Learning Forum

[mart9203]

Hi

My simulation won't even start. And Solver output isn't much help.

Please someone tell me what's happening!

 

 

Here aer some snippets from the Solver Output:

 *** ERROR ***                           CP =     153.219   TIME= 14:44:57
 The preconditioned conjugate gradient solver failed with an error code 
 of 1.  Please check for an insufficiently constrained model.           
 Switching to the sparse direct solver may allow this nonlinear         
 analysis to continue beyond this point.

 *** NOTE ***                            CP =      35.625   TIME= 14:43:13
 Max.  Initial penetration 0 was detected between contact element 112650
 and target element 112721.

 *** NOTE ***                            CP =      35.625   TIME= 14:43:13
 Max.  Initial penetration 0.475991245 was detected between contact     
 element 112178 and target element 111687.

[Wenlong]

Hi,

As the error message stated, your model is probably not sufficiently constrained, which means rigid body motion can happen. Here is what you can do to debug.

In Workbench, duplicate your Static Structural Analysis, and then right-click on the duplicated system--> Replace with --> Modal analysis. 

In the new Modal analysis system, run a modal analysis (don't change any boundary conditions). If there are 0 natural frequencies, it means your model has rigid body motion you need to constrain. You can plot the deformation to see what are the rigid body motions. 

Here is a tutorial about how to do a modal analysis: https://www.youtube.com/watch?v=uwim3BdINcs

Please let me know if it helps. 

Regards,

Wenlong

 

 

[Sai Deogekar]

Hi,

Can you share what boundary conditions are applied? The error message says the model may not be constrained sufficiently to prevent rigid body motions. Another thing you can try is using the Direct Solver. Go to Analysis Settings-->Solver Controls-->Solver Type--> Direct.

Here is another post which deals with a similar error:

/forum/forums/topic/preconditioned-conjugate-gradient-solver-error-level-1/

 

Hope this helps,

Sai