ABAQUS Keywords Reference Manual  


22. W, X, Y, Z

*WAVE
Define gravity waves for use in immersed structure calculations.

This option is used to define gravity waves for use in applying loads.

Product: ABAQUS/Aqua  

Type: Model data

Level: Model  

Reference:

Optional parameters:

INPUT

Set this parameter equal to the name of the alternate input file containing the data lines for this option. See “Input syntax rules,” Section 1.2.1 of the ABAQUS Analysis User's Manual, for the syntax of such file names. If this parameter is omitted, it is assumed that the data follow the keyword line.

TYPE

Set TYPE=STOKES (default) to use Stokes fifth-order wave theory.

Set TYPE=AIRY to use Airy (linearized) wave theory.

Set TYPE=GRIDDED to use gridded data to define the fluid particle velocities, accelerations, free surface elevation, and dynamic pressure.

Set TYPE=USER to use user subroutine UWAVE to define the fluid particle velocities, accelerations, free surface elevation, and dynamic pressure and to specify when to update the intermediate configuration for stochastic analysis.

Optional parameter for TYPE=AIRY: 

WAVE PERIOD

Include this parameter to indicate that the second field in the data line specifies the wave period, . If this parameter is omitted, the second field in the data line specifies the wavelength, .

Required parameter for TYPE=GRIDDED: 

DATA FILE

Set this parameter equal to the name of the file containing the gridded data. The file must be a sequential, binary-format file containing records in the format described in “ABAQUS/Aqua analysis,” Section 6.10.1 of the ABAQUS Analysis User's Manual.

Optional parameters for TYPE=GRIDDED: 

MINIMUM

Set this parameter equal to the elevation below which point the structure is fully immersed for all time . If this parameter is omitted, the elevation of the structure is compared against the instantaneous free surface to check for fluid surface penetration.

QUADRATIC

Include this parameter to indicate that quadratic interpolation of the wave data is used to determine information between grid points. If this parameter is omitted, linear interpolation is used.

Optional parameter for TYPE=USER: 

STOCHASTIC

Include this parameter to make the intermediate configuration available to user subroutine UWAVE. Set this parameter equal to a random number seed for use in stochastic analysis. If this parameter is omitted or is included without a value, a default value of 0.0 is used for the random number seed. This value is passed into user subroutine UWAVE. It is not used otherwise by ABAQUS/Aqua.

Data line to define Stokes fifth-order waves (TYPE=STOKES): 

First (and only) line:

  1. Wave height, .

  2. Period of wave, .

  3. Phase angle, , in degrees.

  4. Direction cosines giving the direction of travel of the wave, . In three-dimensional cases both - and -components are needed; in two-dimensional cases only the -component is used (in that case +1 means the wave travels in the direction of increasing, and 1 means a component traveling in the direction of decreasing).

Data lines to define Airy waves (TYPE=AIRY): 

First line:

  1. Wave component amplitude, .

  2. Wavelength of this component, (default), or wave period of this component, (if the parameter WAVE PERIOD is used).

  3. Phase angle of this component, , in degrees.

  4. -direction cosine defining the direction of the vector (the direction of travel for this wave component). In three-dimensional cases both - and -components are needed; in two-dimensional cases only the -component is used (in that case +1.0 means the wave travels in the direction of increasing, and 1.0 means a component traveling in the direction of decreasing).

  5. -direction cosine defining the direction of the vector (the direction of travel for this wave component). This component is not needed in two-dimensional cases.

Repeat this data line as often as necessary to define multiple wave trains; one line per wave component.

Data line to define gridded wave data (TYPE=GRIDDED): 

First (and only) line:

  1. -coordinate of the origin of the wave data grid.

  2. -coordinate of the origin of the wave data grid.

  3. -coordinate of the origin of the wave data grid.

  4. Direction cosine between the local -axis of the wave data grid and the global -axis. (Plus or minus one for two-dimensional analysis.)

  5. Direction cosine between the local -axis of the wave data grid and the global -axis. (Zero for two-dimensional analysis.)

Data line to define frequency versus wave amplitude data for stochastic user wave theory (TYPE=USER): 

First line:

  1. Frequency (in cycles per time, for stochastic analysis only).

  2. Wave amplitude.

Repeat this data line as often as necessary to define the wave spectrum. These data pairs are passed into user subroutine UWAVE. They are not used otherwise by ABAQUS/Aqua.