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ERROR at G.S.Analysis: Singularity detected...(pivot too small)... HELP


New member
So I'm running GSAnalysis on a mesh with 8 different surface parts joined by spot weld connections.
When computing the analysis I end up with this error:

Factorized matrix computation.
Singularity detected in rotation (pivot too small)
Possible reasons: missing restraint or connection specifications.
Display rotational vectors to diagnostic the problem.

I'm not sure how to solve this. If anyone has experienced this before please help me.

I did an analysis on a more simple model with 3 rectangular surfaces (2 spot welds) and it worked with no problems.
Then I removed one of the spot weld connections and I got the same error as mentioned.

I guess this means there's a part not connected to the others in the original model and that's why I get this error.
I just can't find this part and would appreciate any tips on how to do it.


New member

As said in the message the restrains are not complete.
Try to give restrains through "user defined restrains" tool.
There will be 6 DOF in each ite. depending on the model, sometimes restraining rotational degrees of freedom are restrained by defining the translational degrees of freedom
and conditions are not needed. In the user defined restrains window, 6 options were available. first three check boxes are translational DOF with X, y, Z in a manner. other three are X, Y, Z's rotational DOF restrains.

As we couldn't understand the plan / model from your description, please try it with each item seperatly as well as combined with one another.

Hope this will help.


New member

The part or the product is not fully constrained. You have to add the missing specifications.

To find the missing specifications you can generate deformations images (Visualizing Deformations) or displacements image (Visualizing Displacements) and then animate the generated image (Animating Images).

You can use the User defined constraints tool for every rotational and translational DOF.