Rheology data for Norway spruce

This repository enables exploration of rheological data on wood. It is based on the following research works: Maas, J.M. and Wittel, F.K. (2026) “From elasticity to creep: orthotropic moisture-dependent rheology of Norway spruce.” Holzforschung, 80(7), pp. 514–542. Available at: https://doi.org/10.1515/hf-2026-0009. Maas, J.M. and Wittel, F.K. (2026) “Orthotropy of wood mechanosorption in Norway spruce.” engrXiv preprint. Available at: https://doi.org/10.31224/8738 Please cite the respective source when using data from this repository. See the acknowledgement section for more information. Description The data in this repository comprise: Species: Norway spruce Properties: elasticity, strength, plasticity, viscoelasticity, hygroexpansion, sorption, density, mechanosorption Anatomical directions: compression/tension R, T, L; shear RT, TR, RL, LR, TL, LT Data format: experimental data points in tables (in folder data), exploration of fitting data via widgets (in Jupyter notebooks) All data originate from samples of the same tree, i.e., they are consistent with one another. To explore the data, open any notebook in Jupyter Lab and select "Restart Kernel and Run All". This creates Jupyter widgets that enable interactive exploration of the data. Content This repository contains the following folders and files. Folders: data: Raw data required for the notebooks to run. figures: Figures used in the Markdown explanations of the notebooks and figures created by some of the notebooks. utils: Helper functions used by the notebooks. Notebooks: 01_elasticity.ipynb: Allows for visualization and export of fits and experimental data points for the elastic stiffnesses. 02_strength.ipynb: Allows for visualization and export of fits and experimental data points for the strength parameters. 03_plasticity.ipynb: Allows for visualization and export of fits and experimental data points for the plastic deformations. 04_viscoelasticity.ipynb: Allows for visualization and export of fits and experimental data points for the viscoelasticity parameters, i.e., Kelvin-Voigt coefficients and fits of the time-moisture superposition principle. 05_sorption.ipynb: Visualizes the density distribution, hygroexpansion, and sorption isotherm of the tree from which the samples are obtained. 06_mechanosorption.ipynb: Allows for visualization and export of fits and experimental data for the mechanosorptive parameters, i.e., Kelvin-Voigt coefficients. Installation Create a Python 3.10.14 environment and install the packages in requirements.txt. Example for Linux and Anaconda: Create environment: conda create --name wood-rheology python=3.10.14 Enter Python environment: conda activate wood-rheology Navigate to the repository and install packages: pip3 install -r requirements.txt Launch Jupyter Lab: jupyter lab Alternatively, this repository can be run directly via RenkuLab at https://renkulab.io/p/jomaas/wood-rheology. Usage Each notebook is designed so that the widgets can be used by running the complete notebook via "Restart Kernel and Run All". The experimental data points can be extracted from the tables in the folder data. To do so, each widget has an "export" button that exports the data points of the current selection as a CSV table. Authors and acknowledgment Authors: J. M. Maas (ORCID: 0000-0001-5679-7352), F. K. Wittel (ORCID: 0000-0001-8672-5464) Please cite the corresponding paper when using data from this repository: For data related to the notebooks 01_elasticity.ipynb, 02_strength.ipynb, 03_plasticity.ipynb, 04_viscoelasticity.ipynb, 05_sorption.ipynb: Maas, J.M. and Wittel, F.K. (2026) “From elasticity to creep: orthotropic moisture-dependent rheology of Norway spruce.” Holzforschung, 80(7), pp. 514–542. For data related to the notebook 06_mechanosorption.ipynb: Maas, J.M. and Wittel, F.K. (2026) “Orthotropy of wood mechanosorption in Norway spruce.” EngrXiv preprint. https://doi.org/10.31224/8738 This work was financially supported by the Swiss National Science Foundation (SNSF grant 200021_192186, "Creep behavior of wood on multiple scales"), which we gratefully acknowledge. License All programming code/scripts that are part of this data set are licensed under the MIT License https://opensource.org/license/MIT. All research data that accompanies the programming code/scripts are licensed under the Creative Commons license CC BY 4.0 https://creativecommons.org/licenses/by/4.0/deed.en.