Learning Forum

[thabtisalma]

hi 

i have problem in the contact 

any help please 

[peteroznewman]

Hi Salma,

I opened your archive in ANSYS 18.2. Is this the version you are using?

Here is your model:

You have 500 N up and 500 N down on the same face, so that cancels out and is zero.
You have 0 N on the side face.  Please explain what you want to simulate.

 

[thabtisalma]

i want to simulate the assembly loads 

[thabtisalma]

the force B = 6000N 

[peteroznewman]

Which part is being assembled?  The top block?  Why is Force 2 and 3 up and down? When you push the top block sideways with 6000 N, do you want the pin bonded to the top block?

[peteroznewman]

I see the 6000 N now. When I unsuppress the first contact bonding the pin to the hole in the top block, you get a solution.

Is this what you want?

[thabtisalma]

ok i want to apply a loads to simulate the assembly between the two blocks ; and i delate the contact between block  and the pin, 

the pin is fixed with the gris block , 

 

[thabtisalma]

when i delate the contact ,  i face problem in the strain 

[thabtisalma]

check the contact please 

[peteroznewman]

Quelle est la force latérale pour? Décrivez le processus d'assemblage plus en détail. Essayez d'écrire en français et laissez Google fournir la traduction en anglais.

What is the side force for?  Describe the assembly process in more detail. Try writing in French and let Google provide the English translation.

 

[thabtisalma]

the erreur messege is 

The solver could not obtain convergent results for the nonlinear problem as constrained. Please refer to the Troubleshooting section of Help for more information. 

 

The non-converged resolution (identified as sub-increment 999999) is an output for the debug operations of the analysis. Results should not be used for any other purpose at this time. 

The state of the contact has been subject to abrupt variation. Check the results carefully and look for a possible separation of the contacts. 

[peteroznewman]

Sans le premier contact, il n'y a pas d'équilibre statique que le solveur trouvera. La force latérale pousse le bloc supérieur hors du bloc inférieur.

Without the first contact, there is no static equilibrium that the solver will find. The side force will push the top block off the bottom block.

[thabtisalma]

I try to simulate a clamping force between the block in red and the pinch I disable the contact between them, this force is presented by the two forces C and D 

sorry my english isn't very good 

[thabtisalma]

so how to solve it ? 

[peteroznewman]

Je comprends que vous voulez une force de serrage de 500 N vers le bas sur le bloc supérieur. Ensuite, je vais supprimer "C" parce que ce n'est pas en baisse. La goupille dans le bloc supérieur est-elle ajustée ou est-ce un ajustement serré? Si je suppose que c'est un ajustement de dégagement, alors vous ne voulez pas un contact collé, vous voulez un contact de frottement. Qu'en est-il de l'ajustement entre la broche et le trou dans le bloc inférieur? Interférence ou autorisation?

Désolé, je ne connais que quelques mots en français mais Google peut traduire pour moi!

 

I understand you want a clamping force of 500 N downward on the top block. Then I will suppress "C" because that is up not down.  Is the pin in the top block a clearance fit or is it a press fit?  If I assume it is a clearance fit, then you don't want a bonded contact, you want a frictional contact.  What about the fit between the pin and the hole in the bottom block?  Interference or clearance?

Sorry, I only know a few words in French but Google can translate for me!

[peteroznewman]

Lorsque deux blocs partagent une broche, la broche doit être la cible et les blocs doivent être le côté contact de la paire. Vous pouvez choisir les deux et inverser les définitions.

When two blocks share a pin, the pin should be the Target and the blocks should be the contact side of the pair. You can pick both these and Flip the definitions.

[thabtisalma]

there is no contact between the top block ant the pic ( i desable it ) 

and there is a frictional contact betwen the two blocks 

the bottom block and the pin are fxed 

[peteroznewman]

Here is an ANSYS 18.2 archive that solves.

[thabtisalma]

 thank you  so much 

 

[thabtisalma]

i just want to undrestand  why you added the friction to be the upper block and the pin, already we applied a load 

[peteroznewman]

La broche aurait pu être un contact sans frottement ou frottement. Le résultat serait presque identique dans les deux cas. La charge est complètement séparée du contact entre la goupille et le bloc.

Si vous avez une force descendante assez importante, il est possible que la force latérale soit supportée par le frottement entre les blocs seuls sans aucune goupille, mais vous auriez besoin d'une force de descente supérieure à 6000 / 0,15 pour supporter la charge latérale.

The pin could have been frictionless or frictional contact. The result would be almost identical either way.  The load is completely separate from the contact between the pin and the block.

If you have a large enough down force, it is possible for the side force to be supported by the friction between the blocks alone without any pin, but you would require a down force greater than 6000/0.15 to support the side load.

[RChandran]

Can I get your email?

[peteroznewman]

@RChandran,    Whose email;  mine or thabtisalma's?