cylindrical beam model solid

[ector]

hi guys, here I am again with some problem to solve...I just started working with cosmosworks, and as exercise I am trying to compare the results of a cylindrical isostatic beam model with how much I get from theory. as an arrow following the load I go well, but as a bending voltage we are not there. I have tried in different ways, but it never comes out the value "correct".
I send you the model, maybe I'm wrong (secure) a passage, so that you can kindly give me some tips.

Ettore

 

[ector]

hi guys, here I am again with some problem to solve...I just started working with cosmosworks, and as exercise I am trying to compare the results of a cylindrical isostatic beam model with how much I get from theory. as an arrow following the load I go well, but as a bending voltage we are not there. I have tried in different ways, but it never comes out the value "correct".
I send you the model, maybe I'm wrong (secure) a passage, so that you can kindly give me some tips.

Ettore

Is there no one who can give me at least some disappointments? ?

 

[RS4]

hi guys, here I am again with some problem to solve...I just started working with cosmosworks, and as exercise I am trying to compare the results of a cylindrical isostatic beam model with how much I get from theory. as an arrow following the load I go well, but as a bending voltage we are not there. I have tried in different ways, but it never comes out the value "correct".
I send you the model, maybe I'm wrong (secure) a passage, so that you can kindly give me some tips.

Ettore

hi ettore

but what kind of analysis maybe

make a pattern

you can post an iges

Hi.


♪

 

[ector]

the problem of constraints and deformation I solved it, in fact now with the applied load it deforms as it must. But now I do not understand how to interpret the myriad of results that returns... I explain better: in the solid beam to get the correct value of deformation I have to take the intense value of stress, in the shell instead not, among other things I do not find what best lends to the theoretical result... I send you some files of delucidazione... and also the model in iges and solids.

 

[RS4]

the problem of constraints and deformation I solved it, in fact now with the applied load it deforms as it must. But now I do not understand how to interpret the myriad of results that returns... I explain better: in the solid beam to get the correct value of deformation I have to take the intense value of stress, in the shell instead not, among other things I do not find what best lends to the theoretical result... I send you some files of delucidazione... and also the model in iges and solids.

Hello, ettt...

I ask you more material information, diameter, stud thickness or framed you have sides and more

Okay, let me know.

Hi.

♪

 

[ector]

Hello, ettt...

I ask you more material information, diameter, stud thickness or framed you have sides and more

Okay, let me know.

Hi.

♪

cylindrical hollow, of east 50 mm, thickness 5 mm, length 1000 mm, beams simply rested, isostatic.material steel alloy (e= 210000 mpa; density 7700 kg/m3)

thanks in advance

 

[RS4]

cylindrical hollow, of east 50 mm, thickness 5 mm, length 1000 mm, beams simply rested, isostatic.material steel alloy (e= 210000 mpa; density 7700 kg/m3)

thanks in advance

hi ettore excuse the delay

I used all the parameters from you indicated

analysis with catia v5

mesh tetraedrica of 15mm

type of bond isostaticType of load: g -9.81m/s2 lungo asse ztype of analysis
photos1 constraint_isostat_sforzi_la_von_mises
photos constraint_isostat_vectors_translation

in these days allowing you I will also post analytical values and we will compare them

I hope you've been helped

hello good work

♪

 

[ector]

Thank you very much for the courteous availability!I set a load in concentrated half-carry of 5000 n, and I noticed that the values, of course, change as they affect the mesh. I talk about voltage jumps in the above solid model, from 262 mpa for a medium mesh to 174 mpa for a thin mesh. the theoretical value should be172.5!I do not know if it is admissible as a range of tolerance. . .
a question, catia in your opinion is better as a fem program than cosmos? and above all, are there guides explaining the quite clear function?? ? with cosmos I am having results that sincerely I am not clear.. .

Thank you very much

 

[ballino]

Hello ettore81,
I looked at the model,
results hyperstatic 1 time

the put constraints are two hinges for which 4 gdv and
one of the two charge only half section.

a rod has only 3 gdl.
I recommend that you degrade one of the two constraints on support alone.

good work,
dancer

 

[RS4]

Thank you very much for the courteous availability!I set a load in concentrated half-carry of 5000 n, and I noticed that the values, of course, change as they affect the mesh. I talk about voltage jumps in the above solid model, from 262 mpa for a medium mesh to 174 mpa for a thin mesh. the theoretical value should be172.5!I do not know if it is admissible as a range of tolerance. . .
a question, catia in your opinion is better as a fem program than cosmos? and above all, are there guides explaining the quite clear function?? ? with cosmos I am having results that sincerely I am not clear.. .

Thank you very much

hi ettore

I did the analysis again

mesh tetraedrica of 15mm

type of histostatic bond

Type of load: linear load density -5000n long axis z to center beam

type of analysis
photos1 constraint_isostat_5000n_sforzi_alla_von_mises
photos constraint_isostat_5000n_vectors_translation

results

efforts_to_von_mises max 90.9mpacarriers_translation max 0.471mmI hope I understand you try to remake the analysis by setting the following mesh.

I can't answer you because I don't know cosmos.


Hello
Hi.

 

[ector]

Hello ettore81,
I looked at the model,
results hyperstatic 1 time

the put constraints are two hinges for which 4 gdv and
one of the two charge only half section.

a rod has only 3 gdl.
I recommend that you degrade one of the two constraints on support alone.

good work,
dancer

I did what I recommend, but the result does not change...cmq the values of the solid model and shell differ even if recently. the beam model is almost perfect.
a question, where could I find guides for cosmos?

 

[ector]

hi ettore

I did the analysis again

mesh tetraedrica of 15mm

type of histostatic bond

Type of load: linear load density -5000n long axis z to center beam

type of analysis
photos1 constraint_isostat_5000n_sforzi_alla_von_mises
photos constraint_isostat_5000n_vectors_translation

results

efforts_to_von_mises max 90.9mpacarriers_translation max 0.471mmI hope I understand you try to remake the analysis by setting the following mesh.

I can't answer you because I don't know cosmos.


Hello
Hi.

I'm trying to cuff out for a second and I'm telling you.

 

[luigi.paiano]

Excuse me but are those shell elements? I don't think they look tetrahedra. ..because if it is so the "errors" are absolutely normal

 

[luigi.paiano]

I recommend you to study the theory behind the finite elements.. is a passionate advice because, if you do it for work, you risk doing huge damage.
you can't simulate a bending beam with tetrahedri, you will get definitely wrong results except if you refine the mesh remarkably (the tetrahedron is a constant tension element and is definitely not used).
a shell element is completely different from a tetrahedric because it simulates the behavior of a plate.
then or use hexedral elements to 20 knots or real shell elements.
Even the constraints seem wrong. Why did you only bind those points in the section? And then that concentrated load? It is not as in the beam,the model is solid and a force concentrated from place to singularity and to huge efforts nearby that are not real. .