too many atempts

[navigator30]

I'm having a big problem with the convergence of my contact model. Every calculation is aborted with the note "too many attepts", what can I change to either to let more attempts be made or ....well I don't know. What can I do????

 

[corus]

Use contact controls. Usually too many attempts means there's something else wrong with the model though.

corus

 

[navigator30]

I have an assembly of three flat parts that are loaded on top of the thirt part. Additionally I want to move that part for 2 mm, thats not too much as I think but after 0.7mm I get the too many attempts message

 

[turantug]

i think the model is out of the sticking region (i assumed that you are using coulomb friction) and it is making a rigid body motion. add a linear spring and track the force in the spring, it will help to converge the problem. and if needed change the friction force.

 

[corus]

I'd look at the solution you get at the end of 0.7mm movement to see if you can see what's wrong. Otherwise you can use the *controls and use either analysis=discontinuous or set the time incrementation parameter so you get more iterations.

corus

 

[navigator30]

it's a bit late, but thanx for the answers guys!
I'm gonna try - didn't have time yet to do so.

navigator

 

[Newuser2006]

hallo all,ihave also the same error message'Too many attempts for this increment'and iam doing a simple heat transfer analysis.Anyone can help me or what may be the cause?

 

[corus]

Newuser,
Presumably you're running a severe transient analysis and/or have radiation to give such an error. Check your initial temperatures or boundary conditions and/or your units for stefan boltzmann's thingymajig.

corus

 

[Newuser2006]

thanks corus,but iam doing a heat transfer without any radiation,the simulations lasts for 60 seconds,all was working ok and i got results,but when i tried to refine the mesh(i have changed the global seed size) i started to get the error message and when i returned the global seed size to intial one it didnt work either.so what do you think?

 

[corus]

Regardless of the time of the whole simulation if you have a severe change in temperature from some initial condition then you can get instability in the solution. Nomrally this instabibility disappears after a short period and can usually be ignored if it happens in the initial stages of the transient. Refining the mesh near the face/edge/point where the major changes in temperature occur should increase stability, not make it worse. Therefore the answer is, in short, I don't know.

corus