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Wood Research and Technology

Holzforschung

Cellulose – Hemicelluloses – Lignin – Wood Extractives

Editor-in-Chief: Faix, Oskar

Editorial Board: Daniel, Geoffrey / Militz, Holger / Rosenau, Thomas / Salmen, Lennart / Sixta, Herbert / Vuorinen, Tapani / Argyropoulos, Dimitris S. / Balakshin, Yu / Barnett, J. R. / Burgert, Ingo / Rio, Jose C. / Evans, Robert / Evtuguin, Dmitry V. / Frazier, Charles E. / Fukushima, Kazuhiko / Gindl-Altmutter, Wolfgang / Glasser, W. G. / Holmbom, Bjarne / Isogai, Akira / Kadla, John F. / Koch, Gerald / Lachenal, Dominique / Laine, Christiane / Mansfield, Shawn D. / Morrell, J.J. / Niemz, Peter / Potthast, Antje / Ragauskas, Arthur J. / Ralph, John / Rice, Robert W. / Salin, Jarl-Gunnar / Schmitt, Uwe / Schultz, Tor P. / Sipilä, Jussi / Takano, Toshiyuki / Tamminen, Tarja / Theliander, Hans / Welling, Johannes / Willför, Stefan / Yoshihara, Hiroshi

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Volume 67, Issue 8

Issues

Delamination detection in a 90-year-old glulam block with scanning dry point-contact ultrasound

Jürg Neuenschwander
  • Corresponding author
  • Electronics/Metrology/Reliability Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
  • Email
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Sergio J. Sanabria
  • Electronics/Metrology/Reliability Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
  • Present address: Laboratory for Wood Physics and Non Destructive Testing Methods, Institute for Building Materials, ETH Zurich, Schafmattstrasse 6, CH-8093 Zurich, Switzerland
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Philipp Schuetz
  • Electronics/Metrology/Reliability Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Robert Widmann
  • Structural Engineering Research Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
/ Mareike Vogel
  • Architecture, Wood and Civil Engineering, Berne University of Applied Sciences, Solothurnstrasse 102, CH-2500 Biel 6, Switzerland
  • Other articles by this author:
  • De Gruyter OnlineGoogle Scholar
Published Online: 2013-04-13 | DOI: https://doi.org/10.1515/hf-2012-0202

Abstract

Glued laminated timber (glulam) is known in timber constructions since more than 100 years. Glulam members can delaminate due to aging and excessive changes of temperature and humidity. This results in significantly reduced load bearing capability of the affected structural members. This contribution focuses on the ultrasonic point-contact inspection of gluing plane delamination as a nondestructive method. Ultrasonic measurements on a section of a 90-year-old roofing glulam member are presented. The results are compared with manual detection and evaluation of delamination with a feeler gauge, with X-ray computed tomography analyses, and with numerical simulations. Appropriate data evaluation of the mechanized ultrasonic results allows the determination of material separation that are deeper than 20 mm in the signature of the surface wave and large-scale delamination (>80% of the complete bonding width) in the back-wall echo. Numerical simulations based on the finite-difference time-domain method shed light into the details of the wave propagation and support the experimental findings.

Keywords: bonding quality; delamination; glue line; glued laminated timber; integrity assessment; nondestructive evaluation; point-contact ultrasonics; X-ray computed tomography

References

  • Aicher, S., Dill-Langer, G., Stritzke, C. Qualitätsprüfung von Klebefugen in Brettschichtholz mittels Ultraschall, Jahresbericht MPA, Universität Stuttgart, Germany, 2010.Google Scholar

  • Angst, V., Malo, K.A. (2010) Moisture induced stresses perpendicular to the grain in glulam: review and evaluation of the relative importance of models and parameters. Holzforschung 64:609–617.Web of ScienceGoogle Scholar

  • Blass, H.J., Frese, M. Schadensanalyse von Hallentragwerken aus Holz. Tech. Rep., Karlsruher Institut für Technologie (KIT), Karlsruhe, Germany, 2010.Google Scholar

  • Bucur, V. Delamination in Wood, Wood Products and Wood-Based Composites. Springer, New York, USA, 2011.Google Scholar

  • Casado, M., Acuña, L., Basterra, L.-A., Ramón-Cueto, G., Vecilla, D. (2012) Grading of structural timber of Populus × euramericana clone I-214. Holzforschung 66:633–638.Google Scholar

  • Dietsch, P., Hösl, M. (2010) Mapping of cracks. In: Methods for the Assessment of Timber Structures, COST Action E55. Modelling of the Performance of Timber Structures. Eds. Dietsch, P., Köhler, J. TUM Munich, Germany. pp. 52–54.Google Scholar

  • Dill-Langer, G., Bernauer, W., Aicher, S. (2005) Inspection of glue-lines of glued laminated timber by means of ultrasonic testing. In: Proc. 14th Int. Symp. NDT Wood, Eberswalde, Germany. pp. 49–60.Google Scholar

  • Dimanche, M., Capretti, S., Del Senno, M., Facaoaru, I. (1994) Validation of theoretical approach for the detection of delamination in glued laminated beams. In: 1st Eur. Symp. NDE Wood. University of Forestry and Wood Science, Sopron, Hungary. pp. 250–260.Google Scholar

  • Divos, F. (2011) Delamination evaluation of in-service glulam beams and other structural members via ultrasonics. In: Delamination in Wood, Wood Products and Wood-Based Composites. Ed. Bucur, V. Springer, New York, USA. Chapter 17. pp. 353–364.Google Scholar

  • Drossaert, F.H., Giannopoulos, A. (2007) Complex frequency shifted convolution PML for FDTD modelling of elastic waves. Wave Motion 44:593–604.Web of ScienceCrossrefGoogle Scholar

  • EN 1330-4. (2010) Non-destructive testing—Terminology. Part 4: terms used in ultrasonic testing.Google Scholar

  • Follrich, J., Stöckel, F., Konnerth, J. (2010) Macro- and micromechanical characterization of wood-adhesive bonds exposed to alternating climate conditions. Holzforschung 64:705–711.Web of ScienceGoogle Scholar

  • Garab, J., Toth, A., Szalai, J., Bejo, L., Divos, F. (2010) Evaluating glued laminated beams using a nondestructive testing technique. Trans. Famena 34:33–46.Google Scholar

  • Hansson, M., Larson, H. (2005) Recent failure in glulam structures and their causes. Eng. Fail. Anal. 12:808–818.CrossrefGoogle Scholar

  • Hasenstab, A. (2006) Integritätsprüfung von Holz mit dem zerstörungsfreien Ultraschallechoverfahren, Dissertation (Ph.D. Thesis), Technische Universität Berlin, Germany.Google Scholar

  • Hasenstab, A. (2007) Ultraschall-Echo zur Ortung von Rissen in Brettschichtholz (BSH). Tagungsband DGZfP Jahrestagung, Fürth, Germany.Google Scholar

  • Hörig, H. (1935) Anwendung der Elastizitätstheorie anisotroper Körper auf Messungen an Holz. Arch. Appl. Mech. 6:8–14.Google Scholar

  • Hu, L.J., Gagnon, S. (2007) X-ray based scanning technique for non-destructive evaluation of finger-joint strength. In: Proc. 15th Int. Symp. NDT Wood. Forest Products Society, Duluth, MN, USA.Google Scholar

  • Jönsson, J.H. (2005) Internal stresses in glulam due to moisture gradients in the grain direction. Holzforschung 59:18–22.Google Scholar

  • Konnerth, J., Gindl, W. (2008) Observation of the influence of temperature on the mechanical properties of wood adhesives by nanoindentation. Holzforschung 62:714–717.Web of ScienceGoogle Scholar

  • Krautkrämer, J., Krautkrämer, H. Werkstoffprüfung mit Ultraschall, Springer, Berlin, Germany, 1986.Google Scholar

  • Niemz, P., Kucera, L.J., Flisch, A., Blaser, E. (1997) Application of computer tomography (CT) on wood defects and decay. Eur. J. Wood Wood Prod. 55:279–280.Google Scholar

  • Saenger, E.H., Gold, N., Saphiro, S.A. (2000) Modeling the propagation of elastic waves using a modified finite-difference grid. Wave Motion 31:77–92.CrossrefGoogle Scholar

  • Sanabria, S.J. (2012) Air-coupled ultrasound propagation and novel non-destructive bonding quality assessment of timber composites, Dissertation (Ph.D. Thesis), No. 20404, ETH Zurich, Switzerland.Google Scholar

  • Sanabria, S.J., Mueller, C., Neuenschwander, J., Niemz, P., Sennhauser, U. (2011a) Air-coupled ultrasound as an accurate and reproducible method for bonding assessment of glued timber. Wood Sci. Technol. 45:645–659.CrossrefWeb of ScienceGoogle Scholar

  • Sanabria, S.J., Furrer, R., Neuenschwander, J., Niemz, P., Sennhauser, U. (2011b) Air-coupled ultrasound inspection of glued laminated timber. Holzforschung 65:377–387.Web of ScienceGoogle Scholar

  • Sanabria, S.J., Furrer, R., Neuenschwander, J., Niemz, P., Sennhauser, U. (2011c) Monitored assessment of structural integrity of multilayered glued laminated timber beams with air-coupled ultrasound and contact ultrasound imaging. In: 17th International Nondestructive Testing and Evaluation of Wood Symposium. University of West Hungary, Sopron, Hungary, Conf. Proc. pp. 359–366.Google Scholar

  • Sanabria, S.J., Wyss, P., Neuenschwander, J., Niemz, P., Sennhauser, U. (2011d) Assessment of glued timber integrity by limited-angle microfocus X-ray computed tomography. Eur. J. Wood Prod. 69:605–617.Web of ScienceGoogle Scholar

About the article

Corresponding author: Jürg Neuenschwander, Electronics/Metrology/Reliability Laboratory, Empa, Swiss Federal Laboratories for Materials Science and Technology, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland, Phone: +41 58 765 4320, e-mail:


Received: 2012-11-14

Accepted: 2013-03-22

Published Online: 2013-04-13

Published in Print: 2013-12-01


Citation Information: Holzforschung, Volume 67, Issue 8, Pages 949–957, ISSN (Online) 1437-434X, ISSN (Print) 0018-3830, DOI: https://doi.org/10.1515/hf-2012-0202.

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