Fiber volume ratio - Wikipedia Importance of Fiber Volume Fraction. The amount of fiber in a fiber reinforced composite directly corresponds with the mechanical properties of the composite. Theoretically the maximum fiber ratio of round fibers that can be achieved in a composite is 90.8% if the fibers are in a unidirectional hexagonal close packed configuration. Fibre Volume Fraction - an overview | ScienceDirect Topics Local preform fiber volume fraction, V f, is calculated based on the change in volume of a cell of the draped fishnet, as a function of the shearing angle, α. The shearing angle, α, is defined in Figure 12 .