Specifies whether you use a material that has isotropic or anisotropic matrix data. Select Use 7 matrix properties in the drop-down list. Then select Edit matrix properties to display the Matrix properties 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 Do not use matrix properties, or if you select Use 7 matrix properties with materials that have isotropic matrix data, the Tandon-Weng micro-mechanics model is used by default.
Use 6 matrix properties (Obsolete) is included for backward compatibility with old study files.