Processing of carbon-fibre/epoxy composites with cost-effective interlaminar reinforcement

https://doi.org/10.1016/S0266-3538(97)00114-0Get rights and content

Abstract

A simple and low-cost interlaminar reinforcement method which has been used to improve the delamination resistance of carbon-fibre/epoxy composite laminates is presented in this paper. Chopped Kevlar fibres of 5–7 mm in length and 18 g m−2 in weight-to-area ratio are used as the third-dimension reinforcing fibres. Twelve-ply composite laminates with one, three and five layers of Kevlar fibres have been processed and their compressive strengths measured and compared with those of the plain 12-ply laminates. Reductions in compressive strength due to the presence of chopped Kevlar fibres can be limited to 15% for the reinforced composites with five layers of Kevlar fibres while the delamination toughness is increased by over 100%. Processing pressures are varied to control the thickness of interlaminar Kevlar-fibre/resin layers so that the compressive strengths of the laminates can be tailored. Scanning electron microscopy has been used to study the fracture surfaces after compressive tests to unveil the Kevlar-fibre distribution and the laminate microstructure so that the relationship between compressive strengths and Kevlar-fibre reinforcement can be better understood.

References (49)

  • A.M. Mrse et al.

    Compressive properties of unidirectional carbon fibre laminates: II. The effects of unintentional and intentional fibre misalignments

    Compos. Sci. Technol.

    (1993)
  • S.L. Bazhenov et al.

    Compression failure of unidirectional glass-fibre reinforced plastics

    Compos. Sci. Technol.

    (1992)
  • J. Ivens et al.

    2.5D fabric for delamination resistant composite structure

    Composites

    (1994)
  • D.H. Woolstencroft et al.

    A comparison of test techniques used for the evaluation of the unidirectional Compressive strength of carbon fibrereinforced plastic

    Composites

    (1981)
  • X.Z. Hu et al.

    Mode-I delamination and fibre-bridging in carbon-fibre/epoxy composites with and without PVAL coating

    Compos. Sci. Technol.

    (1993)
  • A.G. Evans et al.

    Kinking as a mode of structural degradation in carbon fibre composites

    Acta Metall.

    (1978)
  • M.R. Piggott

    The effects of fibre waviness on the mechanical properties of unidirectional fibre composites: a review

    Compos. Sci. Technol.

    (1995)
  • E. Wilkinson et al.

    Compressive failure in two types of carbon fibre-epoxide laminates

    Compos. Sci. Technol.

    (1986)
  • R.H. Sigley et al.

    Axial Compressive failure of glass fibre polyester composites under superposed hydrostatic pressure: influence of fibre bundle size

    Compos. Sci. Technol.

    (1992)
  • D.O. Adams et al.

    Compression strength reductions in composite laminates due to multi-layer waviness

    Compos. Sci. Technol.

    (1995)
  • B.N. Cox et al.

    Mechanisms of Compressive failure in 3D composites

    Acta Metall. Mater.

    (1992)
  • G. Hashemi et al.

    The analysis of interlaminar fracture in uniaxial fibre-polymer composite

  • K.M. Liechti et al.

    On the use of laminated beams for the determination of pure and mixed-mode fracture properties of structural adhesives

    J. Adhes.

    (1989)
  • P. Davies

    Protocols for international fracture testing of composites

    (September 1993)
  • Cited by (39)

    • Delamination toughening of composite laminates using weakening or toughening interlaminar patches to initiate multiple delaminations: A numerical study

      2022, Engineering Fracture Mechanics
      Citation Excerpt :

      Although a considerable increase in interface toughness and strength is achieved through thickness reinforcement methods, a considerable degradation in the in-plane properties is also observed [45,51]. Finally, interface toughening can be achieved by interleaving a thin polymeric based layer between the layers in a laminate, which results in an increase in toughness and strength without changing the in-plane properties [57–69]. However, using them at the structural scale in all the interfaces susceptible to damage is currently economically unfeasible.

    • Symmetric and asymmetric intercalation effect on the low-velocity impact behavior of carbon/Kevlar hybrid woven laminates

      2022, Composite Structures
      Citation Excerpt :

      However, due to their layer-by-layer structures [10], CFRP laminates are vulnerable to low-velocity impact loads, resulting in material delamination and a sharp decline in residual strength [11,12]. Methods to improve the impact resistance of laminates include resin toughening [13–16], preform stitching [17], diffused short fiber distribution [18–20], fabric structure design [21–23], ply angle transformation [24], fiber hybrid, etc. For example, adding carbon nanotubes could appropriately improve the overall structural toughness and impact resistance of composite [25], but they increased the matrix viscosity and made the curing process more difficulty [26,27].

    • Recent Advances and Applications of Thermoset Resins

      2022, Recent Advances and Applications of Thermoset Resins
    View all citing articles on Scopus
    View full text