Specifying fracture criterion properties for crack propagation

You can specify the fracture criterion that is used to model crack propagation using the virtual crack closure technique (VCCT) in an Abaqus/Standard model. The fracture criterion specifies the critical energy release rates. For more information, see Crack Propagation Analysis.

  1. From the main menu bar, select InteractionPropertyCreate.
  2. In the Create Interaction Property dialog box that appears, do the following:

  3. Click Continue to close the Create Interaction Property dialog box.
  4. From the menu bar in the contact property editor, select MechanicalFracture Criterion.
  5. Select the Type of criterion for crack propagation along initially partially bonded surfaces—the virtual crack closure technique (VCCT) criterion or the enhanced virtual crack closure technique (Enhanced VCCT) criterion. The virtual crack closure techniques are available only in an Abaqus/Standard analysis.
  6. If you are using the crack propagation criterion in an enriched region, choose the direction of crack growth relative to the local 1-direction when the fracture criterion is satisfied. The crack can extend at a direction normal to the direction of the maximum tangential stress (default), normal to the element local 1-direction, or parallel to the element local 1-direction.
  7. Select the mixed mode behavior:

    • Select BK to specify the fracture energy as a function of the mode mix by means of the Benzeggagh-Kenane mixed mode fracture criterion.

    • Select Power to specify the fracture energy as a function of the mode mix by means of a power law mixed mode fracture criterion.

    • Select Reeder to specify the fracture energy as a function of the mode mix by means of the Reeder mixed mode fracture criterion.

  8. If desired, specify the tolerance within which the crack propagation criterion must be satisfied. The default is 0.2.
  9. If desired, specify the tolerance within which the unstable crack propagation criterion must be satisfied to allow multiple nodes at and ahead of the crack tip to debond without cutting back the increment size in one increment when the VCCT criterion is satisfied for an unstable crack problem. The default value is infinity.
  10. If desired, specify the viscosity coefficient used in the viscous regularization. The default value is 0.0.
  11. If you selected VCCT for the type of fracture criterion, define the energy release rates (for both crack onset and crack propagation) at each mode: GIC, GIIC, and GIIIC.
  12. If you selected Enhanced VCCT for the type of fracture criterion, do the following:

    • Define the energy release rates for crack onset at each mode: GIC, GIIC, and GIIIC.

    • Define the energy release rates for crack propagation at each mode: GICP, GIICP, and GIIICP.

  13. If you selected either Reeder or BK as the fracture criterion, define the exponent in the Reeder law or the Benzeggagh-Kenane model, η.
  14. If you selected Power as the fracture criterion, define the three exponents in the power law model, am, an, and ao.
  15. Toggle on Use temperature-dependent data if the fracture criterion is dependent on temperature.
  16. Click the arrows to the right of the Number of field variables field to specify the number of field variables on which the fracture criterion depends.
  17. Enter the required data in the data table provided.
  18. Click OK to create the contact property and to exit the Edit Contact Property dialog box. Alternatively, you can select another contact property option to define from the menus in the Edit Contact Property dialog box.