Coupling Between Diffusion and Damage

It was noted that fluid-induced swelling would induce non-uniform hygral stresses in the regions occupied by the polymeric phase in fiber-reinforced composites. This non-uniformity stems from the inherent geometry of the fiber-matrix cross section and is enhanced by the random distribution of fibers positioned therein, as shown in Fig. 3.5 (Daniel and Ishai 2005) 

The aforementioned stress concentrations, some of which are tensile, will induce micro-cracks within the composite that increase its fluid absorption capacity. Several models on this topic are presented in Sect. 5.7. 

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