# zone geometry-tolerance command

Syntax

zone geometry-tolerance f

This command defines the tolerance before an illegal geometry error happens in response to zone deformation. The user input f is the minimum ratio of the volume of a tetrahedral subzone to the zone volume. FLAC3D signals an illegal geometry error if that ratio is less than f for any tetrahedral subzone in the model. The default value is 0.0.

Note: Be aware that zone geometry is checked only every 10 steps in large-strain model. So, if the tolerance is set too close to zero, an error may be signalled elsewhere in the calculation before exiting at the selected ratio. Also note that the typical minimum subzone volumes are 0.2 of the full zone volume. So the maximum value selected for the ratio should be less than 0.2 to avoid premature termination of cycling.