Effect of quality, porosity and density on the compression properties of cork
Type
article
Creator
Publisher
Identifier
ANJOS, O. ; PEREIRA, H. ; ROSA, M.E. (2008) - Effect of quality, porosity and density on the compression properties of cork. Holz Roh Werkst. 66. p. 295-301.
Title
Effect of quality, porosity and density on the compression properties of cork
Einfluss von Qualit¨at, Porosit¨at und Dichte auf die Druckeigenschaften von Kork
Einfluss von Qualit¨at, Porosit¨at und Dichte auf die Druckeigenschaften von Kork
Subject
Cork
Porosity
Density
Porosity
Density
Date
2013-07-18T14:50:16Z
2013-07-18T14:50:16Z
2008
2013-07-18T14:50:16Z
2008
Description
DOI 10.1007/s00107-008-0248-2
The compression properties of cork were studied on samples obtained from cork planks of two commercial quality classes (good and poor quality), with densities ranging from 0.12–0.20g cm−3 and porosities from0.5 to 22.0%. The stress-strain curves were characterized by an elastic region up to approximately 5% strain, followed by a large plateau up to 60% strain caused by the progressive buckling of cell walls, and a steep stress increase for higher strains corresponding to cell collapse. The direction of compression was a highly significant factor of variation, with cork showing higher strength for the radial compression. Density influenced compression and cork samples with higher density showed overall larger resistance to compression in the three directions. In the elastic region, an exponential model of Young’s modulus in function of cork density could be adjusted. The effect of porosity on compression was small and the stress-strain curves were similar regardless of the porosity of the samples, although there was a trend toward an overall increase of stress with porosity for higher strains. Porosity was characterised by a high variability in the anatomical features of the lenticular filling material and the presence of collapsed and thick walled lignified cells. The inclusion of a porosity parameter for the modelling of the elastic modulus did not improve the prediction obtained with densitybased models. There was no significant difference in the compression properties of cork samples obtained from cork planks of good and poor quality classes.
The compression properties of cork were studied on samples obtained from cork planks of two commercial quality classes (good and poor quality), with densities ranging from 0.12–0.20g cm−3 and porosities from0.5 to 22.0%. The stress-strain curves were characterized by an elastic region up to approximately 5% strain, followed by a large plateau up to 60% strain caused by the progressive buckling of cell walls, and a steep stress increase for higher strains corresponding to cell collapse. The direction of compression was a highly significant factor of variation, with cork showing higher strength for the radial compression. Density influenced compression and cork samples with higher density showed overall larger resistance to compression in the three directions. In the elastic region, an exponential model of Young’s modulus in function of cork density could be adjusted. The effect of porosity on compression was small and the stress-strain curves were similar regardless of the porosity of the samples, although there was a trend toward an overall increase of stress with porosity for higher strains. Porosity was characterised by a high variability in the anatomical features of the lenticular filling material and the presence of collapsed and thick walled lignified cells. The inclusion of a porosity parameter for the modelling of the elastic modulus did not improve the prediction obtained with densitybased models. There was no significant difference in the compression properties of cork samples obtained from cork planks of good and poor quality classes.
Access restrictions
restrictedAccess
Language
eng
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