Abstract:
Systematic experimental investigation is carried out to characterize the effect of carbon nanotubes
(CNTs) grafting on the average mechanical properties and mode-II fracture toughness of
carbon fiber reinforced plastics (CFRPs). Two growth strategies are used in a chemical vapor
deposition (CVD) reactor to ensure uniform coverage of both sides of fiber fabric with CNTs.
Improvement in interlaminar shear strength of CFRP due to incorporation of CNTs is found to be
sensitive to the uniformity of grafted CNTs on the fabric surface. It is shown that the use of
optimum CNT grafting strategy on the fiber surfaces leads to a significant improvement in
flexural properties and mode-II fracture toughness of conventional CFRPs. However, the use of
CNT grafted laminas in the composite laminate does not alter the response of CFRP under the
uniaxial tensile loading. Scanning electron microscopy (SEM) analysis of failed composite coupons
after mode-II testing reveals that different failure mechanisms operate in composite laminate
fabricated with or without the use of CNT grafted laminas.
