Equivalent smeared FE properties of stiffened panel + offset issue

[ohba]

1) Where can I find the equations or references used to calculate the differnents terms of the ABD matrix of a stiffened panel ? These terms are used in the equivalent smeared FE properties when exported to NASTRAN (MAT2 cards).

2) Unlike the unstiffened panels (simple solid laminate element), I think the uni-axial stiffened panel are exported into NASTRAN only in configuration where the nodes are located in the mid plane of the equivalent smeared shell thickness ? Can you confirn that and let me know if there is an option to offset the shell with respect to the node location (other than manually introducing an offset into the CQUAD4 cards) ?

Thank youi

[Ryan]

1) Versions 6.1+ include a panel stiffness HME where this is covered. For now you may refer to the 1993-1994 papers in http://www.hypersizer.com/paper-downloads.html.

2) For stiffened panels (uniaxial, grid, & corrugated family), no shell offsets are exported. You are required to model these components such that the nodes are located at the midplane of the top facesheet.

If you still need to apply an offset to a stiffened panel, there is a backdoor data option in the Component Modification section that allows use to adjust the ABD matrix to get the effect of an offset. This option will be applied to all panels in the project.

(To get to the Backdoor Data, right-click a project name and select Backdoor Data)