TY - GEN A1 - Bühling, Benjamin T1 - Acoustic and flow data of an ultrasonic fluidic switch and an ultrasonic piezoelectric transducer N2 - This dataset contains acoustic and flow data of an ultrasonic fluidic switch, which have been acquired using a microphone, a hot-wire anemometer and a pitot tube. Furthermore, acoustic data of a commercial piezoelectric transducer is provided. KW - Fluidics KW - Air-coupled ultrasound KW - Ultrasound KW - Non-destructive testing KW - Acoustic-flow interaction KW - Piezoelectric transducer PY - 2020 DO - https://doi.org/10.7910/DVN/OQYPC9 PB - Harvard College CY - Cambridge, MA, USA AN - OPUS4-52392 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bühling, Benjamin A1 - Schweitzer, T. A1 - Maack, Stefan A1 - Strangfeld, Christoph T1 - Influence of operating conditions on the fluidic ultrasonic transducer signal N2 - While contact and immersion ultrasonic testing are established methods in non-destructive testing (NDT), generating high power air-coupled ultrasound remains a challenging task. Solutions often involve setups that are restricted to lab environments. When field measurements are required, such as in NDT for civil engineering, a handy, robust and safe transducer is needed. For this purpose, an ultrasonic transducer based on a fluidic switch has been developed. A sonic air flow inside the device is switched rapidly so that an ultrasonic signal is generated. Both theory and previous flow simulations suggest that the control flow pressure ramp has only little influence on the switching time of the device. This publication gives an overview over the operating principle of the fluidic ultrasonic transducer and investigates the influence of control tube length and pulsing repetition rate on the ultrasonic pressure amplitude. High repetition rates are found to reduce the signal amplitude, whereas long tubing has only little negative influence on the amplitude while improving signal quality. T2 - 47. Jahrestagung für Akustik (DAGA 2021) CY - Vienna, Austria DA - 15.08.2021 KW - Ultrasound KW - Non-destructive testing KW - Fluidic devices PY - 2021 UR - https://pub.dega-akustik.de/DAGA_2021 SN - 978-3-939296-18-8 SP - 48 EP - 51 CY - Berlin, Germany AN - OPUS4-53493 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bühling, Benjamin T1 - Recent Developments of Fluidic Ultrasonic Transducers at BAM N2 - Ultrasonic measurement technology has become indispensable in NDT. In order to reduce measurement time and extend the application to other materials, contactless ultrasound is the subject of many different research groups. Department 8 has been researching successfully in this field for years. A novel approach is based on so-called fluidic devices. These devices can be used to perform binary logic operations with the help of natural flow instabilities. Hence the abbreviated name, Fluidic (FLUID+LogIC). Only a pressure reservoir of the used fluid is required as energy supply. This enables the production of very robust actuators that generate ultrasonic signals in an extremely energy efficient way. The presentation includes the research results of the ZIM innovation project OsciCheck. The original idea will be presented and its application on different building materials is validated. Beyond this, the possible application areas are much larger and a detailed outlook is given to discuss the future potential of fluidic ultrasonic actuators. T2 - Abteilungsseminar Abteilung 8 CY - Berlin, Germany DA - 23.09.2021 KW - Uultrasound KW - Non-destructive testing KW - Fluidic devices KW - Hydrogen KW - Ranging KW - Harsh environments PY - 2021 AN - OPUS4-53356 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bühling, Benjamin T1 - Influence of Operating Conditions on the Fluidic Ultrasonic Transducer Signal N2 - Motivation: • Air-coupled ultrasound (AC-US) enables faster measurements in non-destructive testing for civil engineering • Current state of the art: piezo and capacitive transducers are mostly used for AC US • Currently >99.9% sound intensity loss due to impedance mismatches Innovation: • Fluidic transducers generate US (30-60 kHz) by rapid switching of a supersonic jet • Fluidic transducers rely on external components such as solenoid valves and tubing --> How do repetition time and tube length influence the signal? T2 - DAGA 2021 CY - Vienna, Austria DA - 15.08.2021 KW - Ultrasound KW - Non-destructive testing KW - Fluidic devices PY - 2021 AN - OPUS4-53408 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nicolicea, Alberto A1 - Oliveros-Mata, E. S. A1 - Zabila, Y. A1 - Makarov, D. A1 - Melzer, Michael A1 - Pelkner, Matthias T1 - Flexible anisotropic magnetoresistive sensors for novel magnetic flux leakage testing capabilities N2 - Rigid magnetic field sensors such as anisot Hall sensors have been used for years and have become industry standard for electromagnetic non-destructive testing (NDT). Recent technological developments in the field of flexible electronics allow for the fabrication of reshapeable magnetic field sensors on flexible substrates via thin-film deposition or printing. The magnetic properties of these sensors have comparable characteristics to industry-standard rigid magnetic field sensors, with the added ability of adapting to the surface of complex components and scanning in contact with the sample surface. This improves defect detectability and magnetic signal strength by minimizing the scanning lift-off (LO) distance. In this article flexible AMR sensors mounted on a rotative mechanical holder were used to scan a semi-circular ferromagnetic sample with 3 reference defects via magnetic flux leakage (MFL) testing, thus demonstrating the applicability of this type of sensors for the scanning of curved samples. In order to benchmark the performance of these sensors in comparison to industry standard rigid magnetic field sensors, a ferromagnetic sample with 10 reference defects of different depths was scanned employing flexible AMR and rigid GMR sensors. Defects with depths ranging from 110 μm up to 2240 μm were detected with an signal-tonoise ratio (SNR) of 2.7 up to 27.9 (for flexible AMR sensors) and 6.2 up to 72.3 (for rigid GMR sensors), respectively. A 2D magnetometer mapping of the sample with a spatial scanning step of 10 × 50 μm2 (flexible AMR) and 16 × 100 μm2 (rigid GMR) was obtained. The results show that this type of sensor can be used for high-resolution and high-detail mapping of defects on the surface of planar and non-planar ferromagnetic samples since the scanning lift-off distance is equal to the substrate thickness of 20 μm for in-contact scanning. The SNR comparison between flexible and rigid sensors shows that the performance of the flexible AMR sensors employed is not very far behind the performance of the rigid GMR sensors used. KW - Flexible magnetic field sensors KW - Non-destructive testing KW - Magnetic flux leakage KW - Thin film sensor fabrication KW - Defect detection PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-603931 DO - https://doi.org/10.1016/j.ndteint.2024.103160 SN - 0963-8695 VL - 146 SP - 1 EP - 15 PB - Elsevier CY - Amsterdam AN - OPUS4-60393 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Nicolicea, Alberto A1 - Oliveros-Mata, E. S. A1 - Makarov, D. A1 - Melzer, Michael A1 - Pelkner, Matthias T1 - Flexible anisotropic magnetoresistive sensors for novel eddy current testing applications N2 - The standard method for eddy current testing (ET) of conductive materials relies on using rigid coils. In recent years magnetoresistive (MR) sensors in combination with an excitation wire have become a promising candidate for this application since it would increase the spatial resolution. New developments in flexible electronics have enabled the production of flexible sensors with the novel capability of scanning samples in conformal contact with the surface. In this article flexible anisotropic magnetoresistive (AMR) sensors were used in combination with a thin induction wire to perform eddy current testing of a curved aluminum sample with several defects imprinted on its surface. To benchmark the performance of this new method, a flat sample with reference defects of various dimensions was also scanned using flexible AMR sensors, inductive coils and rigid giant magnetoresistive (GMR) sensors. The results show that this new method of using flexible magnetic field sensors coupled with an excitation wire can easily be applied to the scanning of curved samples, while in the benchmark test employing the flat sample, the performance is not far behind more conventional techniques, with defects with depths down to 30 μm and widths down to 400 μm being detectable with an SNR of 3 (signal magnitude) and 8 (signal phase shift) at the excitation frequency of 50 kHz, and defects with depths down to 30 μm and widths down to 600 μm being detectable with an SNR of 10 (signal magnitude) and 17 (signal phase shift) at 260 kHz. KW - Magnetic field sensors KW - Flexible magnetic field sensors KW - Flexible electronics KW - Non-destructive testing KW - Eddy current testing KW - Thin film sensor fabrication KW - Defect detection KW - Magnetism PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-634325 DO - https://doi.org/10.1016/j.measurement.2025.117340 SN - 1873-412X VL - 253, Part A SP - 1 EP - 15 PB - Elsevier CY - Amsterdam AN - OPUS4-63432 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lecompagnon, Julien A1 - Rooch, Ludwig A1 - Hassenstein, Christian A1 - Ziegler, Mathias ED - Sakagami, T. ED - Inoue, H. T1 - Total Focusing in the Virtual Wave Domain: 3D Defect Reconstruction Using Spatially Structured Laser Heating N2 - Classical active thermographic testing of industrial goods has mostly been limited to generating 2D defect maps. While for surface or near-surface defect detection, this is a desired result, for deeply buried defects, a 3D reconstruction of the defect geometry is coveted. This general trend can also be well observed in widely used NDT methods (radiography, ultrasonic testing), where the progression from 2D to 3D reconstruction methods has already made profound progress (CT, UT phased array transducers). Achieving a fully 3D defect reconstruction in active thermographic testing suffers from the diffusive nature of thermal processes. One possible solution to deal with thermal diffusion is the application of the virtual-wave concept, which, by solving an inverse problem, allows the diffusiveness to be extracted from the thermographic data in the post-processing stage. What is left follows propagating-wave physics, enabling the usage of well-known algorithms from ultrasonic testing. In this work, we present our progress in the 3D reconstruction of deeply buried defects using spatially structured laser heating in conjunction with applying the well-known total focusing method (TFM) in the virtual-wave domain. T2 - 18th International Workshop on Advanced Infrared Technology and Applications (AITA 2025) CY - Kobe, Japan DA - 15.09.2025 KW - Non-destructive testing KW - Virtual wave concept KW - Laser thermography KW - Thermal thomography PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-641463 DO - https://doi.org/10.3390/proceedings2025129054 VL - 129 IS - 1 SP - 1 EP - 5 PB - MDPI CY - Basel AN - OPUS4-64146 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Lecompagnon, Julien T1 - Total Focusing in the Virtual Wave Domain: 3D Defect Reconstruction using spatially structured Laser Heating N2 - Classical active thermographic testing of industrial goods has mostly been limited to generating 2D defect maps. While for surface or near-surface defect detection, this is a desired result, for deeply buried defects, a 3D reconstruction of the defect geometry is coveted. This general trend can also be well observed in widely used NDT methods (radiography, ultrasonic testing), where the progression from 2D to 3D reconstruction methods has already made profound progress (CT, UT phased array transducers). Achieving a fully 3D defect reconstruction in active thermographic testing suffers from the diffusive nature of thermal processes. One possible solution to deal with thermal diffusion is the application of the virtual-wave concept, which, by solving an inverse problem, allows the diffusiveness to be extracted from the thermographic data in the post-processing stage. What is left follows propagating-wave physics, enabling the usage of well-known algorithms from ultrasonic testing. In this work, we present our progress in the 3D reconstruction of deeply buried defects using spatially structured laser heating in conjunction with applying the well-known total focusing method (TFM) in the virtual-wave domain. T2 - 18th International Workshop on Advanced Infrared Technology and Applications (AITA 2025) CY - Kobe, Japan DA - 15.09.2025 KW - Infrared thermography KW - Non-destructive testing KW - NDT KW - Total focussing method PY - 2025 AN - OPUS4-64145 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Fontoura Barroso, Daniel A1 - Epple, Niklas A1 - Niederleithinger, Ernst T1 - A Portable Low-Cost Ultrasound Measurement Device for Concrete Monitoring N2 - This paper describes a new ultrasonic measuring device called “W-Box”. It was developed based on the requirements of the DFG Forschergruppe (research unit) CoDA for a portable device for monitoring of concrete specimens, models and actual structures using embedded ultrasonic transducers as well as temperature and humidity sensors. The W-Box can send ultrasonic pulses with a variable frequency of 50–100 kHz to one selectable transducer and records signals from up to 75 multiplexed channels with a sample rate of 1 MHz and a resolution of 14 bits. In addition, it measures temperature and humidity with high accuracy, adjustable amplification, restarts automatically after a power failure and can be fully controlled remotely. The measured data are automatically stored locally on-site data quality checks and transferred to remote servers. The comparison of the W-Box with a laboratory setup using commercial devices proves that it is equally reliable and precise, at much lower cost. The W-Box also shows that their measurement capacities, with the used embedded ultrasonic transducers, can reach above 6 m in concrete. KW - Low-cost KW - Coda wave interferometry KW - Ultrasound KW - IoT KW - Non-destructive testing PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-546756 DO - https://doi.org/10.3390/inventions6020036 SN - 2411-5134 VL - 6 IS - 2 SP - 1 EP - 17 PB - MDPI CY - Basel, Switzerland AN - OPUS4-54675 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maack, Stefan A1 - Küttenbaum, Stefan A1 - Bühling, Benjamin A1 - Niederleithinger, Ernst T1 - Low frequency ultrasonic dataset for pulse echo object detection in an isotropic homogeneous medium as reference for heterogeneous materials in civil engineering N2 - The dataset presented contains ultrasonic data recorded in pulse echo mode. The investigated specimen is made of the isotropic homogeneous material polyamide and has a drill hole of constant diameter running parallel to the surface, which was scanned in a point grid using an automatic scanner system. At each measuring position, a pitch-catch measurement was performed using a sampling rate of 2 MHz. The probes used are arrays consisting of a spatially separated receiving and in-phase transmitting unit. The transmitting and receiving sides each consist of 12 point-shaped single probes. These dry-point contact (DPC) probes operate according to the piezoelectric principle at nominal frequencies of 55 kHz (shear waves) and 100 kHz (longitudinal waves), respectively, and do not require a coupling medium. The measurements are performed with longitudinal (100 kHz) and transverse (55 kHz) waves with different geometric orientations of the probe on the measurement surface. The data presented in the article provide a valid source for evaluating reconstruction algorithms for imaging in the low-frequency ultrasound range. KW - Non-destructive testing KW - Ultrasound KW - Pulse-echo method KW - Reference material KW - Reconstruction algorithm KW - Validation PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-547326 DO - https://doi.org/10.1016/j.dib.2022.108235 VL - 42 SP - 1 EP - 11 PB - Elsevier Inc. AN - OPUS4-54732 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Stefan A1 - Küttenbaum, Stefan A1 - Niederleithinger, Ernst T1 - Practical procedure for the precise measurement of geometrical tendon positions in concrete with ultrasonic echo N2 - Existing concrete structures were usually designed for lifetimes of several decades. The current and urgently required efforts to increase sustainability and protect the environment will likely result in extended service lives up to 100 years. To achieve such objectives, it is required to assess structures over their entire lifecycles. Non-destructive testing (NDT) methods can reliably support the assessment of existing structures during the construction, operational, and decommissioning phases. One of the most important and safety-relevant components of a prestressed concrete structure are the tendons. NDT methods such as the ultrasonic echo method are suitable for both the detection and the localization of the tendons, i.e., the measurement of their geometrical position inside the component. The uniqueness of structures, concrete heterogeneity, and varying amounts of secondary components such as the reinforcement represent obstacles in the application of these methods in practice. The aim of this contribution is to demonstrate a practicable procedure, that can be used in the field to determine the parameters required for the measuring data analysis without extensive knowledge about the investigated components. For this purpose, a polyamide reference specimen is used to show which steps are required to obtain reliable imaging information on the position of tendons from the measurement data. The procedure is then demonstrated on a concrete test specimen that covers various relevant and practice-oriented test scenarios, such as varying tendon depths and component thicknesses. T2 - International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR 2022) CY - Cape Town, South Africa DA - 03.10.2022 KW - Validation KW - Non-destructive testing KW - Ultrasonic KW - Reconstruction KW - Concrete KW - Tendon duct PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-559979 DO - https://doi.org/10.1051/matecconf/202236403007 SN - 2261-263X SP - 1 EP - 8 AN - OPUS4-55997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maack, Stefan A1 - Küttenbaum, Stefan A1 - Bühling, Benjamin A1 - Borchardt-Giers, Kerstin A1 - Aßmann, Norman A1 - Niederleithinger, Ernst T1 - Low frequency ultrasonic pulse-echo datasets for object detection and thickness measurement in concrete specimens as testing tasks in civil engineering N2 - The dataset contains raw data gathered with the ultrasonic pulse-echo method on concrete specimens. The surfaces of the measuring objects were automatically scanned point by point. Pulse-echo measurements were performed at each of these measuring points. The test specimens represent two typical testing tasks in construction industry: the detection of objects and the determination of dimensions to describe the geometry of components. By automating the measurement process, the different test scenarios are examined with a high repeatability, precision and measuring point density. Longitu- dinal and transversal waves were used and the geometrical aperture of the testing system was varied. The low-frequency probes operate in a range of up to approximately 150 kHz. In addition to the specification of the geometrical dimensions of the individual probes, the directivity pattern and the sound field characteristics are provided. The raw data are stored in a universally readable format. The length of each time signal (A-scan) is two milliseconds and the sampling rate is two mega-samples per second. The provided data can be used for comparative studies in signal analysis, imag- ing and interpretation as well as for evaluation pur- poses in different, practically relevant testing scenarios. KW - Validation KW - Puls-echo method KW - Ultrasonic KW - Non-destructive testing KW - SAFT KW - Reconstruction algorithm PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-575185 DO - https://doi.org/10.1016/j.dib.2023.109233 SN - 2352-3409 VL - 48 SP - 1 EP - 16 PB - Elsevier Inc. AN - OPUS4-57518 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Timofeev, Juri A1 - Azari, H. A1 - Satyanarayana, R. T1 - Controlled Creating of Delaminations in Concrete for Nondestructive Testing N2 - Locating and sizing delaminations is a common inspection task in the maintenance and quality control of construction and rehabilitation. Their detection is an important area of application of nondestructive testing in civil engineering (NDT-CE). To improve this application, NDT test systems and test solutions must be compared, for which specimens containing well-defined delaminations are needed to serve as a reference. Currently, there are no widely accepted procedures available for creating such flaws locally and reproducibly. This study presents procedures for creating artificial delaminations repeatably and as close as possible to natural delaminations. To produce the discontinuities only substances were used which can occur in concrete components and do not affect the application of NDT-CE methods. Ultrasonic pulse-echo (UPE) was used to test the flaws in the specimens. The delaminations were created by applying expansive mortar in prepared through holes. Three specimens with two delaminations each were built and tested using UPE. KW - Concrete KW - Reference KW - Delamination KW - Test specimen KW - Non-destructive testing PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-595201 DO - https://doi.org/10.1007/s10921-023-01044-7 SN - 0195-9298 VL - 43 IS - 1 SP - 1 EP - 13 PB - Springer Science and Business Media LLC AN - OPUS4-59520 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lay, Vera A1 - Baensch, Franziska A1 - Skłodowska, Anna A1 - Fritsch, Tobias A1 - Stamm, Michael A1 - Prabhakara, Prathik A1 - Johann, Sergej A1 - Sturm, Patrick A1 - Kühne, Hans-Carsten A1 - Niederleithinger, Ernst T1 - Multi–sensory Monitoring and Non–destructive Testing of New Materials for Concrete Engineered Barrier Systems N2 - The crucial part of nuclear waste storage is the construction of sealing structures made of reliable, safe and well–understood materials. We present an extended analysis of long-term multi–sensory monitoring and non–destructive testing (NDT) inspection of two laboratory specimens aiming at potential materials for sealing structures for nuclear waste repositories. Specimens with a volume of 340 litres made from newly developed alkali–activated materials (AAM) and established salt concrete (SC) were analysed using embedded acoustic emission and wireless radio-frequency identification (RFID) sensors, ultrasonic echo imaging, active thermography, and X–ray computed tomography. The monitoring analysis showed lower heat of reaction and 50% less acoustic emission events in AAM compared to SC. However, due to the surface effects of the AAM material, the number of acoustic emission events increased significantly after approximately two months of monitoring. Subsequently performed NDT inspections reliably located embedded sensors and confirmed the absence of major cracks or impurities. The presented laboratory results show the feasibility and potential of comprehensive NDT monitoring and inspection to characterise cementitious and alternative materials as well as the need for multi–parameter long–term monitoring. Thus, our study demonstrates that tailored NDT investigations will help to develop safe sealing structures for nuclear waste repositories. KW - Radioactive waste KW - Barrier KW - Concrete KW - AAM KW - Non-destructive testing PY - 2024 DO - https://doi.org/10.3151/jact.22.516 SN - 1347-3913 VL - 22 IS - 9 SP - 516 EP - 529 PB - Japan Concrete Institute AN - OPUS4-61461 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bahrami Eskandari, Ardalan A1 - Küttenbaum, Stefan T1 - NDT Data-Supported Structural Reassessments based on Regression Relations in Measuring Data Analysis N2 - Non-destructive Testing (NDT) provides valuable data about structural elements, supporting the assessment of existing infrastructures without incurring additional structural damage from inspections. Simultaneously, the uncertainty in measurement, which quantifies the quality of measurement results, plays a crucial role in decisions aimed at, e.g., optimizing maintenance strategies, rehabilitation works and Structural Health Monitoring (SHM) implementations. The Guide to the Expression of Uncertainty in Measurement (GUM) framework has already been considered for non-destructive concrete testing. Regarding that, extensive measurements with sophisticated scopes need to be conducted by experts as an obligatory process. This study illustrates how NDT results describing the inner structure of a concrete element can effectively support the reassessment of bridges in operation. To achieve this, the study considers the various measurable positions of the resisting longitudinal tendons of a bridge structure to investigate the displacement change under dynamic service loads. Furthermore, this study aims to simplify and optimize existing NDT data analysis procedures by employing regression analysis, enabling the detection of structural features. This regression analysis yields a modifier for determining the correct depth of an object within the structural element. The method is validated through laboratory experiments, including the use of an ultrasonic measurement system. As a result, it provides unbiased and accurately measured results, while ensuring that the measurement data can remain uncorrelated. Major advantages include efficient computation, a wider scope, and avoiding redundant information about the measuring process. The findings demonstrate that employing the proposed NDT analysis method, with its enhanced practicability, can significantly augment the efficiency of NDT data-supported structural reassessments across various scenarios. T2 - EWSHM 2024 CY - Potsdam, Germany DA - 10.06.2024 KW - Existing structures KW - Non-destructive testing KW - Practicality measurement KW - Bridge reassessment KW - Statistical analysis PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-604825 DO - https://doi.org/10.58286/29714 SN - 1435-4934 SP - 1 EP - 9 PB - NDT.net AN - OPUS4-60482 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - News from NDT@BAM N2 - The presentation summarizes some recent research at BAM in the field of NDT in civil engineering. the firste xample decribes lab experiments on the degardation of concrete during tunnel fires. Radar measuremenst were sucessfully used to detect interior damage. The second example decribes the first ever experiment on using muon imaging to evaluate concrete constructions. T2 - TRB 100th Annual Meeting, Subcommittee AKB40(1) CY - Online meeting DA - 05.01.2021 KW - Non-destructive testing KW - Civil engineering KW - Tunnel fire KW - Radar KW - Muon imaging PY - 2021 AN - OPUS4-52053 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liao, Chun-Man A1 - Hille, Falk A1 - Fontoura Barroso, Daniel A1 - Niederleithinger, Ernst ED - Papadrakakis, M. ED - Fragiadakis, M. T1 - Monitoring of a prestressed bridge model byultrasonic measurement and vibration recordings N2 - The aim of this work is to improve the current structural health monitoring (SHM) methods for civil structures. A field experiment was carried out on a two-span bridge with a built-in un-bonded prestressing system. The bridge is a 24-metre long concrete beam resting on three bear-ings. Cracks were formed subsequently when a prestressing force of 350 kN was changed to 200 kN, so that different structural states could be demonstrated. The structural assessment of this reference bridge was accomplished by the non-destructive testing using ultrasonic devices and vibration measurements. The ultrasonic velocity variations were investigated by using the coda wave interferometry method. The seismic interferometry technique was applied to the vi-bration recordings to reconstruct the wave propagation field in the bridge. This investigation shows that the wave velocity is sensitive to the current structural state and can be considered as the damage indicator. Overall, the implementation of coda cave interferometry and seismic interferometry technique facilitates structural health monitoring (SHM) in civil engineering. T2 - COMPDYN 2021 8th ECCOMAS Thematic Conference on Computational Methods in Structural Dynamics and Earthquake Engineering CY - Online meeting DA - 28.06.2021 KW - Structural health monitoring KW - Non-destructive testing KW - Coda wave interferometry KW - Seismic interferometry KW - Ultrasonic measurement KW - Prestress PY - 2021 SP - 1 EP - 9 PB - European Community on Computational Methods in Applied Sciences (ECCOMAS) AN - OPUS4-52957 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Stefan T1 - Practical procedure for the precise measurement of geometrical tendon positions in concrete with ultrasonic echo N2 - Existing concrete structures were usually designed for lifetimes of several decades. The current and urgently required efforts to increase sustainability and protect the environment will likely result in extended service lives up to 100 years. To achieve such objectives, it is required to assess structures over their entire lifecycles. Non-destructive testing (NDT) methods can reliably support the assessment of existing structures during the construction, operational, and decommissioning phases. One of the most important and safety-relevant components of a prestressed concrete structure are the tendons. NDT methods such as the ultrasonic echo method are suitable for both the detection and the localization of the tendons, i.e., the measurement of their geometrical position inside the component. The uniqueness of structures, concrete heterogeneity, and varying amounts of secondary components such as the reinforcement represent obstacles in the application of these methods in practice. The aim of this contribution is to demonstrate a practicable procedure, that can be used in the field to determine the parameters required for the measuring data analysis without extensive knowledge about the investigated components. For this purpose, a polyamide reference specimen is used to show which steps are required to obtain reliable imaging information on the position of tendons from the measurement data. The procedure is then demonstrated on a concrete test specimen that covers various relevant and practice-oriented test scenarios, such as varying tendon depths and component thicknesses. T2 - International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR 2022) CY - Cape Town, South Africa DA - 03.10.2022 KW - Validation KW - Non-destructive testing KW - Ultrasonic KW - Reconstruction KW - Concrete KW - Tendon duct PY - 2022 AN - OPUS4-55999 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maack, Stefan T1 - Recent advances in (ultra)sonic active and passive monitoring of reinforced and prestressed concrete structures N2 - In addition to already established structural monitoring methods such as deformation, inclination or strain gauges or acoustic emission sensors, sonic or ultrasonic monitoring might provide valuable information about the condition or alteration of a structure. Sensors such as geophones, recording ambient noise in the sonic and subsonic frequency range can provide information beyond modal analysis by using interferometric methods. Wave velocities determined by this method are related to the elastic properties and stiffness of material and structure and can be converted into damage indicators. Embedded active ultrasonic transducer networks can provide more detailed insight about deterioration or damages again, using interferometric technologies. This approach is extremely sensible, detecting relative change in velocity on down to 10-5. These methods, including benefits and remaining challenges, are demonstrated using data from a test structure at BAM’s test site demonstrating the case of prestress loss, and data from an actual bridge still under traffic. T2 - International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR 2022) CY - Cape Town, South Africa DA - 03.10.2022 KW - Monitoring KW - Ultrasonic KW - Non-destructive testing KW - Coda wave KW - Bridge PY - 2022 AN - OPUS4-56000 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Azari, H. A1 - Shams, S. A1 - Köpp, Christian A1 - Timofeev, Juri A1 - Niederleithinger, Ernst T1 - Development of reference specimens for nondestructive evaluation of concrete bridge decks N2 - Decades of non-destructive evaluation (NDE) for the quality assurance of concrete bridges revealed the necessity of developing procedures for building reference specimens for different defects. External objects have been widely used in specimen construction to represent defects. However, embedded materials can alter the actual defect characteristics, interrupting the NDE responses. This study proposes new approaches to fabricating reference specimens for reinforced concrete that feature substantial defects, including cracks, delamination, honeycombing and rebar corrosion, without external objects. As a result, realistic responses can be acquired to identify promising NDE methods for characterising actual deteriorations. The procedures were produced with the intent of being reproducible in any laboratory. Destructive and non-destructive testing methods were performed to verify the effectiveness of the processes in creating defects. This study provides research laboratories with techniques for fabricating reference specimens for characterising defects and assessing the performance of NDE technologies. KW - Concrete structures KW - Reference KW - Specimen KW - Non-destructive testing KW - Laboratory tests PY - 2023 DO - https://doi.org/10.1680/jfoen.21.00030 SN - 2043-9911 SP - 1 EP - 12 PB - ICE Publishing AN - OPUS4-56957 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pelkner, Matthias T1 - Process monitoring in metal AM@BAM, the project ProMoAM N2 - In this presentation we give an overview of activities regarding non-destructive testing of AM components during the manufacturing process. For this purpose, we installed different NDT methods inside the AM systems. The results obtained during the manufacturing process are presented and discussed. T2 - 74th IIW Annual Assembly and International Conference CY - Online meeting DA - 07.07.2021 KW - Non-destructive testing KW - Additive manufacturing KW - Online monitoring PY - 2021 AN - OPUS4-53186 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Casperson, Ralf T1 - AIFRI - Artificial Intelligence for Rail Inspection N2 - Verlegte Eisenbahnschienen werden mit Schienenprüfzügen, die mit zerstörungsfreier Ultraschall- und Wirbelstromprüftechnik ausgerüstet sind, auf Schienenfehler geprüft. Im Rahmen des mFund-geförderten Projektes AIFRI wurden von der TU Berlin KI-Algorithmen entwickelt, die die Prüfer bei der Auswertung der Daten unterstützen. Felddaten von realen Prüffahrten sind für das Training der KI ungeeignet, da es einerseits kaum Defekte in den Schienen gibt, die sich mit Ultraschall detektieren lassen, andererseits bei der Wirbelstromprüfung zahlreiche Oberflächeneffekte unbekannter Ursache angezeigt werden. Die Aufgabe der BAM bestand darin, durch Simulation gelabelte Trainingsdaten für die KI zu generieren. Während die mit simulierten Daten trainierte KI bei der Ultraschallprüfung eine gute Performance aufweist, sofern der Sim2Real-Gap durch Addition realitätsnaher Rauschsignaturen zu den simulierten Trainingsdaten minimiert wird, erwies sich die verwendete KI bei der Wirbelstromprüfung aufgrund zu vieler Falsch-Positives als ungeeignet. Die Ursache liegt vermutlich darin, dass aufgrund der großen Vielfalt von teils unbekannten Oberflächeneffekten nur eine kleine Auswahl simuliert werden konnte und die KI bei untrainierten Signalsignaturen halluziniert. T2 - AI/ML Symposium CY - Berlin, Germany DA - 06.11.2025 KW - Artificial intelligence KW - Non-destructive testing KW - Ultrasonic testing KW - Eddy current testing KW - Simulation KW - Sim2real gap KW - Railway rail inspection PY - 2025 AN - OPUS4-64630 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Soares, A.P. A1 - Baum, D. A1 - Hesse, B. A1 - Kupsch, Andreas A1 - Müller, Bernd R. A1 - Zaslansky, P. T1 - Scattering and phase-contrast X-ray methods reveal damage to glass fibers in endodontic posts following dental bur trimming N2 - Objectives. There is concern that the integrity of fiberglass dental posts may be affected by chairside trimming during treatment. We hypothesize that hard X-ray methods of phase contrast-enhanced micro-CT (PCE-CT) and synchrotron based X-ray refraction (SXRR) can reliably identify and help characterize the extent of damage. Methods. Fiberglass posts were imaged both as manufactured and following trimming with a diamond bur. Each of the posts was imaged by SXRR and by PCE-CT. Datasets from PCE-CT were used to visualize and quantify 2D and 3D morphological characteristics of intact and of damage-affected regions caused by trimming. Results. The SXRR images revealed fiber inhomogeneities from manufacturing with a significant increase in internal surfaces in sample regions corresponding to damage from trimming. PCE-CT volumes unveiled the micromorphology of single fibers in the posts and some damage in the trimmed area (e.g. fractures, splinters and cracks). Area, perimeter, circularity, roundness, volume and thickness of the glass fibers in the trimmed area were statistically different from the control (p < 0.01). Significance. The integrity of single fibers in the post is critical for bending resistance and for long-term adhesion to the cement in the root canals. Damage to the fibers causes substantial structural weakening across the post diameter. Glass fragments produced due to contact with the dental bur may separate from the post and may significantly reduce bond capacity. The above mentioned synchrotron-based imaging techniques can further facilitate assessment of the structural integrity and the appearance of defects in posts (e.g. after mechanical load). KW - Fiberglass composite KW - Fiber reinforced dental post KW - X-ray refraction KW - Phase contrast-enhanced micro-CT KW - Non-destructive testing PY - 2021 DO - https://doi.org/10.1016/j.dental.2020.10.018 SN - 0109-5641 VL - 37 IS - 2 SP - 201 EP - 211 PB - Elsevier Inc. AN - OPUS4-52071 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Solodov, Dmitry T1 - Exploring the Potential of Plasma Micro-Hollow Cathode Transducers for Air-Coupled Ultrasonic Non-Destructive Testing N2 - Plasma micro-hollow cathode (MHC) transducers offer a novel and promising approach for air-coupled non-destructive testing (NDT), with the distinct capability of generating ultrasonic waves across a broad frequency spectrum. Utilizing ionized gas as the wave-emitting medium, these transducers operate without requiring any physical contact or coupling medium, making them especially attractive for testing delicate or complex surfaces. Their compact design and plasma-driven mechanism allow for flexible deployment and potential miniaturization in various testing environments. This preliminary study investigates the fundamental behavior and performance of MHC plasma transducers in the context of ultrasound-based NDT. A series of experiments were conducted using laser Doppler vibrometry and optical microphone techniques to evaluate the transducers’ ability to generate, propagate, and detect acoustic waves in different materials and geometries, including PMMA, CFRP composites, and 3D-printed PLA structures with artificial defects such as flat-bottom holes and cracks. Results reveal the ability of MHC transducers to emit high-frequency, broadband ultrasonic waves in air, suitable for detecting subsurface anomalies. Although still in the early stages of development, MHC plasma transducers show potential for advancing air-coupled ultrasonic NDT. Future work will focus on optimizing transducer geometry and operating parameters to increase efficiency and signal-to-noise ratio. While conventional linear excitation remains the primary focus, this study also briefly explores the possibility of combining MHC transducers with nonlinear resonance-based methods, such as Local Defect Resonance (LDR), to improve defect sensitivity. Although the integration of MHCs with nonlinear techniques is still a challenging prospect, there is potential for enhanced defect detection, particularly for small or weakly bonded flaws. These methods could offer higher contrast and more precise localization of defects under resonance conditions. However, the implementation of such nonlinear methods would require further research and development. This study provides a foundation for exploring the broader capabilities of plasma-based ultrasound sources in material characterization and structural health monitoring, especially in lightweight, composite, or additively manufactured materials. T2 - ICU2025 - International Congress on Ultrasonics 2025 CY - Paderborn, Germany DA - 21.09.2025 KW - Air-coupled Ultrasound KW - Non-destructive testing KW - Microhollow cathod PY - 2025 AN - OPUS4-64735 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hilger, A. A1 - Kardjilov, N. A1 - Lange, A. A1 - Kupsch, Andreas A1 - Hentschel, M. P. A1 - Manke, I. T1 - Neutron darkfield imaging of fiber composites N2 - While X-ray based darkfield imaging with grating interferometers is already widely used, darkfield imaging with neutrons has still a relatively small user community focused mostly on magnetic materials. Here, we demonstrate the application of neutron darkfield imaging byTalbot-Lau type grating interferometry to fiber reinforced plastics. Common carbon and glass fiber composites have been investigated including characteristic damage structures. The darkfield images show a strong signal response caused by fiber delamination, suitable fiber direction, particles, pores and cracks. The basic principles of neutron darkfield imaging applied to fiber composites are highlighted. KW - Neutron radiography KW - Darkfield imaging KW - Talbot-Lau interferometer KW - Fiber composites KW - Non-destructive testing PY - 2021 DO - https://doi.org/10.1515/mt-2020-0103 SN - 2195-8572 SN - 0025-5300 VL - 63 IS - 7 SP - 623 EP - 629 PB - De Gruyter CY - Berlin AN - OPUS4-53077 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Sobczak, Michał T1 - Badania nieniszczące materiałów z wykorzystaniem termografii laserowej z liniowym źródłem ciepła N2 - Laserowa termografia z liniowym źródłem ciepła to technika o dużym potencjale w diagnostyce materiałów konstrukcyjnych, zarówno kompozytowych, jak i metalicznych. W przeciwieństwie do metod impulsowych, skupiona linia lasera pozwala na kierunkowe wzbudzenie cieplne i precyzyjne odwzorowanie rozkładu temperatury. Przesuwanie linii względem badanej powierzchni umożliwia inspekcję dużych obszarów z wysoką rozdzielczością przestrzenną, co sprzyja wykrywaniu defektów prostopadłych do kierunku propagacji ciepła. Przedmiotem badań jest analiza odpowiedzi termicznej próbki zawierającej dwa typy nieciągłości: otwór płaskodenny (FBH) oraz szczelinę powierzchniową. Symulacje wykonano w programie Marc Mentat, z uwzględnieniem ruchu źródła ciepła i rzeczywistych parametrów materiałowych. Rozkłady temperatury analizowano dwiema metodami: rekonstrukcją pełnego termogramu oraz filtracją gradientową sumowaną w czasie (TSGF). Pierwsza z nich pozwala uzyskać obraz powierzchni próbki tak, jakby została ogrzana jednocześnie, druga wzmacnia kontrast krawędzi szczelin w kierunku prostopadłym do ruchu lasera. Omówiono także wpływ prędkości przesuwu linii lasera na skuteczność detekcji, jako parametru wpływającego na czas wzbudzenia i wrażliwość pomiaru. Dodatkowo przedstawiono wyniki pomiarów eksperymentalnych, które potwierdzają możliwość wykrywania defektów z wykorzystaniem tej metody. Uzyskane odpowiedzi cieplne stanowią uzupełnienie analizy numerycznej i potwierdzają skuteczność metody w warunkach rzeczywistych. N2 - Laser line thermography is a promising technique for the non-destructive evaluation of structural materials, including both composites and metals. Unlike conventional flash methods, a focused laser line enables directional thermal excitation and precise control over surface temperature distribution. Moving the laser line relative to the inspected surface allows testing of large areas with high spatial resolution and supports the detection of defects oriented perpendicular to the heat propagation direction. The study focuses on the thermal response of a sample containing two types of discontinuities: a flat-bottom hole (FBH), representing thickness variation or delamination, and a surface-breaking notch simulating a crack. Numerical simulations were performed in Marc Mentat, using realistic material properties and modeling the motion of the heat source. Temperature distributions were analyzed using two methods: full thermogram reconstruction and Time-Summed Gradient Filtering (TSGF). The first method reconstructs the thermal image of the entire surface as if heated simultaneously, while the second enhances contrast along temperature gradient edges perpendicular to the laser movement. The influence of laser scanning speed on temperature distribution and defect visibility is also discussed. Additionally, experimental results on a sample with an FBH confirm the method’s capability for detecting material discontinuities. The findings support the practical applicability of laser line thermography and complement the numerical analysis. T2 - 52nd Polish National Conference on Non-Destructive Testing (KKBN) CY - Wisla, Poland DA - 21.10.2025 KW - Non-destructive testing KW - Laser thermography KW - Laser line KW - Numerical simulations PY - 2025 AN - OPUS4-64484 LA - pol AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zeipert, H. A1 - Nellius, T. A1 - Schönlau, N. A1 - Wippermann, M. A1 - Claes, L. A1 - Henning, B. A1 - Nicolai, Marcel A1 - Prager, J. T1 - C6-a3 - Monitoring the curing process of adhesive bonds using selective excitation of guided ultrasonic waves N2 - A measurement setup for the selective excitation of guided ultrasonic waves in adhesively bonded plates is introduced. Changes of the dispersive behaviour of the guided waves during the curing process is known to be accompanied by a change in the propagating waves group velocities. The proposed measurement setup is used to monitor that change during the curing process of an aluminium-epoxy-polycarbonate bond. T2 - 2025 ICU PADERBORN - 9th International Congress on Ultrasonics CY - Paderborn, Germany DA - 21.09.2025 KW - Ultrasonic guided waves KW - Selective excitation KW - Non-destructive testing KW - Adhesive bonding KW - Condition monitoring PY - 2025 DO - https://doi.org/10.5162/Ultrasonic2025/C6-a3 SP - 207 EP - 210 PB - AMA Service GmbH AN - OPUS4-65357 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - A unique authenticator for additively manufactured parts derived from their microstructure N2 - In the field of additive manufacturing, the ability to uniquely identify and authenticate parts is crucial for certification, logistics, and anti-counterfeiting efforts. This study introduces a novel methodology that leverages the intrinsic microstructural features of additively manufactured components for their identification, authentication, and traceability. Unlike traditional tagging methods, such as embedding QR codes on the surface [1] or within the volume of parts, this approach requires no alteration to the printing process, as it utilizes naturally occurring microstructural characteristics. The proposed workflow [2] involves the analysis of 3D micro-computed tomography data to identify specific voids that meet predefined identification criteria. This method is demonstrated on a batch of 20 parts manufactured with identical process parameters, proving capable of achieving unambiguous identification and authentication. By establishing a tamper-proof link between the physical part and its digital counterpart, this methodology effectively bridges the physical and digital realms. This not only enhances the traceability of additively manufactured parts but also provides a robust tool for integrating digital materials, parts databases, and product passports with their physical counterparts. T2 - Artificial Intelligence in MSE CY - Bochum, Germany DA - 18.11.2025 KW - Authentication KW - Additive Manufacturing KW - Non-destructive testing PY - 2025 AN - OPUS4-65204 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nicolicea, Alberto T1 - Flexible AMR sensors for novel non destructive testing capabilities N2 - Reshapeable magnetic field sensors fabricated on flexible substrates by thin-film deposition or printing have recently emerged with promising applications in different field. In this study, flexible anisotropic magneto-resistive (AMR) sensors were used for the scanning of a curved and flat sample with reference defects, to prove the capability of this method for curved surface scanning, and to benchmark the performance when compared to a more stand-ard method using rigid giant magneto-resistive (GMR) sensors. Defects with depths ranging from 110 μm up to 2240 μm were detected with a signal-to-noise ratio (SNR) of 2.7 up to 27.9 employing flexible AMR sensors. T2 - XMR-Symposium CY - Wetzlar, Germany DA - 12.03.2025 KW - Non-destructive testing KW - Flexible sensor KW - Magnetoresistance PY - 2025 AN - OPUS4-65033 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Nicolicea, Alberto T1 - Flexible magnetoresistive sensors for novel applications N2 - Flexible electronics is an emerging field that has been gaining a lot of attention in recent years, with the appearance of flexible solar panels, screens and other such novel devices. Recent developments in this area have lead to the appearance of flexible magnetic field sensors which are produced by thin-film deposition on flexible substrates. These devices show promising capabilities for several applications such spatial navigation, micro-fluidic particle detection, biomedical applications and intelligent textiles [1]. One possible field of interest is the application of these devices for electromagnetic (EM) non-destructive testing (NDT), since it would enable in-contact scanning of surfaces with arbitrary shapes. Flexible anisotropic magnetoresistive (AMR) sensors mounted on a rotative mechanical holder were used to scan a semi-circular ferromagnetic sample with 3 reference defects via magnetic ux leakage (MFL) testing, thus demonstrating the applicability of this method for the scanning of curved surfaces. T2 - SMSI 2025 CY - Nuremberg, Germany DA - 06.05.2025 KW - Non-destructive testing KW - Flexible sensor KW - Magnetoresistance PY - 2025 AN - OPUS4-65032 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gaal, Mate A1 - Álvarez-Arenas, Tomás Gómez T1 - Guest Editorial: Special Section on Air-Coupled Ultrasound N2 - Air-coupled ultrasound is a challenging field dominated by the drastic impedance mismatch between air and all condensed matter, the low ultrasound velocity in the air, and the rapidly increasing attenuation with frequency. The seven articles included in this special section showcase the diversity of current research on air-coupled ultrasound. All contributions in this special section are application-oriented, demonstrating the readiness of air-coupled ultrasound technologies to address real-world challenges. Whether it’s ensuring food safety, supporting heritage conservation, optimizing industrial inspection, or enabling in-field biological measurements, the practical relevance of these studies makes this section particularly valuable for both researchers and industry professionals. KW - Air-coupled ultrasound KW - Transducers KW - Non-destructive testing PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-655041 DO - https://doi.org/10.1109/OJUFFC.2026.3656857 SN - 2694-0884 VL - 6 SP - 1 EP - 2 PB - Institute of Electrical and Electronics Engineers (IEEE) AN - OPUS4-65504 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dayani, Shahabeddin A1 - Markötter, Henning A1 - Schmidt, Anita A1 - Widjaja, Martinus Putra A1 - Bruno, Giovanni T1 - Multi-level X-ray computed tomography (XCT) investigations of commercial lithium-ion batteries from cell to particle level N2 - Adopting X-ray computed tomography (XCT) for ex-situ characterization of battery materials has gained interest in the past decade. The main goal of this paper is to demonstrate the effectiveness of several X-ray computer tomography techniques to study commercial batteries. General guidelines are provided to select the most suitable imaging equipment and parameters for investigations of lithium-ion batteries, spanning the length scales from cell to electrode, down to particle level. Relevantly, such parameters would also be suitable for operando experiments. Safety mechanisms and manufacturing inconsistencies at cell level as well as defects and inhomogeneity in cathode and anode is illustrated and quantified. Furthermore, relation of beam energy and sample-detector-distance on contrast retrieved from attenuation and phase shift is inspected using Synchrotron XCT. KW - Non-destructive testing KW - X-ray computed tomography KW - Synchrotron X-ray computed tomography KW - Lithium-ion battery PY - 2023 DO - https://doi.org/10.1016/j.est.2023.107453 SN - 2352-152X VL - 66 SP - 107453 PB - Elsevier Ltd. AN - OPUS4-57512 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wieder, Frank T1 - X-ray refraction radiography applied to Dental Fibre Posts N2 - Fibre-Matrix-Debonding in glass fibre reinforced dental posts can play an important role for their mechanical performance and long term stability… We show that synchrotron X-ray refraction radiography (SXRR) allows analysis of large samples (up to several millimetres) without compromising the detectability of sub micrometer defects. T2 - HZB User Meeting 2021 CY - Online meeting DA - 09.12.2021 KW - X-ray refraction KW - Fiber reinforced dental post KW - Fiberglass composite KW - Non-destructive testing PY - 2021 AN - OPUS4-54092 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hirsch, Philipp Daniel A1 - Kunji Purayil, Sruthi Krishna A1 - Lecompagnon, Julien A1 - Pech May, Nelson Wilbur A1 - Ziegler, Mathias ED - Maldague, X. T1 - Robotic-Assisted 3D Scanning and Laser Thermography for Crack Inspection on Complex Components N2 - The integration of automation and robotics into non-destructive testing (NDT) marks a significant advancement in evaluating complex components. This paper introduces a novel approach using robotic-assisted laser thermography combined with automated 3D scanning to detect and analyze cracks in complex structures. The system uses an integrated line scanner with a robotic arm to capture high-resolution data, creating detailed 3D models for adaptive path planning and precise alignment correction. Laser thermography, based on localized heating and the "flying spot" approach, detects surfacenear cracks with high precision. Crack detection is achieved using the Canny algorithm optional on Fourier-transformed thermograms, offering robust results with minimal computation. This study highlights the potential of robotic-assisted 3D scanning and laser thermography as efficient and precise methods for crack inspection, advancing NDT technologies and ensuring the structural integrity of modern components. T2 - 17th International Conference on Quantitative InfraRed Thermography 2024 CY - Zagreb, Croatia DA - 01.07.2024 KW - Thermography KW - Non-destructive testing KW - Laser line KW - Robotic arm KW - Defect identification KW - Crack detection PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-653809 DO - https://doi.org/10.21611/qirt-2024-078 SP - 1 EP - 8 PB - QIRT Council AN - OPUS4-65380 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kunji Purayil, Sruthi Krishna A1 - Hirsch, Philipp Daniel A1 - Lecompagnon, Julien A1 - Ziegler, Mathias ED - Ferrarini, Giovanni ED - López, Fernando ED - Spaeth, Peter T1 - Multispectral fusion-based crack detection using automated laser thermography inspection N2 - Crack detection of complex components is critical for maintaining the integrity and safety of structures across industries such as energy production and aerospace. The integration of multispectral imaging and automatic robot-based non-destructive testing (NDT) marks a significant advancement in the inspection of complex geometries. Multispectral imaging leverages the utilization of image data from different wavelength ranges for enhanced feature extraction and analysis. This paper proposes a novel image fusion model by combining thermal and visual images for the detection of surface and sub-surface cracks of turbine blades in energy production. Our study uses 3D scanning of components using a robot-assisted flying laser line, which measures high-resolution thermal data and RGB images using visual cameras simultaneously. Laser thermography induces a localized heating on the sample, creating a thermal response that highlights cracks and defects that are often undetectable using conventional imaging techniques. Multispectral image fusion models are developed based on an unsupervised generative adversarial network (GAN) for precise crack detection. The model validation is done using experimental data and it demonstrated high crack detection accuracy compared to conventional single-band imaging methods. This research highlights the new potential for advancing NDT technologies by combining thermal inspection techniques with optical imaging to develop a multispectral inspection approach. T2 - Thermosense: Thermal Infrared Applications XLVII CY - Orlando, Florida, United States DA - 13.04.2025 KW - Infrared imaging KW - Laser KW - Multispectral imaging KW - NDE 4.0 KW - Non-destructive testing PY - 2025 DO - https://doi.org/10.1117/12.3052496 SP - 1 EP - 11 PB - SPIE AN - OPUS4-63253 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kunji Purayil, Sruthi Krishna T1 - Preserving History: Application of Active Thermography for Investigating the Bücker Bü 181 Aircraft N2 - Infrared thermography is a widely recognized non-destructive testing (NDT) method used in material research and defect detection across various industrial applications. Moreover, thermography plays a crucial role in preserving cultural heritage, including historical paintings and buildings. This study focuses on the application of thermography in inspecting the historic Bücker Bü 181 aircraft, which was used in Germany during World War II. Over time, the original appearance of aircraft has often been altered as part of preservation efforts, either before or during their time in museums, leading to deviations from their historically original state. Additionally, the operational history of such objects is frequently undocumented or entirely lost, making it difficult to understand the presence of artifacts and historically significant data. These factors present major challenges in cultural heritage preservation, and destructive methods cannot be used to investigate such invaluable objects. Therefore, thermography is implemented as a non-destructive and contactless examination method. Active flash thermography combined with phase analysis is a powerful tool for evaluating multilayer systems. In this study, multiple layers of old paint on the object posed a challenge in assessing defect conditions and retrieving other critical information beneath the surface coatings. Nevertheless, pulse thermography not only demonstrated its capability to identify defects and markings in multilayered coatings but also provided insights into the internal structure and subsections of the investigated aircraft. T2 - DGZFP Jahrestagung 2025 CY - Berlin, Germany DA - 26.05.2025 KW - Non-destructive testing KW - Infrared thermography KW - Multilayer coatings KW - Cultural heritage KW - Defect detection PY - 2025 AN - OPUS4-63255 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kunji Purayil, Sruthi Krishna T1 - Multispectral fusion-based crack detection using automated laser thermography inspection N2 - Crack detection of complex components is critical for maintaining the integrity and safety of structures across industries such as energy production and aerospace. The integration of multispectral imaging and automatic robot-based non-destructive testing (NDT) marks a significant advancement in the inspection of complex geometries. Multispectral imaging leverages the utilization of image data from different wavelength ranges for enhanced feature extraction and analysis. This paper proposes a novel image fusion model by combining thermal and visual images for the detection of surface and sub-surface cracks of turbine blades in energy production. Our study uses 3D scanning of components using a robot-assisted flying laser line, which measures high-resolution thermal data and RGB images using visual cameras simultaneously. Laser thermography induces a localized heating on the sample, creating a thermal response that highlights cracks and defects that are often undetectable using conventional imaging techniques. Multispectral image fusion models are developed based on an unsupervised generative adversarial network (GAN) for precise crack detection. The model validation is done using experimental data, and it demonstrated high crack detection accuracy compared to conventional single-band imaging methods. This research highlights the new potential for advancing NDT technologies by combining thermal inspection techniques with optical imaging to develop a multispectral inspection approach. T2 - SPIE Defense+Commercial Sensing- Thermosense: Thermal Infrared Applications XLVII CY - Orlando, FL, USA DA - 13.04.2025 KW - Non-destructive testing KW - Infrared imaging KW - NDE 4.0 KW - Multispectral imaging KW - Laser PY - 2025 AN - OPUS4-63050 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Dayani, Shahabeddin T1 - Quantification of Deep Discharge Mechanism in a Li-Ion Battery by operando X-ray Computed Tomography N2 - Lithium-ion batteries connected in series are prone to an electrical abuse called over discharge. We present a comprehensive investigation of the over discharge abuse mechanism in lithium-ion batteries using operando non-destructive imaging. The study focuses on understanding the behavior of copper dissolution and deposition during over discharge, which can lead to irreversible capacity loss and internal short circuits. By utilizing synchrotron X-ray computed tomography (SXCT), the concentration of dissolved and deposited copper per surface area is quantified as a function of depth of discharge (DoD). T2 - HZB user meeting CY - Berlin, Germany DA - 22.06.2023 KW - Non-destructive testing PY - 2023 AN - OPUS4-57793 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - A unique authenticator for additively manufactured parts derived from their microstructure N2 - The international research community is currently devoting extensive resources to the development of digital material data spaces and the associated digital twins and product passports of materials and components. A common weak link in these projects to date has been the connection between physical components / samples and their digital data and documents. This is where the concept of the unique identification comes in. Components produced using additive manufacturing can be marked for unique identification and secure authentication [1,2]. Serial numbers and machine-readable codes can be used to identify the component, and link digital product-related data (i.e., a digital product passport) to the actual components. The most prevailing solution consists of local process manipulation, such as printing a quick response (QR) code [3] or a set of blind holes on the surface or the internal cavity of hollow components. However, local manipulation of components may alter the properties, and external tagging features can be altered or even removed by post-processing treatments. This work provides a new methodology for identification, authentication, and traceability of additively manufactured (AM) components using microstructural features that are unique to each part. X-ray computed tomography (XCT) was employed to image the microstructural features of a batch of AlSi10Mg parts. Based on size and geometry, the most prominent features were selected to create a unique digital authenticator. We implemented a framework in Python using open-access modules that can successfully create a digital object authenticator using the segmented microstructure information from XCT. We show that this method allows to authenticate individual parts from the build job based on its microstructural fingerprint. This is our contribution to enhancing the security and product protection of additively manufactured components. T2 - FEMS EUROMAT CY - Granada, Spain DA - 15.09.2025 KW - Authentication KW - Fingerprint KW - Non-destructive testing PY - 2025 AN - OPUS4-65202 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Waske, Anja T1 - A unique authenticator for additively manufactured parts derived from their microstructure N2 - Components produced using additive manufacturing can be marked for unique identification and secure authentication [1,2]. Serial numbers and machine-readable codes can be used to identify the component, and link digital product-related data (i.e., a digital product passport) to the actual components. The most prevailing solution consists of local process manipulation, such as printing a quick response (QR) code [3] or a set of blind holes on the surface of the internal cavity of hollow components. However, local manipulation of components may alter the properties, and external tagging features can be altered or even removed by post-processing treatments. This work therefore aims to provide a new methodology for identification, authentication, and traceability of additively manufactured (AM) components using microstructural features that are unique to each part. X-ray computed tomography (XCT) was employed to image the microstructural features of AlSi10Mg parts. Based on size and geometry, the most prominent features were selected to create a unique digital authenticator. We implemented a framework in Python using open-access modules that can successfully create a digital object authenticator using the segmented microstructure information from XCT. The authenticator is stored as a QR code, along with the 3D information of the selected features. T2 - MRS Spring Meeting Seattle CY - Seattle, WA, USA DA - 07.04.2025 KW - Additive Manufacturing KW - Fingerprint KW - Non-destructive testing PY - 2025 AN - OPUS4-65199 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph A1 - Schönsee, Eric A1 - Jeyifous, Olubunmi Anthony A1 - Mezhov, Alexander A1 - Hüsken, Götz T1 - Introduction of a monitoring system for Bingham fluids in additive manufacturing with concrete N2 - Freeform additive manufacturing of concrete structures is a rising technology in civil engineering with several fascinating advantages. Nonetheless, to ensure reliability and structural integrity, standards and quality control are required in the future to bring this technology into the market. As the concrete is manufactured continuously, continuous quality control of the printing process is also required, i.e. comprehensive process monitoring. At BAM, a test rig will be installed, enabling the printing of concrete structures with a maximum size of 2 m x 1 m x 1 m (l x w x h). Here, process monitoring is the focus of the test rig. In this study, we show the results of the first pump tests, including the measurement of several parameters such as temperature and pressure along the supply system, i.e. from the concrete pump to the printer head. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Additive manufacturing of concrete KW - Process monitoring KW - Non-destructive testing KW - Bingham fluid PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-556367 SP - 1 EP - 12 AN - OPUS4-55636 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Strangfeld, Christoph T1 - Introduction of a monitoring system for Bingham fluids in additive manufacturing with concrete N2 - Freeform additive manufacturing of concrete structures is a rising technology in civil engineering with several fascinating advantages. Nonetheless, to ensure reliability and structural integrity, standards and quality control are required in the future to bring this technology into the market. As the concrete is manufactured continuously, continuous quality control of the printing process is also required, i.e. comprehensive process monitoring. At BAM, a test rig will be installed, enabling the printing of concrete structures with a maximum size of 2 m x 1 m x 1 m (l x w x h). Here, process monitoring is the focus of the test rig. In this study, we show the results of the first pump tests, including the measurement of several parameters such as temperature and pressure along the supply system, i.e. from the concrete pump to the printer head. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Additive manufacturing of concrete KW - Process monitoring KW - Non-destructive testing KW - Bingham fluid PY - 2022 AN - OPUS4-55637 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Küttenbaum, S. A1 - Braml, T. A1 - Kainz, C. A1 - Maack, Stefan A1 - Taffe, A. T1 - Guidance on inspection-supported reliability assessment of existing bridges in Germany N2 - This contribution is intended to disseminate the contents of a national recommendation for Action draft for the inspection-based reliability analysis of existing bridges. The focus is on the utilization of non-destructive testing methods for verifications in both the ultimate and the serviceability Limit states. First, the contents of the developed recommendation for action are outlined. The Guideline covers the process from the purposeful definition of inspection strategies via the quality assessment of measured information to the partial factor-based assessment under consideration of qualityevaluated on-site inspection results. Secondly, the concept of the drafted recommendation for action is demonstrated using a prestressed concrete bridge as a case study. T2 - IABSE Symposium Tokyo 2025 CY - Tokyo, Nippon DA - 18.05.2025 KW - Life management KW - Brücken KW - Non-destructive testing KW - Civil engineering KW - State-of-the-art PY - 2025 DO - https://doi.org/10.1080/10168664.2024.2363597 VL - 34 IS - 3 SP - 1 EP - 8 AN - OPUS4-65630 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -