Senile coconut palms: Functional design and biomechanics of stem green tissue

Abstract

This study aims at determining the biomechanical behaviour and functional design, at integral level of hierarchical structure, of senile coconut palms (greater than 80 years old). To achieve the objectives, 46 stress/strength analyses were performed on characteristic coconut palm stem green tissues (referred to as cocowood herein) by means of three dimensional finite element analysis (FEA). To estimate the material damage produced when the stresses rose beyond the material strength, the Tsai-Hill failure criterion was used; the progressive material failure was predicted and mapped for seven wind speeds of different categories. Parametric analyses were performed to further analyse the influence of fibrovascular bundle orientations and density distribution on the cocowood stem functional design. The research outcomes showed an optimum orientation of characteristic fibrovascular bundles and an improved cocowood structure in terms of mechanical efficiency and capacity to resist high wind loadings. The analyses allowed for a better understanding of the cocowood biomechanics and functional design, especially the significance of its structural-mechanical advantage over other palm species and trees. As no similar research on the cocowood biomechanics using FEA had been conducted before, the knowledge advanced from the current study has far-reaching implications for enhancing wood materials from a biomimetic perspective.