote data visualization. Automatic weld assessment can also be applied using cloud computing and artificial intelligence (AI) algorithms together with deep learning tools. The combination of images, 3D models, measurements, and other evaluable features all together in the same digital platform definitely enriches the weld assessment making it quicker and reliable with the support of AI, it gives the possibility of remote visual inspection, it ensures a flawless workflow where visual inspection data are stored in a dedicated platform and can be accessed at any moment by stakeholders.
Total Focusing (TFM) for the Ultrasonic Testing (UT) of drawn arc stud welding
Authors:   Swiss Safety Center AG, Romito Carlo ,   Swiss Safety Center AG, Hörtnagl Arnulf ,   Swiss Safety Center AG, Induti Marco
Published: July 2023

This article describes the results obtained applying ultrasonic testing (UT) with phased arrays (PAUT) using full matrix capture (FMC) and total focusing method (TFM) for the inspection of drawn arc stud welding. Weld studs are usually directly applied on the top of a metal slab using a dedicated welding gun. This procedure involves heating the end tip of the stud using a strong electric arc created by a positive electric current. This welding procedure shall comply to various normative requirements, but on the other side there is not a clear reference to any applicable non-destructive method (NDT) to control the quality of the weld seam. Shear connectors are normally used in concrete/steel composite structures to allow the combined action of the concrete slab and the steel profile thereby increasing both the stiffness and strength of the structure. Flaws in this connection would result in severe bending and cracking of the entire structure. This article proposes an advanced UT method to inspect the weld between shear connections and metal slab using FMC. Data acquired with FMC are processed by TFM algorithms improving image resolution, signal to noise performances and allowing 3D data imaging. The combined use of PAUT searching units and signal processing with high resolution measurement shows a great potential in industrial NDT applied to civil engineering, resulting in a more effective, reliable, and faster inspection methodology than many other methods, such as radiographic testing (RT).