Is the rule of mixture appropriate for assessing bamboo material properties?

摘要

Bamboo is often described as a functionally graded unidirectional fibre-reinforced composite material. As such, the Rule of Mixture (RoM) is often reported as an appropriate method of capturing longitudinal material and mechanical properties. However the dominant failure mode of bamboo is associated with longitudinal splitting of the culm and is therefore affected by transverse material properties. The efficacy of RoM in the longitudinal direction suggests its adoption in the transverse direction. It is concluded that the transverse behaviour of bamboo is not adequately captured using the often-adopted RoM approach. Experimental, morphological and numerical approaches are presented to better understand the reasons for bamboo not behaving as a unidirectional fibre reinforced material as is uniformly described in the literature. The approach has identified possible causes of the deviation of the observed behaviour - all which require further study. (C) 2020 Elsevier Ltd. All rights reserved.