Effective Dissipative Properties of a Whiskered Layer in Modified Fibrous Composites With Whiskered Fibres

Abstract

It is known that the mechanical properties of fiber-reinforced composites are controlled by the conditions of contact between the fiber and the matrix. In this regard, great efforts of mechanics are directed to developing various techniques to improve the quality of the interface. The most common are: modification of the fiber surface, improvement of chemical interactions, or the addition of a third phase (interfacial layer) between the fiber and the matrix. The most common are: modification of the fiber surface, improvement of chemical interactions, or a third phase (interfacial layer) between the fiber and the matrix. In this study, the authors aim to examine the effective dynamic properties of a whiskered layer of fibers in modified composites, taking into account the structural characteristics of the interfacial layer – its thickness – length of whiskers, volumetric content of whiskers, and their mechanical properties. The dynamic performance of the whiskered layer surrounding the base fiber in modified composites was estimated. The whiskered layer is considered a fibrous composite formed by nanoscale whiskers grown on the surface and a matrix. An epoxy binder or a viscoelastic polymer is considered as a matrix. An approximate model was used. The effective characteristics of the whiskered layer were modeled and determined as the properties of a transversally isotropic fibrous system with the isotropy axis coinciding with nanowhiskers in the whiskered layer. A feature of the whiskered layer is that the density of whiskers varies with distance from the fiber surface. Therefore, it depends on the length of the nanowhiskers (the thickness of the interfacial layer). In this case, it turns out that the bulk for the matrix in the whiskered layer, even at the maximum density of nanowhiskers grown on the fiber surface and for sufficiently thin interfacial layers, is very significant. Fuzzy fiber composite, nanofibers, epoxy binder, damping properties.