Following are options related to the ABD matrix:
Add ABD Terms (Default = False)
[Boolean] This backdoor section allows you to artificially stiffen a structure to account for non-structural members that add stiffness to the structure but are not included in the stress analysis. One example of this might be an active cooling panel that carries substantial stiffness.
The figure below illustrates this situation. The hat structure is stiffened (especially in bending) by the additional mass of the active cooling panel which can have a substantial impact on local buckling and other failure analyses of the panel. The ABD matrix representing the active cooling facesheet would be entered through the backdoor data below.
No checking is done to ensure that these extra ABD terms represent a physically realistic structure.
A Added Terms (Default = 0.,0.,0.,0.,0.,0.,0.,0.,0.)
[+Real List] Comma-separated list must include nine terms representing A11, A12, A12, A21, A22, A23, A31, A23, A33. Units are lb/in.
B Added Terms (Default = 0.,0.,0.,0.,0.,0.,0.,0.,0.)
[+Real List] Comma-separated list must include nine terms representing B11, B12, B12, B21, B22, B23, B31, B23, B33. Units are lb-in/in.
D Added Terms (Default = 0.,0.,0.,0.,0.,0.,0.,0.,0.)
[+Real List] Comma-separated list must include nine terms representing D11, D12, D12, D21, D22, D23, D31, D23, D33. Units are lb-in2/in.
Added ABD Offset (Default = 0.0)
[+Real] Offset of the ABD matrix from the default panel reference plane (for stiffened panels, midplane of the upper facesheet). The conversion of ABD terms are shown below. Units are in inches.
A' = A
B' = B + ΔzA
D' = D + 2ΔzB + Δz2A
Limit FEM Material ID Import to 5 digits (Default = False)
[Boolean] Limits the Nastran material IDs used when linking to FEM material to 5 digit. See Linking to FEM Materials.
