ssc-367 - Ship Structure Committee

the set of extreme conditions, and thus, he/she is unable to create
alternate conditions to.check for greater response.
The design engineer may request a range of extreme conditions, such
as: the maximum height wave with a period of 9 see, the maximum
height wave with a period of 10 see, etc. The increased number of
conditions increases the number of analyses required, but allows the
design engineer to confirm which conditions produce the extreme
responses.
The maximum wave height method is best used when
highly nonlinear and the spectral analysis method
appropriate.
the response is
is therefore not
B.3.2 Wave Spectrum Method
A full probabilistic analysis involves calculating responses to the
entire suite of possible environmental conditions. Statistical
analysis of these responses is then performed In order to predict a
suitable extreme for each response. This requires far fewer
assumptions on the part of those who supply environmental criteria,
but a much more extensive set of environmental data.
/ -.
With the wave spectrum method, a set of wave spectra are provided by
oceanographers or meteorologists. The RAOS for the response of
interest are squared and multiplied by the wave spectrum. A wave
spectrum is assumed to represent a Gaussian random distribution.
Since the response spectrum is created by a linear multiplication,
the response spectrum also represents a Gaussian random
distribution.
be calculated
maximum, etc. wave heights.
The significant response, maximum response, etc. can
using the equations for calculating the significant,
The equations
response:
for maximum wave height are summarized here in terms of
B-16