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6066 Laminate Min SR

6066 Laminate Min SR

6066 Laminate Min SR

Hello ~ Does anyone have a snap shot or a document you could refer me to for understanding how Nastran is computing the output vector "6066 - Laminate Min Strength Ratio" for a 2D orthotropic laminate?


RE: 6066 Laminate Min SR


Look for "NASTRAN Section1 Composites" in a web search engine. You should get MSC NASTRAN's "Introduction to composites" presentation.
Look for the failure theories. Most of them require solving a 2nd degree equation => min strength ratio is the lowest solution.

There is a trap: I think in a regular sol101 MSC NASTRAN will keep the positive SRatio, not the abs lowest. So if the sign of your loadcase has no meaning, i.e. if you implicitely want to compute both + and - your loadcase all in once, I think a regular sol101 will trick you, you need to pass both cases (+ and -).

Strangely this is not true for solid composites... And as for NX NASTRAN I'm not sure.


RE: 6066 Laminate Min SR


To learn more about Strength Ratio calculation refers to this document:

FEMAP\v111\nastranhelp\NXNastran\nast\misc\doc\docs\en_US\tdoc\pdf\User.pdf Chapter 24.3.

Seif Eddine Naffoussi, Stress Engineer
33650 Martillac û France

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