ssc-367 - Ship Structure Committee

Significant response, (DA):
R5 = 4.00*(mO)~
Maximum response in 1000 cycles, (DA):
R1/looo =
7.43*(mO)~ = 1.86*Rs
Maximum response is t hours, (DA):
R max
= 2*[2*mo*ln(3600*t/Tz)]$
where m. is the area under the response
spectrum,
Tz is the zero-up-crossing period of
from the equation,
the response as found
Tz = 2~*(mo/m2)4, and
m2
is the second radial frequency moment of
the response spectrum.
B.4 OPERATIONAL RESPONSE
In order to determine the normal day-to-day motions and stresses to
assess motion related downtime and fatigue damage, the distribution
of wave heights versus wave periods are considered. A wave scatter
diagram condenses and summarizes wave height and wave period
statistics. It is a two-parameter probability density function.
Typically a wave scatter diagram is presented as a grid of boxes,
with one axis of the grid being average zero-up-crossing periods and
the other axis being significant wave heights. Within the boxes of
the wave scatter diagram are numbers which represent the percentage
of the sea records having the corresponding characteristics of Hs and
Tz see Figure A-2.
B-17