$f_E$	the elasticity factor
$f_{\sigma }$	the resistance factor
$f_u$	the uniformity factor
E	the elasticity modulus of analyzed sample
$E_{ideal}$	the elasticity modulus of the material considered to be ideal, without non-uniformities
$E_s$	the elasticity modulus of a layer without discontinuities
$E_r$	the elasticity modulus of the resin
$E_k\left(x\right)$	the elasticity modulus of the layer k in the section of the abscissa x
${\sigma }_r$	the tensile strength of the analyzed sample material
${\sigma }_r^{\left(s\right)}$	the tensile strength of the reference material
${\sigma }_k\left(x\right)$	the normal tension in layer k in the section of the abscissa x
${\sigma }_{rideal}$	the tensile strength of the material considered as ideal, without non-uniformities
$\epsilon \left(x\right)$	the characteristic deformation in layer k in the section of the abscissa x
$h_k$	the thickness of the layer k
l	the bar length
$l_0$	the interruption length
b	the bar width
h	the bar thickness.