Fibre volume fractions of library values?

- May 27, 2020 at 3:40 pm
  
  Leigh
  Subscriber
  
  Hi,
  
  I am using the material properties (taken from the 'composite materials' 'Data Sources') below in a static structural analysis:
  
  The 'Epoxy E-Glass Wet' ply type is listed as 'Regular' but it must be UD since Ex > (Ey = Ez)
  
  I am assuming that 'Wet' means not pre-preg (as in Hand LayUp &/or Vac Bagged etc)
  
  I am trying to find out which FVF (Vf, fibre volume fractions) each of these material properties correspond to
  
  Up to now I have been using the equation linking the densities of the constituent materials (epoxy, E-glass and 230GPa Carbon) with the composite density to estimate the FVF's of these composites from the given composite densities:
  
  Density Composite = (Density Fibres*FVF) + [Density Resin*(1-FVF)]
  
  This has given me the following (ESTIMATED) FVF's:
  
  Epoxy E-Glass WET (must be UD)          FVF ≈ 0.50
  Epoxy Carbon UD (230 Gpa) Wet           FVF ≈ 0.65
  Epoxy Carbon Woven (230 Gpa) Wet     FVF ≈ 0.55
  
  These seem reasonable values, depending on the exact production method used in each case
  
  However, the equation above does not consider voids etc (which depend heavily on the production process, so calculating or estimating them is difficult) and hence can only give estimates
  
  So, my question is ...
  
  Does anyone have any more info on the basis of these material property values (especially concerning FVF and production method) &/or can point me in the right directions to find out?
  
  Thanks