Stability Criteria
GHS provides a very flexible means of representing stability criteria.
Aspects of stability which can be measured automatically are:
- Angle interval
- Area under the righting arm curve
- Residual area between the heeling and righting arm curves
- Ratio of area under the righting arm curve to area under the heeling arm
curve
- Ratio of residual area before to residual area after equilibrium
- Ratio of righting arm to heeling arm at a particular angle
- Maximum of absolute righting arm relative to its value at equilibrium
- GM upright or at equilibrium heel
Most of these measures refer to an interval between angles. Such angles can
be given as literal values, or symbolically as the angles at certain points
such as:
- angle of equilibrium
- angle of downflooding
- angle of maximum righting arm
- angle of vanishing righting arm (second intercept)
- angle of deck edge or margin line immersion
Any combination of these aspects of stability can be combined to form a
composite stability criterion. Virtually all of the world's standard
stability criteria can be modeled in this manner. In addition, the user is
free to experiment with modifications of, or additions to, the standard
criteria.
After a stability criterion has been specified, GHS will evaluate any loading
condition against the criterion, showing how it fared under each aspect of the
criterion.
GHS will also generate curves of maximum VCG (KG) as a function of
displacement and initial trim for a given criterion.
All of the foregoing stability analysis can be carried out with or without
flooding due to damage, with or without heeling moment due to wind (or other
cause) and with or without various wave profiles.
Copyright (C) 1997
Creative Systems, Inc.