Thermo-mechanical analysis of wood through an asymptotic homogenisation approach

Vega, Carlos Rojas; Pina, Juan Carlos; Bosco, E.; Flores, Erick I. Saavedra; Guzmán, Carlos Felipe; Yanez, Sergio J.

doi:10.1016/j.conbuildmat.2021.125617

Cited by 8 publications

(1 citation statement)

References 75 publications

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“…In the literature, several multi-scale models for wood have been proposed. For the analysis of softwood (e.g., spruce), which is characterized by a relatively regular cellular configuration, the proposed modelling approaches consider both two-dimensional [27][28][29][30][31] and three-dimensional [9,[32][33][34][35] material structures that include various scales of observation, ranging from the scale of cellulose micro-fibrils to that of annual growth rings. Analytical and/or computational homogenization techniques have been applied for obtaining the effective material properties, occasionally incorporating the dependency of the mechanical properties of the constituent phases on the moisture content.…”

Section: Introductionmentioning

confidence: 99%

A 3D multi-scale hygro-mechanical model of oak wood

Livani

Suiker

Crivellaro

et al. 2023

Preprint

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A multi-scale framework is proposed for the prediction of the macroscopic hygro-elastic properties of oak wood. The distinctive features of the current multi-scale approach are that: i) four different scales of observation are considered, which enables the inclusion of heterogeneous effects from the nano-, micro-, and meso-scales in the effective constitutive behaviour of oak at the macro-scale, ii) the model relies on three-dimensional material descriptions at each considered length scale, and iii) a moisture-dependent constitutive assumption is adopted at the nano-scale, which allows for recovering the moisture dependency of the material response at higher scales of observation. In the modelling approach, oak wood is considered homogeneous at the macro-scale. The meso-scale description considers the cellular structure of individual growth rings with three different densities. At the micro-scale, the heterogeneous nature of cell walls is described by the characteristics of the primary and secondary cell wall layers. Finally, the nano-scale response is determined by cellulose micro-fibrils embedded in a matrix of hemicellulose and lignin. The oak properties at the four length scales are connected via a three-level homogenization procedure, whereby, depending on the geometry of the fine-scale configuration, an asymptotic homogenization procedure or Voigt averaging procedure is applied at each level to determine the effective hygro-elastic properties at the coarse scale. In addition, the moisture ad-sorption isotherms at each scale are constructed from a volume-weighted averaging of the moisture adsorption characteristics at the scale below. The computational results demonstrate that the moisture-dependent, hygro-elastic behaviour of oak wood is predicted realistically at each considered length scale, thereby revealing the influence of the material density, the micro-fibril orientation, and the hygro-elastic properties at the underlying scales. The computed macro-scale properties of oak are in good agreement with experimental data reported in the literature.

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Section: Introductionmentioning

confidence: 99%

A 3D multi-scale hygro-mechanical model of oak wood

Livani

Suiker

Crivellaro

et al. 2023

Preprint

View full text Add to dashboard Cite

show abstract

A 3D multi-scale hygro-mechanical model of oak wood

Livani,

Suiker,

Crivellaro

et al. 2023

Wood Sci Technol

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A multi-scale framework is proposed for the prediction of the macroscopic hygro-elastic properties of oak wood. The distinctive features of the current multi-scale approach are that: (i) Four different scales of observation are considered, which enables the inclusion of heterogeneous effects from the nano-, micro-, and meso-scales in the effective constitutive behavior of oak at the macro-scale, (ii) the model relies on three-dimensional material descriptions at each considered length scale, and (iii) a moisture-dependent constitutive assumption is adopted at the nano-scale, which allows for recovering the moisture dependency of the material response at higher scales of observation. In the modeling approach, oak wood is assumed as homogeneous at the macro-scale. The meso-scale description considers the cellular structure of individual growth rings with three different densities. At the micro-scale, the heterogeneous nature of cell walls is described by the characteristics of the primary and secondary cell wall layers. Finally, the nano-scale response is determined by cellulose micro-fibrils embedded in a matrix of hemicellulose and lignin. The oak properties at the four length scales are connected via a three-level homogenization procedure, for which, depending on the geometry of the fine-scale configuration, an asymptotic homogenization procedure or Voigt averaging procedure is applied at each level to determine the effective hygro-elastic properties at the corresponding coarse scale. In addition, the moisture adsorption isotherms at each scale are constructed from a volume-weighted averaging of the moisture adsorption characteristics at the scale below. The computational results demonstrate that the macro-scale moisture-dependent, hygro-elastic behavior of oak wood is predicted realistically, thereby revealing the influence of the material density, the micro-fibril orientation, and the hygro-elastic properties from the underlying scales. The computed macro-scale properties of oak are in good agreement with experimental data reported in the literature.

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