User Area > Advice
Typical warning message from LUSAS Solver text output file (*.OUT):
***WARNING*** ELEMENT P, NODE Q, VARIABLE
R HAS NEGATIVE PIVOT -0.1079E+10
Most common causes & links to solutions
If this occurs in a nonlinear analysis, we would recommend that you test your model on a linear analysis before setting non-linear & transient parameters since this will make it simpler to identify causes for failed analyses. There is a
basic checklist on the User Area which is applicable to linear static analyses.
The warning gives element numbers and these can be located in the model using
TreeView > Layers tab > Labels > (check) Element name (check) Label selected features only
and
Edit > Advanced selection
The most common cause of such a message is that there are insufficient
supports assigned to the model. It is necessary to ensure that
there exist supports that restrain the entire model from rigid body
movements. The model should not be free to translate or rotate
freely. More common
causes on a page of related warnings
Continued difficulties? Try
the pivot checklist
More on cause & theory links
More on negative
pivots
Use of the option in Solution Control "Continue solution if more than one negative pivot occurs" should be used with care, as it is likely to hide more fundamental analysis problems. It invokes the LUSAS option number 62.
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