Stiffness matrices - orthotropy

For predefined plate geometry (ribs, box floor, grillage), the stiffness matrices are calculated on the basis of the geometrical slab parameters.

After you select one of predefined slab geometry types from the list in the New Thickness dialog, click Display to open the Stiffness Matrices - Orthotropy dialog with calculated values of the stiffness matrix. All fields in this dialog are not available. In the New Thickness dialog, the Thicknesses option is cleared and the edit fields for defining thickness are not available, either.

After you select the user-defined option from the list in the New Thickness dialog, you can define an orthotropy matrix. Click Define to open the Stiffness Matrices - Orthotropy dialog to define the stiffness matrix values.

Note: The membrane stiffness matrix D is required only for shell structures; it is not available for plate structures.

If you define matrices of orthotropic stiffness, the Thicknesses option in the New Thickness dialog is not available, but you can access the edit fields for defining thickness.