anchor.diff:  
   ! Parameters
   
  +! ===> START INPUT DATA
  +
   Vf = ! [-] Fiber volume fraction
   
   t = 1             ! [mm] 2t = thickness of the element
  
positive.code: GL = ! [MPa] UD in-plane shear modulus
  GT = ! [MPa] UD transverse shear modulus
  
  L = t/rhon        ! [mm] length of the RVE
  a = atRatio*t     ! [mm] 2a = crack length
  
  
negative.code: atRatio = 0.1     ! [-]  ratio of crack length to main ply thickness
  rhon = 0.01       ! [-]  normalized crack density
  daOvera = 0.05    ! [-]  ratio of crack increment (i.e. crack tip element size) to crack length
  epsx = 0.01       ! [-]  applied strain
  
  EL = ! [MPa] UD longitudinal Young's modulus
  ET = ! [MPa] UD transverse Young's modulus
  