Learning Forum

[tahm]

I am getting this error message. How to resolve?

The solver engine was unable to converge on a solution for the nonlinear problem as constrained.  Please see the Troubleshooting section of the Help System for more information.

[Keyur Kanade]

As ANSYS Staff, we can not download attachments. Please insert images using insert image functionality. 

[tahm]

Here are some screenshots

[tahm]

I was doing a 2D plane strain analysis of soil element

[peteroznewman]

Increase the Initial and Minimum Substeps to 100.

Insert a command object

NEQIT,50

This will tell the solver to keep going for 50 iterations instead of doing a bisection or stopping after 26 iterations.

[tahm]

Still I am getting the error

[peteroznewman]

You have to improve the element shape where the solver is unable to obtain a force equilibrium and fails to converge.

You can find out where that is by typing a 4 in the field called Newton-Raphson Residuals under the Solution Information Folder.  Take out the NEQIT command. Solve. When if fails to converge, you will have 4 plots under the Solution Information folder. The plot is the Newton-Raphson Force Residual plot. The Maximum value on this plot is where you need better elements.

I already know that it will be in the interior corner.  If you put a small radius in that corner instead of a sharp interior corner, that will help it converge.