MAT2/MAT8: question non answered.
MAT2/MAT8: question non answered.
(OP)
I have the same question Vorwald requested a couple of years before and didn´t receive any answer. I quote it:
I have a mat 8 card derived from a composite laminate properties (inverse of the A matrix of the ABD), and I have PSHELL/MAT2 generated from the PCOMP card. The answers are quite a bit different. Can some explain how to compare a MAT8 card to a set of PSHELL/MAT2 cards.
Does anybody know something about it? How to create the MAT2 card which comprise the laminate properties? (With only one MAT2, the command ECHO=PUNCH in Nastran is not what I want because it creates three MAT2 cards)
THANKS A LOT.
I have a mat 8 card derived from a composite laminate properties (inverse of the A matrix of the ABD), and I have PSHELL/MAT2 generated from the PCOMP card. The answers are quite a bit different. Can some explain how to compare a MAT8 card to a set of PSHELL/MAT2 cards.
Does anybody know something about it? How to create the MAT2 card which comprise the laminate properties? (With only one MAT2, the command ECHO=PUNCH in Nastran is not what I want because it creates three MAT2 cards)
THANKS A LOT.





RE: MAT2/MAT8: question non answered.
Regards,
Steve
RE: MAT2/MAT8: question non answered.
Let´s suppose next material with next stacking sequence:
Material properties:
E11=50000 N/mm2
E22=10000 N/mm2
G12=2500 N/mm2
u=0.3
Stacking sequence (6 plies)
(+,-,0)S
I´d create the corresponding mat8 for the material and laminate properties with a pcomp card.
The thing is: Could I create one mat2 for the material and one pshell calling that mat2 for the laminate? In this way, I can manage laminate properties. If I leave the mat8/pcomp relationship, nastran calculates the properties for me, and I don´t want that.
I hope this is what you request. Thanks
RE: MAT2/MAT8: question non answered.
Please explain what you are trying to model and why you don't want to use a PCOMP/MAT8 card set with individual ply input.
RE: MAT2/MAT8: question non answered.
Well, what I want to do is to consider only membrane properties.
The reason why I want to use PSHELL/MAT2 is to have the flexibility of entering the properties I want, not the NASTRAN ones (internal calculations).
My model is a general FEM, not a detailed one.
Thanks again.
RE: MAT2/MAT8: question non answered.
Why not just use membrane elements with a MAT2 entry?
When NEiNastran calculates the MAT12 (solid) entries, it scales/normalizes them as follows:
MAT2 ID2 matrix =[A]/t where t is the laminate thickness
MAT2 ID3 matrix = [D]/t/(1/12*b*t^3)
MAT2 ID5 matrix = [B]/t^2
It may be the same for the MAT2 (shell) entries...If you have any more questions, send me an email: mhayes@mmelab.com
RE: MAT2/MAT8: question non answered.
Yes, that´s what I want to do! Simmulate a laminate with only a MAT2/PSHELL. Is this possible? My idea is to calculate the laminate properties and create a MAT2 (with the E1, E2 and G12 obtained for the laminate, but how?). Then, create a PSHELL calling that MAT2 where only I define the thickness of the laminate.
Do you think make sense? I´d like to have the flexibility of changing the thickness of the laminate in a fast way just changing the thickness in the PSHELL (I guess if I keep orientation percentage I keep the old E1,E2 and G12)...am I right?
Thank you guy!