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 - Bernegger, Raphael A1 - Maierhofer, Christiane A1 - Altenburg, Simon T1 - Quantification of delaminations in semitransparent solids using pulsed thermography and mathematical 1D models N2 - Material defects in fiber reinforced polymers such as delaminations can rapidly degrade the material properties or can lead to the failure of a component. Pulse thermography (PT) has proven to be a valuable tool to identify and quantify such defects in opaque materials. However, quantification of delaminations within semitransparent materials is extremely challenging. We present an approach to quantify delaminations within materials being semitransparent within the wavelength ranges of the optical excitation sources as well as of the infrared (IR) camera. PT experimental data of a glass fiber reinforced polymer with a real delamination within the material were reconstructed by one dimensional (1D) mathematical models. These models describe the heat diffusion within the material and consider semitransparency to the excitation source as well to the IR camera, thermal losses at the samples surfaces and a thermal contact resistance between the two layers describing the delamination. By fitting the models to the PT data, we were able to determine the depth of the delamination very accurately. Additionally, we analyzed synthetic PT data from a 2D simulation with our 1D-models to show how the thermal contact resistance is influenced by lateral heat flow within the material. KW - Pulsed thermography KW - Quantification KW - Numerical simulation KW - Analytical model KW - Semitransparent KW - GFRP KW - Delamination PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-505766 DO - https://doi.org/10.1007/s10765-020-02642-7 VL - 41 IS - 5 SP - Article number: 67 PB - Springer AN - OPUS4-50576 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Krankenhagen, Rainer A1 - Doroshtnasir, Manoucher A1 - Maierhofer, Christiane A1 - Brackrock, Daniel A1 - Brekow, Gerhard T1 - Charakterisierung einer durch Überlast geschädigten GFK-Platte mit Thermografie und Ultraschall N2 - Eine GFK-Platte mit eingefräster Nut wurde in einem Zugversuch mit ca. 90 kN belastet, was zu einer sichtbaren Veränderung an den Seitenflächen führte. Anschließend wurde die Platte mit Ultraschall und Thermografie auf innere Schädigungen untersucht. Beide Verfahren konnten räumlich ausgedehnte Bereiche mit zahlreichen Anzeigen nachweisen, jedoch keine geschlossene Fläche. Mit UT wurden außerdem porenreiche oberflächennahe Schichten in dem Material detektiert. Diese Poren verringerten die Nachweisempfindlichkeit beider Messverfahren. T2 - DGZfP-Jahrestagung 2013 CY - Dresden, Germany DA - 06.05.2013 KW - Blitzthermografie KW - Matrixarray KW - GFK KW - Delamination KW - Überlast PY - 2013 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-285563 SN - 978-3-940283-49-8 IS - Mi.3.A.1 SP - 1 EP - 8 PB - Deutsche Gesellschaft für zerstörungsfreie Prüfung e.V. (DGZfP) AN - OPUS4-28556 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sobczak, M. A1 - Lecompagnon, Julien A1 - Hirsch, Philipp Daniel A1 - Pieczonka, Ł. A1 - Ziegler, Mathias T1 - Impact damage characterization on CFRP parts using laser line scanning active thermography N2 - This study presents a dual-path data processing framework for the detection and characterization of barely visible impact damage (BVID) in carbon-fiber-reinforced polymer (CFRP) structures using laser line thermography (LLT). A robotic LLT system was used to scan impacted CFRP specimens, and the resulting thermal sequences were analyzed using two complementary methods: full thermogram reconstruction followed by Pulse Phase Thermography (PPT) to detect subsurface delaminations, and Time-Summed Gradient Filtering (TSGF) to enhance surface-breaking cracks. Both processing paths produced interpretable results that were fused into a unified combined image and overlay mask, enabling simultaneous visualization of different defect types from a single scan. Quantitative analysis was performed on the binary masks to extract defect dimensions and Signal-to-noise ratio (SNR) values. The results demonstrated that delaminations and multiple cracks could be accurately detected and spatially distinguished, with good agreement to reference methods such as flash thermography and vibrothermography. This work highlights the potential of LLT as a versatile and scalable inspection technique, where multimodal defect detection and segmentation can be achieved through targeted processing and data fusion strategies. KW - Active thermography KW - CFRP KW - Laser line scanning KW - Delamination KW - Cracks KW - BVID KW - NDT PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-654097 DO - https://doi.org/10.1016/j.compositesb.2026.113425 SN - 1359-8368 VL - 313 SP - 1 EP - 9 PB - Elsevier Ltd. AN - OPUS4-65409 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -