CSHEAR Element Output
CSHEAR Element Output
(OP)
Dear All,
I looking at the nastran output of shear panel element CSHEAR and I confused with the Shear-IJ output, where I=1..4, J=1..4
Example: So Shear-IJ, what units it has? lb/in? Also what is kick output? Thanks. Kristina.
Sorry about how it looks, when I paste it it shows good format but preview does not show good format.
F O R C E S A C T I N G O N S H E A R P A N E L E L E M E N T S (CSHEAR)
====== POINT 1 ====== ====== POINT 2 ====== ====== POINT 3 ====== ====== POINT 4 ======
ELEMENT F-FROM-4 F-FROM-2 F-FROM-1 F-FROM-3 F-FROM-2 F-FROM-4 F-FROM-3 F-FROM-1
ID KICK-1 SHEAR-12 KICK-2 SHEAR-23 KICK-3 SHEAR-34 KICK-4 SHEAR-41
0 40069 2.50181E+02 4.25804E+01 -1.47293E+02 2.94144E+00 1.22708E+02 2.62269E+01 -1.63647E+02 1.30414E+02
0.0 2.92114E+01 0.0 2.92114E+01 0.0 2.92114E+01 0.0 2.92114E+01
I looking at the nastran output of shear panel element CSHEAR and I confused with the Shear-IJ output, where I=1..4, J=1..4
Example: So Shear-IJ, what units it has? lb/in? Also what is kick output? Thanks. Kristina.
Sorry about how it looks, when I paste it it shows good format but preview does not show good format.
F O R C E S A C T I N G O N S H E A R P A N E L E L E M E N T S (CSHEAR)
====== POINT 1 ====== ====== POINT 2 ====== ====== POINT 3 ====== ====== POINT 4 ======
ELEMENT F-FROM-4 F-FROM-2 F-FROM-1 F-FROM-3 F-FROM-2 F-FROM-4 F-FROM-3 F-FROM-1
ID KICK-1 SHEAR-12 KICK-2 SHEAR-23 KICK-3 SHEAR-34 KICK-4 SHEAR-41
0 40069 2.50181E+02 4.25804E+01 -1.47293E+02 2.94144E+00 1.22708E+02 2.62269E+01 -1.63647E+02 1.30414E+02
0.0 2.92114E+01 0.0 2.92114E+01 0.0 2.92114E+01 0.0 2.92114E+01





RE: CSHEAR Element Output
TTFN (ta ta for now)
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RE: CSHEAR Element Output
to be sure, either run a test case, or it should be in the manual
another day in paradise, or is paradise one day closer ?
RE: CSHEAR Element Output
Page 897, section 7.2 say "All items are element forces (or moments) unless otherwise indicated".
Page 913 shows CSHEAR O/P, only list all items, and Shear-IJ is real number magnitude (RM). That's why I confuse.
RE: CSHEAR Element Output
RE: CSHEAR Element Output
an example ..
take 1 CSHEAR element, say 2" square and 0.05" thk
surround it with RODs,
constrain 1 edge (2 nodes) to restrain rigid body motion,
load the opposite edge, in-plane, some load
then verify shear stress = element force/thk.
another day in paradise, or is paradise one day closer ?
RE: CSHEAR Element Output
I see this now:
F O R C E S A C T I N G O N S H E A R P A N E L E L E M E N T S (CSHEAR)
====== POINT 1 ====== ====== POINT 2 ====== ====== POINT 3 ====== ====== POINT 4 ======
ELEMENT F-FROM-4 F-FROM-2 F-FROM-1 F-FROM-3 F-FROM-2 F-FROM-4 F-FROM-3 F-FROM-1
ID KICK-1 SHEAR-12 KICK-2 SHEAR-23 KICK-3 SHEAR-34 KICK-4 SHEAR-41
0 5 -5.00000E-01 -5.00000E-01 5.00000E-01 5.00000E-01 -5.00000E-01 -5.00000E-01 5.00000E-01 5.00000E-01
0.0 -5.00000E-01 0.0 -5.00000E-01 0.0 -5.00000E-01 0.0 -5.00000E-01
Element is like below (corner nodes 1234, middle rod elements 1234, and CSHEAR 5):
---------3
4 ======= 3 --> 1 lbf
4[-------5-----]2
1 ======= 2
---------1
In first try I make 1.0" square element, then Shear-12 was 1.0.
Next I increase size to 2.0" same load and constraint, now Shear-12 is 0.5, so I think it is lb/in.
Shear-12 = (End Load 1 + End Load 2)/L where L=2.0" now.
Shear-12 = (0.5 + 0.5)/2 = 0.5 lb/in
I also check element max shear stress:
S T R E S S E S I N S H E A R P A N E L S ( C S H E A R )
ELEMENT MAX AVG SAFETY ELEMENT MAX AVG SAFETY
ID. SHEAR SHEAR MARGIN ID. SHEAR SHEAR MARGIN
5 3.125000E+01 -3.125000E+01
So shear flow using max shear = 31.25 psi*t, where t = 0.016"
q = 31.25*0.016 = 0.5 lb/in
But I don't understand the signs, can you help?
Also, I apply 1lbf at top right, but below is rod forces:
F O R C E S I N R O D E L E M E N T S ( C R O D )
ELEMENT AXIAL ELEMENT AXIAL
ID. FORCE TORQUE ID. FORCE TORQUE
1 0.0 0.0 2 -5.000000E-01 0.0
3 0.0 0.0 4 5.000000E-01 0.0
Why only 0.5lbf in right and left rods and no load in top rod? I understand no load in bottom rod pinned.
RE: CSHEAR Element Output
carefully read sign conventions in the NASTRAN manual, sometimes the +ve sense is determined by the node numbers, sometime by the node sequence, sometimes by the co-ord system.
rod forces ... draw a FBD ... how are you applying the load ? (1/2 to each corner ? then the rod is doing nothing)
the element between the constraints probably also (particularly if over-constrained)
the other two sides need to react load to preserve moment balance, considering the moment about the constraints from the load (yes?)
another day in paradise, or is paradise one day closer ?
RE: CSHEAR Element Output
I apply 1 Lbf at top edge. OK that is also clear now, nastran apply 0.5 lbf at each top node so no load in rod.
Yes, moment balance also I get, bottom left node 1.0lbf Down reaction, and bottom right node Up reaction.
Thank you very much.