mamma_samu
Guest
Hi, how can I simulate longitudinal reinforcements on a patran cylinder for a buckling analysis? thanks:biggrin:
Lorenzo_Z
Guest
the description of the problem is a bit generic, I can tell you that you can insert beam elements connected with the mesh of the cylinder, I recommend the equivalence of the knots before launching the analysis, in such a way as to have the connected structure.
Let me know.
Lorenzo
Let me know.
Lorenzo
mamma_samu
Guest
hello lorenzo and thanks for the answer. Then I will explain to you in detail the problems that have arisen. then I first started by simulating the buckling of a normal cylinder and since there was no problem, the simulation as a result gave me the phenomenon of landing. I then proceeded by inserting parallel reinforcements to the axis of the cylinder and to do this I created 4 curves on the surface to which I assigned the beam property while to the surface of the cylinder, which I created starting from a circle and extruding, the shell property. I made mesh automatically and I did the equivalence. but the results of the analysis are not good because it is as if the cylinder did not deform and also in another simulation of which I do not remember the difference from the previous one was as if only one reinforcement had been inserted instead of 4. I also tried to draw geometry in 3d but tells me that some elements are not associated with any property and does not make me proceed. I am no more than inventing myself....
Lorenzo_Z
Guest
If you want to pass me the .db I'll take a look at him... .
mamma_samu
Guest
Here it is, I have made some changes in extremis, tell me what you think, thanks for patience.
mamma_samu
Guest
ah and since there are I would need to know how to perform a post-buckling analysis.
Onda
Guest
The model is badly bound.
currently turning the analysis you have this error (f06):
0 g r i d i n t i n g u l a r i t y t a b l i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t
0 point type failed stiffness old uset new uset
id direction exclusive union union
5000 g 1 0.00e+00 b f sb s
5000 g 2 0.00e+00 b f sb s
means that the 5000 knot is missing in constraints in 1 and 2.
then your rbe also takes the knots below the edge of the shell that I doubt is not exactly what I wanted to do.
Maybe the easiest way to make a rbe2 connected from 1 to 3. then bind only the 5000 knot from 1 to 2, remember to delete the second row of knots in the beard.
I said this, the model makes a couple of buckling deformities that seem consistent to me.
other note, shells have the aspect ratio in the wrong direction. Keep in mind that you should keep at least 5 shells in the buckling wave.
If you see the image below there are no.
to simulate a compression cylinder the shells should be with the extension arranged in the opposite direction.
the shape of the deformed seems correct to me, with the four waves that are generated in the four quadrants defined by the beams.
currently turning the analysis you have this error (f06):
0 g r i d i n t i n g u l a r i t y t a b l i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t i t
0 point type failed stiffness old uset new uset
id direction exclusive union union
5000 g 1 0.00e+00 b f sb s
5000 g 2 0.00e+00 b f sb s
means that the 5000 knot is missing in constraints in 1 and 2.
then your rbe also takes the knots below the edge of the shell that I doubt is not exactly what I wanted to do.
Maybe the easiest way to make a rbe2 connected from 1 to 3. then bind only the 5000 knot from 1 to 2, remember to delete the second row of knots in the beard.
I said this, the model makes a couple of buckling deformities that seem consistent to me.
other note, shells have the aspect ratio in the wrong direction. Keep in mind that you should keep at least 5 shells in the buckling wave.
If you see the image below there are no.
to simulate a compression cylinder the shells should be with the extension arranged in the opposite direction.
the shape of the deformed seems correct to me, with the four waves that are generated in the four quadrants defined by the beams.
mamma_samu
Guest
Thank you very much for the tips. I still needed a couple of aids, in theory I modified the herb3 so as not to take the knots below and I bound the 5000 knot in fact in f06 does not seem to give me the error anymore. I can neither change the orientation of the shell nor the aspect ratio.. .
I attach the new file
I attach the new file
Onda
Guest
utilities>fem elements>break elements with split on logest edge option
then do the same for bars in the same menu
so do equivalence all.
Regarding the rp should be transformed into rbe2 from 1 to 3 on the central node.
the 5000 knot must be bound on 1,2,4,5,6
then the elastic module of the material multiplies it for 7000 for the properties of aluminum
and this result
then do the same for bars in the same menu
so do equivalence all.
Regarding the rp should be transformed into rbe2 from 1 to 3 on the central node.
the 5000 knot must be bound on 1,2,4,5,6
then the elastic module of the material multiplies it for 7000 for the properties of aluminum
and this result
mamma_samu
Guest
hello and excuse the trouble again....to do buckling analysis how do I create graphs? But I don't know if that's correct.
thanks for the help
thanks for the help
Onda
Guest
What kind of chart do you want to do? It's not that you're very clear. You didn't even tell us if you solved your previous problems. the forum serves not only to ask, but also to clarify to those who read the solutions to which they arrived. so once a problem is closed, a summary message is definitely appreciated by the community. And maybe putting things down by writing can do well to you too.
wave
wave
mamma_samu
Guest
I apologize to everyone if I didn't fully comply with the forum regulations. then regarding buckling analysis thanks to wave tips I managed to get the expected results. basically the problem I had was to fail to make sure that reinforcements were seen as such. I solved by making a mesh 2d on the surface of the cylinder to which I had associated the shell property and then made a mesh 1d on reinforcements with beam propitiage. In this way I solved. I practically didn't do the mesh on backup.
Now I have to do a post buckling analysis. not knowing where to start I found a msc tutorial in which they used a static nonlinear analysis. I tried a little to adapt it to my specific case but not knowing even what I had to get I can not understand whether it makes sense or not what I did. as soon as I find the program file the place.
thanks in advance
Now I have to do a post buckling analysis. not knowing where to start I found a msc tutorial in which they used a static nonlinear analysis. I tried a little to adapt it to my specific case but not knowing even what I had to get I can not understand whether it makes sense or not what I did. as soon as I find the program file the place.
thanks in advance
mamma_samu
Guest
Good morning to all, I find myself here because I need your help again. then this time I will try to be clear and apologize if in previous posts I have not been.
then they are still struggling with simulating the buckling phenomenon of a longitudinally reinforced cylinder.
My current problems are 2:
- I must recreate the results found in the bibliography; to do this I have to recreate the geometry of the test. This consists of a series of reinforced cylinders of which I have dimensions and material. These cylinders are subject to a "pure bending" that I don't know how to simulate. I don't even know if the reinforcements are correct because they don't always give me equal results. I set the analysis by always putting an axial load to see if at least the resulting buckling type was consistent.
a second problem has arisen here.. .
- a sample deformed seems to come right while another one doesn't.
I don't know what to do anymore.
I attach a file to make your ideas clearer. I hope I've been clear enough.
Thank you very much
then they are still struggling with simulating the buckling phenomenon of a longitudinally reinforced cylinder.
My current problems are 2:
- I must recreate the results found in the bibliography; to do this I have to recreate the geometry of the test. This consists of a series of reinforced cylinders of which I have dimensions and material. These cylinders are subject to a "pure bending" that I don't know how to simulate. I don't even know if the reinforcements are correct because they don't always give me equal results. I set the analysis by always putting an axial load to see if at least the resulting buckling type was consistent.
a second problem has arisen here.. .
- a sample deformed seems to come right while another one doesn't.
I don't know what to do anymore.
I attach a file to make your ideas clearer. I hope I've been clear enough.
Thank you very much
mamma_samu
Guest
Good morning, today has arisen a new problem that I cannot find a solution. I modified the reinforcements by inserting the correct offsets so that the reinforcements were put outside the surface. The problem is that by launching the buckling analysis, it doesn't give me autovalues anymore, but only a deformed one. How come?
Thank you.
Thank you.