6 Replies Latest reply on Feb 4, 2010 11:32 AM by Loic Ancian

    The reason that causes "Preconditioner_Fails_To_Factor"

    Albert Liu

      Dear Solidworks users:


      I have been trying to run a complex model using solidworks, however, my analysis collapsed in the process of "solving contact constraints" with the reason "Preconditioner_Fails_To_Factor". My question is what the type of error means and how to eliminate such error? Thank you very much!


      Sincerely Yours, Albert

        • Re: The reason that causes "Preconditioner_Fails_To_Factor"
          Loic Ancian

          Don't know... try to compute the case with the option "stabilize model" checked.

          You may have not properly constrained your model and no equilibrium can be found. With this option, you will be able to see what's wrong .

            • Re: The reason that causes "Preconditioner_Fails_To_Factor"
              Albert Liu

              Thank you so much, however, I am using "Mesh and Run" within the "Simulation" tab in Solidworks and could not find where I can set the "Stabilize Model" option. Can you show me the correct path to check that option? Thank you again in advance.


              - Albert

                • Re: The reason that causes "Preconditioner_Fails_To_Factor"
                  Brian Zias

                  Hi Albert,

                  I usually have seen this error when I have a rigid body mode.  Sounds like one of your no penetration sets might be slipping loose or a component is not contacted/constrained properly.  Right-click at the very top of your simulation study tree (where it says the study name) and there is a Properties...


                  Turn on the "Enable soft spring to stabilize model" option.  Then try re-running.  Make sure and mesh draft so you don't waste your timeuntil you know the model will work.  This should hopefully solve, and allow you to check the displacement plot. Make sure the displacement plot is set to automatic deformation scale in the plot Definition.


                  If that still fails, then turn your no penetrations into bonded, see if that works.  If it does, then turn them individually back to no-pen, running in between (like i said, use coarse draft mesh to start until this model works, then rerun high and fine).


                  Also, make sure the "large displacement" option is NOT selected in the study properties (the same dialog in which you enabled the soft spring).  This leads to convergence issues with no penetration sets it seems.




              • Re: The reason that causes "Preconditioner_Fails_To_Factor"

                If your study is saying "excessive displacements" you can figure out what is going on by choosing "soft springs" in the study options, or even better "use inertial relief".  This will give you an idea of what parts are not constrained.  Turn it off after you figure out what the problem is and fix it.  If you leave "inertial relief" on, it will not give you the real static analysis solution.  It is, however, VERY useful for finding fiddly little components you forgot were not touching anything.


                Good luck!



                • Re: The reason that causes "Preconditioner_Fails_To_Factor"
                  Loic Ancian


                  By "stabilize model" I meant "soft springs" in the study options, or "use inertial relief".

                  Because my sw is in french I didn't know how it was translated.


                  In this way you can figure out why your model has a large disp and fix it.