User Area > Advice
Typical warning message from LUSAS Solver text output file (*.OUT):
***WARNING*** CARE SHOULD BE TAKEN WHEN ACTIVATING AND DEACTIVATING ELEMENTS WITH GEOMETRIC NONLINEARITY PARTICULARLY WHEN LARGE DISPLACEMENTS ARE EXPECTED (OVERL6 PROCESSOR)
Most common causes & links to solutions
This is a warning message to inform the user that care should be taken when applying birth and death in a geometrically nonlinear analysis as deactivated elements will deform with a reduced stiffness in a stress and strain free state until activated.
Although the deactivated elements deform to keep the continuity in
the structure, they have no stress stiffening effects in them due to
the zero stress in them.
Large structural displacements may lead to large deformations of the deactivated mesh. This should be considered, and if the effect is significant, then the deactivated mesh may need to be controlled prior to activation. It may be necessary to apply prescribed displacements to deactivated elements in order to attain a required configuration for activation.
If necessary deactivated elements can be temporarily supported and
then released before activation by assigning free supports to them
at the right load cases.
For further information see:
Help > Help Topics >
Contents > Solver Reference
Manual > 3 LUSAS Data Input > Activate/Deactivate Elements
> Notes
|
