GHS BULLETIN
HSC Heeling Moment
In order to find a heeling moment such that the residual area ratio from an
initial "roll" angle to RA0 is unity, the HSCmmt macro from the MAXHMMT
library can be used. This library is distributed with the MAXHMMT wizard.
However the HSCmmt macro can be executed independently of the wizard.
Two parameters are required:
1) The "roll" angle. This is the angle offset from zero where the area
integration begins. It should be a positive number for starboard-side heeling.
For example, if the given roll angle is 15, the curves will start at -15 and
proceed in the positive direction. If the given roll angle is negative, port-
side heeling will take place.
2) The initial heeling moment. This is an estimate of the heeling moment and
should not be so large that a capsize results. It can be positive or negative
regardless of the heel direction, since it will be adjusted as needed.
After finding the HMMT required to make the area ratio unity, the HSCmmt macro
produces a righting-arm curve to verify its finding.
Since the HSCmmt macro makes use of LIMIT commands, it will nullify any
existing LIMITs. Therefore the user must take care to define or redefine
LIMITs after using the HSCmmt macro.
Below is an example run using the FV.GF geometry file.
RUN MAXHMMT.LIB /CALL
READ FV.GF
DEPTH 5
VCG 8
SOLVE WEIGHT LCG
UNITS MT
REPORT
.HSCMMT 15, 100 '%1 - initial (roll) angle, %2 - initial hmmt
PRINT PREVIEW
REPORT OFF
END
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Creative Systems, Inc.