Elastic behaviour of bamboo at nano- and microscale

Abstract

This paper presents an anatomy-based numerical multiscale approach for modelling the mechanical behaviour of Moso bamboo, addressing limitations in previous research where the intricate microstructure was often simplified. The mechanical response of bamboo culms is predicted at the nano and microscale considering the orthotropic behaviour of cellulose microfibrils in different layers of tissues, deviating from conventional isotropic assumptions. Through nano and microscale finite element models, the impact of chemical composition and microfibril angle on elastic properties of different layers of the fibre and parenchyma cells are explored at two different levels of moisture content. At low moisture content, fibres within vascular bundles exhibit significantly higher longitudinal and transverse elastic moduli compared to parenchyma cells. When the moisture content is high, the properties of the fibre and parenchyma cells are less different. Anisotropic behaviour at the nanoscale contributes to a more accurate prediction of the mechanical properties of bamboo culms at the microscale, particularly in the transverse direction in moist conditions. This study lays the groundwork for forthcoming research in modelling the mechanical behaviour of bamboo culm at meso and macroscales.