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Modelling the viscoelastic mechanosorptive behaviour of Norway spruce under long-term compression perpendicular to the grain

  • Francesco Mirko Massaro EMAIL logo and Kjell Arne Malo
Published/Copyright: April 8, 2019
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Abstract

The effects of variation in humidity coupled with long-term loading give rise to dimensional changes and creep effects in wooden elements. Many wooden products such as cross-laminated timber (CLT) plates as well as many common structural details used in timber engineering are vulnerable to variations in moisture content (MC) as well as to creep effects. This paper addresses the long-term effects in the material modelling of timber by the finite element method (FEM), also considering the viscoelastic and mechanosorptive effects in wood. The model was calibrated using both relaxation tests and creep tests. The results from both long-term compression perpendicular- to-grain tests (relaxation and creep) performed on glulam (GL30c) from Norway spruce (Picea abies) with moisture control are presented in this paper. The material model considers the effect of loading and moisture changes. For realistic comparison, the pith location of each lamella was specified in the numerical analyses. Ultimately, a comparison between the numerical results and the experimental results has been provided, exhibiting an overall good estimation of timber response.

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

  2. Research funding: This study was funded by the WoodWisdom-Net+ project DuraTB (“Durable Timber Bridges”). The support from the funding bodies and partners is gratefully acknowledged.

  3. Employment or leadership: None declared.

  4. Honorarium: None declared.

References

Angst, V., Malo, K.A. (2012) The effect of climate variations on glulam – an experimental study. Eur. J. Wood Wood Prod. 70:603–613.10.1007/s00107-012-0594-ySearch in Google Scholar

Angst, V., Malo, K.A. (2013) Moisture-induced stresses in glulam cross sections during wetting exposures. Wood Sci. Technol. 47:227–241.10.1007/s00226-012-0493-8Search in Google Scholar

Avramidis, S. (1989) Evaluation of “three-variable” models for the prediction of equilibrium moisture content in wood. Wood Sci. Technol. 23:251–257.10.1007/BF00367738Search in Google Scholar

CEN (2013) Timber structures – glued laminated timber and glued solid timber. EN 14080:2013.Search in Google Scholar

CEN (2016) Structural timber – strength classes. EN 338: 2016.Search in Google Scholar

Dahl, K.B. Mechanical Properties of Clear Wood from Norway Spruce. Norwegian University of Science and Technology, Trondheim, 2009.Search in Google Scholar

Dahl, K.B., Malo, K.A. (2009) Linear shear properties of spruce softwood. Wood Sci. Technol. 43:499–525.10.1007/s00226-009-0246-5Search in Google Scholar

Dassault Systemes. Abaqus/CAE 6.14, Vélizy-Villacoublay, France, 2014.Search in Google Scholar

Dinwoodie, J.M. Timber: Its Nature and Behaviour. E & FN Spon – Taylor & Francis, London and New York, 2000.10.4324/9780203477878Search in Google Scholar

Dvinskikh, S.V., Henriksson, M., Mendicino, A.L., Fortino, S., Toratti, T. (2011) NMR imaging study and multi-Fickian numerical simulation of moisture transfer in Norway spruce samples. Eng. Struct. 33:3079–3086.10.1016/j.engstruct.2011.04.011Search in Google Scholar

Fortino, S., Mirianon, F., Toratti, T. (2009) A 3D moisture-stress FEM analysis for time dependent problems in timber structures. Mech. Time-Depend. Mater. 13:333–356.10.1007/s11043-009-9103-zSearch in Google Scholar

Fortino, S., Genoese, A., Genoese, A., Nunes, L., Palma, P. (2013) Numerical modelling of the hygro-thermal response of timber bridges during their service life: a monitoring case-study. Constr. Build. Mater. 47:1225–1234.10.1016/j.conbuildmat.2013.06.009Search in Google Scholar

Hanhijärvi, A. Modelling of creep deformation mechanisms in wood. Technical Research Centre of Finland VTT, Espoo, 1995.Search in Google Scholar

Hanhijärvi, A., Mackenzie-Helnwein, P. (2003) Computational analysis of quality reduction during drying of lumber due to irrecoverable deformation. I: orthotropic viscoelastic-mechanosorptive-plastic material model for the transverse plane of wood. J. Eng. Mech. 129:996–1005.10.1061/(ASCE)0733-9399(2003)129:9(996)Search in Google Scholar

Hunt, D.G. (1994) Present knowledge of mechano-sorptive creep of wood. In: RILEM Report 8 – Creep in Timber Structures. Ed. Morlier, P. E&FN Spon, London. pp. 73–97.Search in Google Scholar

Lagaňa, R., Davids, W.G., Muszyński, L., Shaler, S.M. (2011) Moment-curvature analysis of coupled bending and mechanosorptive response of red spruce beams. Wood Fiber Sci. 43:280–292.Search in Google Scholar

Morlier, P., Palka, L.C. (1994) Basic knowledge. In: RILEM Report 8 – Creep in Timber Structures. Ed. Morlier, P. E&FN Spon, London. pp. 9–42.10.1201/9781482294750-8Search in Google Scholar

Muszyński, L., Lagaňa, R., Shaler, S.M., Davids, W.G. (2005) Comments on the experimental methodology for determination of the hygro-mechanical properties of wood. Holzforschung 59:232–239.10.1515/HF.2005.037Search in Google Scholar

Ozyhar, T., Hering, S., Niemz, P. (2013) Viscoelastic characterization of wood: time dependence of the orthotropic compliance in tension and compression. J. Rheol. 57:699–717.10.1122/1.4790170Search in Google Scholar

Salin, J.-G. (1992) Numerical prediction of checking during timber drying and a new mechano-sorptive creep model. Holz als Roh- und Werkstoff. 50:195–200.10.1007/BF02663286Search in Google Scholar

Santaoja, K., Leino, T., Ranta-Maunus, A., Hanhijärvi, A. Mechano-sorptive Structural Analysis of Wood by the ABAQUS Finite Element Program. VTT, Espoo, 1991.Search in Google Scholar

Schniewind, A.P. (1968) Recent progress in the study of the rheology of wood. Wood Sci. Technol. 2:188–206.10.1007/BF00350908Search in Google Scholar

Sjödin, J. Steel-to-timber dowel joints: influence of moisture induced stresses. Vaxjo University, Vaxjo, 2006.Search in Google Scholar

Svensson, S., Toratti, T. (2002) Mechanical response of wood perpendicular to grain when subjected to changes of humidity. Wood Sci. Technol. 36:145–156.10.1007/s00226-001-0130-4Search in Google Scholar

Toratti, T. Creep of timber beams in a variable environment. Helsinki University of Technology, Espoo, 1992.Search in Google Scholar

Zienkiewicz, O.C., Watson, M., King, I.P. (1968) A numerical method of visco-elastic stress analysis. Int. J. Mech. Sci. 10:807–827.10.1016/0020-7403(68)90022-2Search in Google Scholar


Supplementary Material

The online version of this article offers supplementary material (https://doi.org/10.1515/hf-2018-0218).


Received: 2018-09-21
Accepted: 2019-02-22
Published Online: 2019-04-08
Published in Print: 2019-07-26

©2019 Walter de Gruyter GmbH, Berlin/Boston

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