## General Mechanical

#### Error: An internal solution magnitude limit was exceeded

• Nguyen Van Toan
Subscriber

Hello everyone,

I'm simulating deformation of a rod fixed by both ends. The loads are thermal and gravity. The material is nonlinear. There is no contact surface but I got the message as shown below. How can I solve it?

Thank you so much !

• peteroznewman
Subscriber
You have not provided enough information to determine why there is an excessive deformation.
• Nguyen Van Toan
Subscriber

• Nguyen Van Toan
Subscriber
@peteroznewman
I am sorry. There are some more details:
Geometry : Diameter of 2mm; length of 100mm.
Zero thermal expansion at 20 Celcius.
Plastic stress-strain, thermal load and coefficient of thermal expansion are shown in the figure below.
Thank you so much!

• Erik Kostson
Ansys Employee
Hi

Can you do the following:

Use linear material, and no large deflections, and only gravity (no thermal loads) and see if that runs.
Same as 2., but add large deflections.
Let us know the outcome of this and we will give some more feedback.

Thank you

Erik
• Nguyen Van Toan
Subscriber
@ekostson
Yes. I have peformed all cases you told me. For cases 1,2,3 they normaly worked. Only something wrong for last case as I asked you before.
• Erik Kostson
Ansys Employee
Thanks for that - so do the following now.

Same as 4 so use all loads (thermal+structural), but use linear material (no plasticity) and no large deflections.
Same as above but add large deflections (keep linear material).

Try that and let me know how it goes

Erik
• Erik Kostson
Ansys Employee
Did this example with some info from your post:

Have 2 steps, one gravity, and the second one, gravity + thermal load.

As I told you in a previous post we do get some buckling/instability and plasticity so that is why it is tricky to solve.

So use the following settings for the tricky 2nd step and that does it:

All the best

Erik
• Nguyen Van Toan
Subscriber
@ekostson
I will do that with your guidance. Thank you so much again.
• Erik Kostson
Ansys Employee
OK all the best