User Area > Advice
Typical error message found in the LUSAS Solver text output file (*.OUT):
***ERROR***
PIVOT ON LEADING DIAGONAL IS ZERO. MATRIX IS SINGULAR. IS THERE A RESTRAINT AT
NODAL POINT NUMBER X FOR NODAL VARIABLE NUMBER Y
Typical causes of this message 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.
- Shear area or other stiffnesses set to zero. Check your geometric attributes for stiffnesses which are zero. In general, eccentricity is the only stiffness parameter where a zero should be specified.
The error 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
More common
causes on a page of related warnings
Continued difficulties? Try
the pivot checklist
More on zero
pivots
|
