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Fracture characterisation of green glued-polyurethane adhesive bonds in Mode I

Sterley, Magdalena; Serrano, Erik LU and Enquist, Bertil (2013) In Materials and Structures 46(3). p.421-434
Abstract
<p>Unseasoned (green) spruce timber side boards of size 25 × 120 × 600 mm were flatwise-glued with a one-component PUR adhesive. Glued pairs of boards were then kiln-dried to 12 % moisture content. A special small-scale specimen for testing the fracture properties of the adhesive bond in Mode I was developed in order to evaluate the adhesive bond properties. The complete force versus deformation curve, including both the ascending and the descending parts, could be obtained with these small-scale specimens, enabling the strength and fracture energy of the bond line to be calculated. In addition, the fractured specimens were examined by scanning electron microscope. Results show that both the tensile strength and the fracture energy... (More)
<p>Unseasoned (green) spruce timber side boards of size 25 × 120 × 600 mm were flatwise-glued with a one-component PUR adhesive. Glued pairs of boards were then kiln-dried to 12 % moisture content. A special small-scale specimen for testing the fracture properties of the adhesive bond in Mode I was developed in order to evaluate the adhesive bond properties. The complete force versus deformation curve, including both the ascending and the descending parts, could be obtained with these small-scale specimens, enabling the strength and fracture energy of the bond line to be calculated. In addition, the fractured specimens were examined by scanning electron microscope. Results show that both the tensile strength and the fracture energy of the green glued PUR adhesive bonds were equal to those of the dry glued bonds. The methodology developed and used in the present study gives new possibilities for analysis of the mechanical behaviour of wood adhesive bonds, and particularly of their brittleness and its correlation with the type of fracture path. This is in sharp contrast to the use of standardised test methods (e.g. EN 302, ASTM D905) with specimens having relatively large glued areas. Using such types of specimens, it is not possible to obtain the complete force versus deformation response of the bond. In addition, when using such test methods, failure takes place in the wood or in the fibres near the bond, thus making it impossible to obtain detailed information about the bond line characteristics.</p> (Less)
Please use this url to cite or link to this publication:
author
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Wood adhesive, Bond line, Fracture, Ductility, Green gluing, Polyurethane
in
Materials and Structures
volume
46
issue
3
pages
421 - 434
publisher
Springer
external identifiers
  • scopus:84893644705
ISSN
1359-5997
DOI
10.1617/s11527-012-9911-5
language
English
LU publication?
no
id
6d290499-285f-421c-83ea-f623f615a301 (old id 4770312)
date added to LUP
2014-11-10 07:41:55
date last changed
2018-05-29 10:00:34
@article{6d290499-285f-421c-83ea-f623f615a301,
  abstract     = {&lt;p&gt;Unseasoned (green) spruce timber side boards of size 25 × 120 × 600 mm were flatwise-glued with a one-component PUR adhesive. Glued pairs of boards were then kiln-dried to 12 % moisture content. A special small-scale specimen for testing the fracture properties of the adhesive bond in Mode I was developed in order to evaluate the adhesive bond properties. The complete force versus deformation curve, including both the ascending and the descending parts, could be obtained with these small-scale specimens, enabling the strength and fracture energy of the bond line to be calculated. In addition, the fractured specimens were examined by scanning electron microscope. Results show that both the tensile strength and the fracture energy of the green glued PUR adhesive bonds were equal to those of the dry glued bonds. The methodology developed and used in the present study gives new possibilities for analysis of the mechanical behaviour of wood adhesive bonds, and particularly of their brittleness and its correlation with the type of fracture path. This is in sharp contrast to the use of standardised test methods (e.g. EN 302, ASTM D905) with specimens having relatively large glued areas. Using such types of specimens, it is not possible to obtain the complete force versus deformation response of the bond. In addition, when using such test methods, failure takes place in the wood or in the fibres near the bond, thus making it impossible to obtain detailed information about the bond line characteristics.&lt;/p&gt;},
  author       = {Sterley, Magdalena and Serrano, Erik and Enquist, Bertil},
  issn         = {1359-5997},
  keyword      = {Wood adhesive,Bond line,Fracture,Ductility,Green gluing,Polyurethane},
  language     = {eng},
  number       = {3},
  pages        = {421--434},
  publisher    = {Springer},
  series       = {Materials and Structures},
  title        = {Fracture characterisation of green glued-polyurethane adhesive bonds in Mode I},
  url          = {http://dx.doi.org/10.1617/s11527-012-9911-5},
  volume       = {46},
  year         = {2013},
}