Specify material limits for isotropic and transversely isotropic materials on the Material Definition dialog box to determine whether a material has failed under given loading conditions. These limits are stored in the material library. Select None if no failure criterion is required in the Material Definition dialog box.

For Isotropic symmetry—Select one of the following stress quantities from the Failure Criterion area in the Material Definition dialog box:

For Transversely Isotropic symmetry—Select one of the following from the Failure Criterion area in the Material Definition dialog box:

These failure criteria are valid only for 3D shells.

For a static analysis of a model that contains isotropic linear elastic materials, if the value of tensile yield stress has been defined for the material a warning is displayed if the stress in the material exceeds the specified yield stress in any of the non excluded elements. If you have set the failure criterion for the material to either maximum shear stress (Tresca) or distortion energy (von Mises) then those yield conditions are used. If you have not selected a failure criterion then the distortion energy (von Mises) criterion is used.

To view the results, display a fringe plot. If the failure index is equal to or greater than 1, the material has failed.

Failure index measures and results are available only if you select the Stresses check box on the Output tab of the analysis definition dialog boxes.