A Fundamental Study Of The Fracture And Fatigue Characteristics Of Single Wood Pulp Fibres

"The engendered conclusions may be summed up as follows. From a litany of tenuously-oriented microcracks, dominant macrocracks propagate along the axis of the fibre which may sharply deflect in the presence of natural bias (e.g. pits in the fibre wall). The material property degradation characteristics further include: volumetric expansion due to internal fibrillation in the cell wall, extensive external fibrillation, gradual delamination of the layers and partial peeling-off of the cell wall material. Cumulative damage due to cyclic shear is shown to be the most significant, further supported by the high structural collapsibility of the fibre wall layers. The mechanisms of fracture are either due to the development of transverse cracks at regions of high stress concentration (such as bordered pits), or owing to the gradual slippage of the fibre wall layers." --