/FAIL/GENE1

• Minimum hydrostatic pressure based failure criteria:

  $P\le -\left|P_{\min }\right|$

• Maximum hydrostatic pressure based failure criteria:

  $P\ge \left|P_{\max }\right|$

  Where, hydrostatic pressure is computed as:

  $P=-\frac{{\sigma }_{xx}+{\sigma }_{yy}+{\sigma }_{zz}}{3}$

  Note: Hydrostatic pressure is positive in compression.
• Maximum principal stress:

  $\sigma 1\ge \text{SigP1\_max}$ if $\text{SigP1\_max>0}$

  $\sigma 1\ge \left|\text{SigP1\_max}\right|$ if $\text{SigP1\_max<0}$ and positive stress triaxiality value $\eta \text{=}\frac{-P}{{\sigma }_{VONM}}$

• Maximum time ≥ Time_max
• Minimum elementary time step ≤ dtmin (not available with /DT/NODA option).
• Equivalent stress:

  ${\sigma }_{eq}\ge Sig\_max\cdot fct\_I{D}_{sm}\left(\frac{\dot{\epsilon }}{{\dot{\epsilon }}_{sm}}\right)$

• Tuler-Butcher model:

  ${{\displaystyle {\int }_0^t\left[\max \left(0,\sigma 1-Sigr\right)\right]}}^{2}dt\ge K$

  Where, $\sigma 1$ is the principal stress.

• Maximum principal strain:

  $\epsilon 1\ge EpsPS\_max\cdot fct\_I{D}_{ps}\left(\frac{\dot{\epsilon }}{{\dot{\epsilon }}_{ps}}\right)$

• Effective strain:

  $\sqrt{\frac{2}{3}}{\epsilon }_{ij}^{\text{'}}{\epsilon }_{ij}^{\text{'}}\ge Eps\_eff$

  Where, ${\epsilon }_{ij}^{\text{'}}$ is the deviatoric strain.

• Volumetric strain:

  ${\epsilon }_{vol}={\epsilon }_{11}+{\epsilon }_{22}+{\epsilon }_{33}\ge Eps\_vol$

• Minimum principal strain:

  ${\epsilon }_3\le -\left|Eps\_min\right|$

• Maximum tensorial shear strain:

  ${\gamma }_1=\frac{\left({\epsilon }_1-{\epsilon }_3\right)}{2}\ge Shear$

• Mixed-mode fracture criterion:
  • ${\gamma }_{12}=\frac{\left({\epsilon }_1-{\epsilon }_2\right)}{2}\ge fct\_I{D}_{g12}\left(\frac{Siz{e}_{el}}{El\_ref}\right)$ if $-2\le \left(\frac{{\epsilon }_2}{{\epsilon }_1}\right)\le -0.5$
  • ${\gamma }_{13}=\frac{\left({\epsilon }_1-{\epsilon }_3\right)}{2}\ge fct\_I{D}_{g13}\left(\frac{Siz{e}_{el}}{El\_ref}\right)$ if $-0.5\le \left(\frac{{\epsilon }_2}{{\epsilon }_1}\right)\le 1$
  • ${\epsilon }_1\ge fct\_I{D}_{e1c}\left(\frac{Siz{e}_{el}}{El\_ref}\right)$ if $-0.5\le \left(\frac{{\epsilon }_2}{{\epsilon }_1}\right)\le 1$
    Where,

    ${\epsilon }_1$ and ${\epsilon }_2$

    In-plane major and minor strains

    ${\epsilon }_3$

    Through thickness strain

    $Siz{e}_{el}$

    Characteristic element size

• Forming Limit Diagram (FLD):
  • If Itab=1: $({\epsilon }_1,{\epsilon }_2)\ge Tab\_I{D}_{fld}(\frac{\dot{\epsilon }}{Eps\_dot\_fld})$
  • If Itab=2: $({\epsilon }_1,{\epsilon }_2)\ge Tab\_I{D}_{fld}(\frac{Siz{e}_{el}}{El\_ref})$
    Where,

    ${\epsilon }_1$ and ${\epsilon }_2$

    In-plane major and minor strains

    $Siz{e}_{el}$

    Characteristic element size

• The stresses are reduced during Nstep cycles before the element deletion
• Minimum thinning based criterion:
  • if Thinning > 0, shell element is deleted, if the thickness integration point thinning ≤ -|Thinning|,
  • if Thinning < 0, shell element is deleted, if the average thickness thinning ≤ -|Thinning|.
  • For solids, element is deleted, if ${\epsilon }_{zz}$ ≤ -|Thinning|.
• Maximum element temperature ≥ Tmax

Where, $Siz{e}_{el}$ is the characteristic element size.