COMSOL: Newton's Iteration reached - Stress testing sensor

Click For Summary
The discussion revolves around a sensor model in COMSOL experiencing convergence issues during analysis. Attempts to resolve the problem included increasing iterations, refining the mesh, and conducting parametric studies, but the error persists, particularly with a MUMPS out-of-core warning. The model uses a hyperelastic material for the block beneath the sensors, which complicates convergence when nonlinearity is enabled. Recommendations include avoiding contact definitions until the analysis stabilizes and possibly adjusting the hyperelastic model or load conditions. The source of material constants for the hyperelastic model is also questioned for further troubleshooting.
uppityd
Messages
5
Reaction score
0
It is a sensor with a fixed surface and a prescribed displacement on the opposite

To remove this message error,

I have tried to
  1. Increase iterations
  2. Refined mesh
  3. Applied parametric studies
  4. And some other ideas from forums
However it still cannot be solved

It also has a warning of MUMPS out of core
 

Attachments

  • sensor.PNG
    sensor.PNG
    16.9 KB · Views: 149
Engineering news on Phys.org
How are these parts connected ? Do you use contact in this analysis ?
 
FEAnalyst said:
How are these parts connected ? Do you use contact in this analysis ?
They are joined using form union, i would like to put contact between the sensors together in later.
 
uppityd said:
They are joined using form union, i would like to put contact between the sensors together in later.
Right, it’s better to avoid contact until the analysis converges with Form Union. Especially that contact in Comsol is very susceptible to convergence difficulties.

Contact is not used here but there are other forma of nonlinearity in this model, right ? Do you have the geometric nonlinearity enabled ? What about the material model - which one do you use ?
 
FEAnalyst said:
Right, it’s better to avoid contact until the analysis converges with Form Union. Especially that contact in Comsol is very susceptible to convergence difficulties.

Contact is not used here but there are other forma of nonlinearity in this model, right ? Do you have the geometric nonlinearity enabled ? What about the material model - which one do you use ?
Sorry, I should have specified a lot better.

The main reason is that the block underneath the spherical disks is a hyperelastic material. If the whole model were to be set as a linear material then it converges, however when set as a hyperelastic material, the block underneath, then it does not.Non linearity is enabled.
 
The hyperelastic material might be unstable in a given strain range. Try with a lower load and maybe a different hyperelastic model. What is the source of data for material constants in this case ?
 

Thread 'UV filter for home central heating?'

Had my central air system checked when it sortta wasn't working. I guess I hadn't replaced the filter. Guy suggested I might want to get a UV filter accessory. He said it would "kill bugs and particulates". I know UV can kill the former, not sure how he thinks it's gonna murder the latter. Now I'm finding out there's more than one type of UV filter: one for the air flow and one for the coil. He was suggesting we might get one for the air flow, but now we'll have to change the bulb...
View full post »

Similar threads

Newton's Sphere Theorem Argument is false.
  • · Replies 9 ·
Replies
9
Views
7K
Can Old Handouts Effectively Prepare You for Physics Tests?
  • · Replies 11 ·
Replies
11
Views
4K
Is Gravity Caused by the Motion of Particles in the Fabric of Space?
  • · Replies 463 ·
16
Replies
463
Views
72K
A suggestion for dolphin communication.
  • · Replies 6 ·
Replies
6
Views
6K