The Effect of Fiber Diameter on the Strength of Lightweight Composite

Abstract

This paper attempted to investigate the effect of fiber diameter and pursued the possible advantages of utilizing nanofibers within composite materials. An advantage of using nanofibers instead of conventional fibers is to increase the fiber surface area, aside from increasing fiber strength, while keeping the fiber volume fraction same. Several unit cell models were developed where the surface area of fiber was increased gradually using the reduced fiber diameter. For each unit cell model, the axial and shear stress distributions developed in the fiber region were studied. Unit cell models with reduced fiber diameter were found to offer shorter ineffective fiber length representing the region where the fiber stress developed incompletely. As the surface area of fiber increases with reduced fiber diameter, the unit cell models with reduced fiber diameter were also found to offer reduced shear stress. Therefore, if the composite strength depends on fiber surface area, then a composite consisting of fibers with reduced diameter will be stronger than a conventional composite prepared with same volume fraction or conversely will be lighter at the same strength.