Elastic Properties of Polymer Systems Reinforced with Short Organic Fibers

This paper addresses the experimental and theoretical investigations of mechanical properties of polymer resins reinforced with natural fibers. These materials have potentially a wide area of applications and relatively low cost because they are made of inexpensive resins and fibers obtained from plants available in the Mexican desert. We present the results of experimental investigations of elastic properties and strength of composites based on three types of polymer resins reinforced with natural fibers of Palma Zamandoca. Theoretical analysis of effective elastic and strength properties of short-fiber matrix composites is given based on the advanced self-consistent scheme permitting to account for interactions between fibers. The method utilizes the idea of introducing the effective strain field which affects every inclusions in the composite. In distinction to the traditional forms of the effective (i.e., self-consistent) field method we assume that the effective field is not constant and the same for all fibers but rather depends on the orientation of each of them. This allows to take into account the characteristics of the spatial distributions of fibers in the volume of composite. The scheme utilizes the asymptotic solution of elastic problem for rigid cylindrical bar. The results of theoretical analysis are compared with extensive experimental data on composites with natural fibers manufactured and tested by the authors as well as with the data for composites with inorganic fibers (e.g., glass and carbon fibers) available in literature.