I saw your power point presentation on buckling of stiffened panels recently.I have a question that makes me very confused and I hope to get your reply.
The ppt shows that SGs of different dimensions give the same stiffness matrix,the 2D SG is a surface without thickness,the 3D SG has length, width and height,how to set the length of the 3D SG so that the stiffness matrix is the same as that of the 2D SG.
As I mentioned in another post, the length in y2 direction of the 3D SG (red line) does not matter, it is uniform and can be arbitrary.
Quote -
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To answer your question, that 3D SG in your figure specifically is in solid element, the length does not matter, can be arbitrary (even zero).
With that being said, if the length of such 3D SG becomes zero, it is equivalent to a 2D SG (in shell element), which will give you the same constitutive relations (6x6 plate stiffness). Actually, the 2D SG is the fundamental building block, or a unit cell, that contains all the necessary information for constitutive modeling in this case, the length (your red line) is only required for 3D SG.
Consider here the 3D SG as an extrusion from 2D SG along your red line, nothing new.
However, the 2D SG only works when the stiffeners are uniform in the longitudinal direction, if a cross-type stiffeners are present (stiffeners are pointing both directions), then SG has to be in 3D.
"
Link to the post: https://cdmhub.org/groups/yugroup/forum/default-section/msgswiftcomp/4430
Anonymous @ on
Hello, Ning Liu
I saw your power point presentation on buckling of stiffened panels recently.I have a question that makes me very confused and I hope to get your reply.
The ppt shows that SGs of different dimensions give the same stiffness matrix,the 2D SG is a surface without thickness,the 3D SG has length, width and height,how to set the length of the 3D SG so that the stiffness matrix is the same as that of the 2D SG.
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Ning Liu @ on
As I mentioned in another post, the length in y2 direction of the 3D SG (red line) does not matter, it is uniform and can be arbitrary.
Quote -
"
To answer your question, that 3D SG in your figure specifically is in solid element, the length does not matter, can be arbitrary (even zero).
With that being said, if the length of such 3D SG becomes zero, it is equivalent to a 2D SG (in shell element), which will give you the same constitutive relations (6x6 plate stiffness). Actually, the 2D SG is the fundamental building block, or a unit cell, that contains all the necessary information for constitutive modeling in this case, the length (your red line) is only required for 3D SG.
Consider here the 3D SG as an extrusion from 2D SG along your red line, nothing new.
However, the 2D SG only works when the stiffeners are uniform in the longitudinal direction, if a cross-type stiffeners are present (stiffeners are pointing both directions), then SG has to be in 3D.
"
Link to the post: https://cdmhub.org/groups/yugroup/forum/default-section/msgswiftcomp/4430
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Ning Liu @ on
Correction - the red line is along y1 direction (longitudinal). And so y2 is transverse, y3 is through the thickness of plate.
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Anonymous @ on
Thank you very much for your reply.I got it.
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