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Typical warning message found in the LUSAS Solver text output (*.OUT) file:

***WARNING*** UNABLE TO FIND VALID CONTACT SEGMENT FOR NODE P ON SURFACE Q CONTACTING WITH SURFACE R (SFSSEG PROCESSOR)


Most common causes & links to solutions 

This message warns that contact has not been established for the referenced node P.  Note that the referenced surface numbers are not geometry surface numbers in Modeller, but contact surface numbers used by Solver and as referenced in the Datafile and Output files.

A common reason for this warning is if the Master assignments and the Slave assignments are not pointing toward one another.  If you visualise both the Master assignments and the Slave assignments for a given slideline attribute you will see red arrows displayed. For slidelines to work correctly, these arrows for the two assignment categories should be pointing toward one another.  To see these visualisations, right-click on the slideline attribute and click on Visualise Master Assignments and then repeat for Visualise Slave Assignments.  

To reverse the directions of the arrows in a shell model, the normal direction for the relevant surface can be reversed. To do this, select the surface that has the slideline assignment with the normal direction that needs to be changed and go to:

Geometry > Surface > Reverse

Please also see the example "Contact Analysis of a Lug" available via:

Help > Help Topics > Contents > Examples Manual

Advice on slideline convergence problems 


More on cause & theory links

More about initial slideline penetration


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