Analysis of interface granularity in discontinuous fiber composites

摘要

The state-of-the-art in carbon-nanotube/polymer composites produces only moderate increases in modulus and strength over the performance of neat polymers.The nanotube/polymer interface is granulartherefore,models and concepts based on the continuum assumption may no longer apply.This study uses the finite element method to demonstrate the effect of a granular interface in a discontinuous-fiber/polymer composite.Three strategies for bonding are considered,and modulus distribution and effective composite moduli are obtained.It is found that both the shape of the interface-distribution and the total bond density control the effective modulus of the composite.Results imply that it should be beneficial to increase the number of bonding sites,even if that degrades the fiber's modulus,because the optimum composite modulus might be higher because of better load transfer to the fiber.