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Numerical analysis of moisture-induced strains and stresses in glued-laminated timber

  • Sabina Huč ORCID logo EMAIL logo , Staffan Svensson and Tomaž Hozjan
Published/Copyright: November 19, 2019
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Abstract

Changes in relative humidity of the ambient air, RH (%), cause wetting and drying of wood material, which results in non-uniform moisture contents or moisture gradients, and consequently in moisture-induced stresses and strains in the glued-laminated timber (glulam) members. The aim of the present paper is to perform a hygro-mechanical analysis to predict the mechanical behavior of glulam specimens exposed to two RH regimes, causing wetting from 50% to 90% RH and drying from 90% to 50% RH, and compare the numerical to the experimental results. The aims are also to quantitatively analyze the influence of characteristic material parameters required in the multi-Fickian moisture transport model and the mechanical model on moisture-induced strains and stresses in glulam specimens and to determine the possibility of cracking of the material by analyzing the maximum tensile stresses perpendicular to the grain. Accurate numerical predictions of moisture contents and moisture-induced strains are obtained in the glulam specimens during wetting and drying as compared to the experimental results. The influence of a particular characteristic material parameter on moisture-induced strains and stresses is characterized as significant, but not crucial when a rough numerical estimation of the mechanical behavior of the glulam beam exposed to RH changes is required.

  1. Author contributions: All the authors have accepted responsibility for the entire content of this submitted manuscript and approved submission.

  2. Research funding: The financial support by Gunnar Ivarson’s Foundation (Gunnar Ivarsons Stiftelse för Hållbart Samhällsbyggande, GIS) made this work possible. The work of Tomaž Hozjan was supported by the Slovenian Research Agency through the research core funding no. P2-0260, Funder Id: http://dx.doi.org/10.13039/501100004329. The support is gratefully acknowledged.

  3. Employment or leadership: None declared.

  4. Honorarium: None declared.

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Received: 2019-01-30
Accepted: 2019-10-01
Published Online: 2019-11-19
Published in Print: 2020-05-26

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