Moisture transport in laminated wood and bamboo composites bonded with thin adhesive layers – A numerical study
Sustainable materials such as laminated wood and bamboo composites are increasingly being used in the construction of green buildings across the world. Such products may be exposed to cyclic environmental conditions and exhibit moisture-induced damage. Predicting the moisture profile variation with time is the first step towards understanding the performance of such products under combined mechanical and environmental loads. The main objective of this study is to develop and validate an efficient, physically-based tool to elucidate the transient moisture transport in layered orthotropic composites made from wood and bamboo. To ensure the capability of the framework in capturing the essential moisture transport mechanisms, a comprehensive literature review was conducted to determine the most critical parameters in moisture transport phenomena in laminated panels. Thermal moisture analogy theory was used for simulating the moisture transport across the composite material cross-section. The analogy approach was first verified based on a simple one-dimensional (1-D) analytical model. Then, moisture profiles in various small laminated composite panels were predicted using a three-dimensional (3-D) finite element model developed in ANSYS Workbench©. Unlike previous studies, the moisture adsorption curve of the material was used instead of employing surface emission coefficient to estimate moisture flux at the surfaces. Results were compared against experimental data for validation purposes. A series of parametric studies were conducted using the validated model to highlight quantitatively the effect of glue line and the constituents’ (i.e. wood/bamboo and adhesive) physical properties on the moisture transport across the composite panel. The model predictions showed a remarkably good description of the data reported in the literature. For the first time, the results showed that the choice of adhesive along with the combination of wood/bamboo physical properties can significantly affect the panel’s moisture profile even after 14 days under similar environmental conditions.
» Author: Zahra Afshari, Sardar Malek
» Publication Date: 18/07/2022
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This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement Nº 768737