Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

Stationary study fails, but time-dependent study completes

Please login with a confirmed email address before reporting spam

When running a stationary study, I receive an error:

Feature: Stationary Solver Failed to find a solution. Singular matrix.

However, when running a time-dependent study, I do not receive any errors and the study finishes.

What could be causing the stationary study to fail in this situation? My model involves a solid block with wells and fractures inside. It couples Solid Mechanics and Darcy's Law with the Poroelasticity interface.

Thank you.


2 Replies Last Post Nov 10, 2022, 1:55 p.m. EST
Henrik Sönnerlind COMSOL Employee

Please login with a confirmed email address before reporting spam

Posted: 2 years ago Nov 10, 2022, 2:18 a.m. EST

Chances are large that you have too few constraints, so that there are possible rigid body modes. Then a dynamic analysis will run, since the inertial forces will ensure a force balance.

-------------------
Henrik Sönnerlind
COMSOL
Chances are large that you have too few constraints, so that there are possible rigid body modes. Then a dynamic analysis will run, since the inertial forces will ensure a force balance.

Please login with a confirmed email address before reporting spam

Posted: 2 years ago Nov 10, 2022, 1:55 p.m. EST

Thank you, Henrik Sonnerlind! I solved the issue. My matrix permeability was set to 0 m^2 and I solved it by making it a very small value instead, 1e-100.

Thank you for your response!

Thank you, Henrik Sonnerlind! I solved the issue. My matrix permeability was set to 0 m^2 and I solved it by making it a very small value instead, 1e-100. Thank you for your response!

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.