On the mechanisms of cumulative damage and fracture in native cellulose fibres

The viscoelastic character of cellulosic fibers indicates that energy is absorbed, when subjected to cyclic mechanical action, both in large plastic deformations and small reversible viscoelastic effects. The latter only produces heat in the system, whereas it is the plastic deformations that are basically responsible for making the fibers flexible. The application of the laws of mixtures may prove useful in explicating the framework-matrix interaction within the composite tube. It is suggested that, in each layer, the reinforcing cellulose microfibrils diminish the role of the cementing matrix as a load-bearing component by continually transferring the stress to adjacent layers, and hence acting to reduce the energy losses therein.