|
OCTOPUS can calculate so-called 'primary' responses, 'user-defined' responses and 'combined' responses.
The ship-specific results are stored in a binary rao-file. This file is used to calculate response statistics in waves.
Primary responses
Primary responses are always required in OCTOPUS. Primary responses can be obtained in two ways:
If there is an interface with a loading computer, the primary responses are calculated by OCTOPUS using the information
in the hydrodynamic database (CHDB-file) in combination with the mass distribution obtained from the loading computer.
This is the most accurate method since no assumption or approximation is made regarding the loading condition.
If there is no interface with a loading computer, OCTOPUS can use a pre-calculated set of transfer functions. In that
case, all these transfer functions are considered as 'primary responses'. These transfer functions are stored on the rao-file.
Typical primary responses are:
- Motions of the motion reference point (surge, sway, heave, roll, pitch, yaw)
- Relative motions in disturbed waves. If the hydrodynamics are calculated using a 3D-panel program, then OCTOPUS will take into account radiation and diffraction effects
- Pressures
- Shear forces and bending moments
User-defined responses
Absolute and relative motions, velocities and accelerations in user-defined points on the ship are defined as 'user-defined'
responses. User-defined responses are derived from the primary motion responses by taking single and double time-derivates.
The user-defined responses are added to the same binary rao-database of primary responses.
Combined responses
Combined responses in OCTOPUS are responses which are a linear combination of 'primary' and/or 'user-defined' responses.
Using this feature you can define any kind of response, which can be expressed as a linear combination of other responses.
Please note that all the phase information is maintained.
|