Specifies whether you use a material that has isotropic or anisotropic matrix data. Selectin the drop-down list. Then select to display the dialog box to edit the matrix properties.
When you use matrix properties with materials that have anisotropic matrix data, the Mori-Tanaka micro-mechanics model is used by default.
If you select, or if you select with materials that have isotropic matrix data, the Tandon-Weng micro-mechanics model is used by default.
is included for backward compatibility with old study files.