Tensile strength of windmill palm (Trachycarpus fortunei) fiber bundles and its structural implications

Trachycarpus fortunei (windmill palm) is one of the most widely distributed and widely used palms in East Asia. In order to find further uses for the palm’s fibers, however, more information on their mechanical and anatomical properties is needed. With this in mind, tensile strength and Young’s modulus of windmill palm fiber bundles were investigated and the structural implications considered. The anatomical features in cross-section, the fracture mode, and the microfibril angle (MFA) of natural fiber bundles were determined. The transverse sectional area occupied by fibers in a fiber bundles (SF) contributes to mechanical strength in practice. It was found that the ratio of SF to the transverse sectional area of a fiber bundle dramatically increases with a decrease in bundle diameter. Therefore, tensile strength and Young’s modulus of an individual fiber bundle in this species increase in parallel with a decrease in fiber bundle diameter. The observed MFA features might have a relationship with the biomechanical movements of fiber bundles in the windmill palm. The potential uses of windmill palm fibers have been discussed.