TY - CONF A1 - Niemz, P. A1 - Baensch, Franziska A1 - Brunner, A. J. A1 - Gaff, M. T1 - Acoustic Emission Analysis and Synchrotron- Based Microtomography on Glued Shear Strength Samples from Spruce Solid Wood N2 - For a better understanding of the damage of glued wood tensile tests on miniature specimens made of glued spruce wood with acoustic emission and in-situ synchrotron-based X-ray computer microtomography has been monitored. As adhesive, urea-formaldehyde resin was used. For comparison purposes, tensile tests were carried out on solid wood and bonded miniature tensile shear samples with acoustic emission. The acoustic emission signals of all experiments were with classified pattern recognition. This resulted in two classes of signals for each two frequency peaks. In one class was the low-frequency, in the other the higher frequency peak of higher intensity, but this essentially independent from the structure (solid wood or plywood) and the size scale of the test specimens. The influence of the adhesive layers was determined on plywood test specimens in laboratory scale and on miniature test specimens with an adhesive layer and selected fiber orientations examined. This gave evidence that the sound emission signals from the failure of the adhesive layer presumably of the class with low frequency signals peak in the range of services can be assigned. T2 - 21st International Nondestructive Testing and Evaluation of Wood Symposium CY - Freiburg, Germany DA - 24.09.2019 KW - Bondline KW - Insitu test KW - Acoustic emission KW - Sychrotron tomography PY - 2019 SP - 168 EP - 175 AN - OPUS4-49558 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Niemz, P. A1 - Baensch, Franziska A1 - Brunner, A. J. ED - Pavalache-Ilie, M. ED - Curtu, A. L. T1 - Acoustic Emission Analysis And Synchrotron-based Microtomography of glued shear strength samples from spruce wood N2 - To better understanding the failure of adhesive joints tensile tests were carried out on miniature test specimens from Norway spruce in the synchrotron. Urea-formaldehyde resin was used as adhesive. e. For comparison purposes, tensile tests were carried out on solid wood and on bonded miniature tensile shear samples with acoustic emission. The acoustic emission signals of all the experiments occurred with classified pattern recognition. This resulted in two classes of signals for each two frequency peaks. One class consisted of the low-frequency and the other of the higher-frequency peak of higher intensity, but this was essentially independent from the structure (solid wood or plywood) and size scale of the test specimens. The influence of the adhesive layers was determined on wood test specimens on laboratory scale and on miniature test specimens with an adhesive layer and selected fiber orientations. This gave evidence that the sound emission signals from the failure of the adhesive layer presumably of the class with low frequency signals peak in the range of services can be assigned. KW - Wood KW - Bondline KW - In-situ test KW - Acoustic emission KW - Synchrotron tomography PY - 2020 U6 - https://doi.org/10.31926/but.fwiafe.2020.13.62.1.7 VL - 13 IS - 62 Part 1 SP - 81 EP - 88 PB - Transilvania University Press, Brasov, Romania CY - Brasov AN - OPUS4-51010 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Brunner, A. J. A1 - Bohse, Jürgen T1 - Acoustic emission standards and guidelines 2002 - a comparative assessment and perspectives N2 - A comparative analysis of selected standards and guidelines on Acoustic Emission testing published by international and national organisations yields an assessment of the current status of standardisation. Areas where existing documents do not yet exist or appear unsatifactory for some reason are identified and formulated as perspectives for further work. In the future, structural integrity assessment with Acoustic Emission methods is expected to gain in importance. PY - 2002 UR - http://www.ndt.net/article/v07n09/21/21.htm SN - 1435-4934 VL - 7 IS - 9 SP - 1 EP - 10 PB - NDT.net CY - Kirchwald AN - OPUS4-1792 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bohse, Jürgen A1 - Krietsch, Torsten A1 - Chen, J. H. A1 - Brunner, A. J. ED - Williams, J. G. ED - Pavan, A. T1 - Acoustic emission analysis and micro-mechanical interpretation of mode I fracture toughness tests on composite materials N2 - Mode I fracture toughness tests on Double Cantilever Beam specimens from carbon-fibre and glassfibre reinforced polymer-matrix composites were monitored with Acoustic Emission (AE) and loaddisplacement traces and delamination lengths were recorded. AE characterized the kinetics of delamination propagation. The progress of AE activity and AE intensity with load and AE source location plots are used to determine the delamination onset on the microscopic and macroscopic scale. Energy dissipating processes initiated in the damage zone near the delamination tip. Low Interface adhesion results in lower debonding stresses and larger damage zones compared with composites with good adhesion. Time-dependent linear location of AE sources yields the average length of the damage zone and the average speed of delamination propagation. Parameter analysis has been used empirically for identifying AE source mechanisms. A new Classification Software for transient AE waveforms permits identification of the source mechanism of individual AE signals. A micro-mechanical fracture model based on the AE results describes the contributions of microscopic matrix and Interface mechanisms to the interlaminar fracture energy. T2 - 2nd ESIS TC4 Conference on Fracture of Polymers, Composites, and Adhesives CY - Les Diablerets, Switzerland DA - 13.09.1999 KW - Mode I KW - DCB test KW - Acoustic emission analysis KW - Polymer composites KW - Damage zone KW - Micro-mechanisms KW - Interface adhesion KW - Micro-mechanical fracture model KW - Interlaminar fracture energy PY - 2000 SN - 0-08-043710-9 SN - 1566-1369 N1 - Serientitel: ESIS publication – Series title: ESIS publication IS - 27 SP - 15 EP - 26 PB - Elsevier CY - Amsterdam AN - OPUS4-4153 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bohse, Jürgen A1 - Brunner, A.J. A1 - Pöppl, J. A1 - Tscheliesnig, P. T1 - Qualifizierung und Zertifizierung von Personal für die Schallemissionsprüfung (AT) T2 - 19. Kolloquium Schallemission - Statusberichte zur Entwicklung und Anwendung der Schallemissionsanalyse CY - Augsburg, Germany DA - 2013-09-12 KW - Schallemissionsprüfung (AT) KW - Prüfpersonal KW - Ausbildung KW - Zertifizierung (DIN EN ISO 9712) PY - 2013 SN - 978-3-940283-51-1 N1 - Serientitel: DGZfP-Berichtsband – Series title: DGZfP-Berichtsband IS - 142 SP - 1 EP - 5 (Beitrag 21) PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung CY - Berlin AN - OPUS4-28938 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Bohse, Jürgen A1 - Brunner, A.J. ED - S. Sridharan, T1 - Acoustic emission in delamination investigation KW - Acoustic emission KW - Delamination KW - Polymer composites PY - 2008 SN - 978-1-84569-244-5 IS - Part 2 / Chapter 9 SP - 1 EP - 58 PB - Woodhead Publishing Ltd AN - OPUS4-18220 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Baensch, Franziska A1 - Brunner, A. J. ED - Rosemarie, Helmerich ED - Ilki, A. ED - Motavalli, M. T1 - Towards predictor development for assessing structural integrity of components made from wood materials using Acoustic Emission monitoring and signal analysis N2 - Against the background of sustainable resource management and efficiency, wood-based materials are currently experiencing a revival and, among others, plywood, Laminated Veneer Lumber and glued laminated timber are becoming increasingly more important in the building sector. Even though these materials are so-called engineered products, the element wood is naturally grown with intrinsic variability in mechanical properties and requires professional handling on-site. Otherwise, load-bearing structures made of wood materials may entail certain risks. Critical situations can, in principle, be avoided by implementing a structural health monitoring system into components or structures made from wood material. The aim is to indicate accumulation of mechanical damage and to eliminate or at least significantly reduce the risk of unexpected failure. Toward this purpose, the failure behavior of several layered wood materials under quasi-static tension was investigated in laboratory-scale experiments by means of acoustic emission (AE) measurement. Based on spectral analysis and pattern recognition, two classes of AE signals are identified for each investigated lay-up that are characterized by either low or high frequency contents in the respective power spectra. AE activity and intensity of both signal classes are analyzed, striving for predictors appropriate for AE monitoring concepts. T2 - 5th International Conference on Smart Monitoring, Assessment and Rehabilitation of Civil Structures (SMAR 2019) CY - Potsdam, Germany DA - 27.08.2019 KW - Acoustic Emission Monitoring KW - Signal Analysis KW - Structural Integrity KW - Wood Materials PY - 2019 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-491198 SN - 978-3-947971-07-7 SP - Paper Tu.2.D.4, 1 EP - 8 PB - German Society for Non-Destructive Testing (DGZfP e.V.) AN - OPUS4-49119 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -