Failure Criteria

Failure criteria normally predict the failure of a material subjected to multi-axial state of stresses. The Factor of Safety check assesses the safety of the model based on a selected failure criterion.

A material may behave in a ductile or brittle manner depending on the temperature, rate of loading, chemical environment, and the formation process. No single failure criterion is best applicable to a material under all conditions.

You should use all the information available to you about the material to select a failure criterion. You can try more than one stress criterion to assess the safety of the model.

The software supports the following failure criteria:
  • Maximum von Mises Stress Criterion
  • Maximum Shear Stress Criterion
  • Mohr-Coulomb Stress Criterion
  • Maximum Normal Stress Criterion (for composite shells)
For models with composite shells the following failure criteria are supported:
  • Maximum stress criterion
  • Tsai-Hill failure criterion
  • Tsai-Wu failure criterion
See help topic Composite Failure Criteria for more information.