# zone gridpoint fix command

Syntax

zone gridpoint fix keyword <range>

Primary keywords:

Fix a property at all gridpoints in the range. If a fixed displacement is required, the appropriate velocities should be initialized to zero. (Zero velocity is the default on start-up.) To provide a boundary condition to a surface of the model, see the zone face apply command.

acceleration <v >

Fix acceleration. If v is given, acceleration is fixed at that value. This is only available if model configure dynamic has been specified. The value is always in terms of the gridpoint local coordinate system, if any.

acceleration-x <f >

Fix $$x$$-acceleration. If f is given, $$x$$-acceleration is fixed at that value. This is only available if model configure dynamic has been specified. The value is always in terms of the gridpoint local coordinate system, if any.

acceleration-y <f >

Fix $$y$$-acceleration. If f is given, $$y$$-acceleration is fixed at that value. This is only available if model configure dynamic has been specified. The value is always in terms of the gridpoint local coordinate system, if any.

acceleration-z <f > (3D ONLY)

Fix $$z$$-acceleration. If f is given, $$z$$-acceleration is fixed at that value. This is only available if model configure dynamic has been specified. The value is always in terms of the gridpoint local coordinate system, if any.

force-applied <v >

Fix applied force. If v is given, applied force is fixed at that value. Note that this value is independent of either force-based apply conditions, or forces applied via FISH. The value is always in terms of the gridpoint local coordinate system, if any.

force-applied <v >

Fix applied force. If v is given, applied force is fixed at that value. Note that this value is independent of either force-based apply conditions, or forces applied via FISH. The value is always in terms of the gridpoint local coordinate system, if any.

force-applied-x <f >

Fix applied force in the x-direction. If f is given, applied force in the x-direction is fixed at that value. Note that this value is independent of either force-based apply conditions, or forces applied via FISH. The value is always in terms of the gridpoint local coordinate system, if any.

force-applied-y <f >

Fix applied force in the y-direction. If f is given, applied force in the y-direction is fixed at that value. Note that this value is independent of either force-based apply conditions, or forces applied via FISH. The value is always in terms of the gridpoint local coordinate system, if any.

force-applied-z <f > (3D ONLY)

Fix applied force in the z-direction. If f is given, applied force in the z-direction is fixed at that value. Note that this value is independent of either force-based apply conditions, or forces applied via FISH. The value is always in terms of the gridpoint local coordinate system, if any.

Uses Head to calculate and fix pore pressures. Fluid Density and Gravity need to be previously defined. If f is given, the calculated pore pressure is fixed at that value. Note that if the current pore-pressure is changed, the difference is stored in the fluid-mechanical coupling logic and will be applied to the zones in the next mechanical step. This will adjust the total stress but keep the effective stress constant. This is in comparison to using the zone gridpoint initialize head or zone gridpoint initialize pore-pressure, which will keep the total stress constant but change the effective stress.

pore-pressure <f >

Fix pore pressures. If f is given, the pore pressure is fixed at that value. Note that if the current pore-pressure is changed, the difference is stored in the fluid-mechanical coupling logic and will be applied to the zones in the next mechanical step. This will adjust the total stress but keep the effective stress constant. This is in comparison to using the zone gridpoint initialize pore-pressure, which will keep the total stress constant but change the effective stress.

source <f >

Apply a thermal source to the gridpoint. Note that this value is independent of sources applied either by apply commands or by FISH.

temperature <f >

Fixes temperatures. If f is given, the temperature is fixed at that value. This is only available if model configure thermal has been specified.

velocity <v >

Fixes velocity. If v is given, velocity is fixed at that value. The value is always in terms of the gridpoint local coordinate system, if any.

velocity-x <f >

Fixes $$x$$-velocity. If f is given, the $$x$$-velocity is fixed at that value. The value is always in terms of the gridpoint local coordinate system, if any.

velocity-y <f >

Fixes $$y$$-velocity. If f is given, the $$y$$-velocity is fixed at that value. The value is always in terms of the gridpoint local coordinate system, if any.

velocity-z <f > (3D ONLY)

Fixes $$z$$-velocity. If f is given, the $$z$$-velocity is fixed at that value. The value is always in terms of the gridpoint local coordinate system, if any.

well <f >

Applies a fluid source to the gridpoint. This is only available if model configure fluid has been specified.

zone gridpoint fix Keyword Block

The following keywords may be used to modify a supplied value. If the description of the modifier keyword mentions what type of value it may be applied to (e.g. scalar value, vector value, etc.), be sure there is a match between the modifier and the main keyword value.

Add a value to an exisiting value.

multiply

Multiply the exisiting value by a factor.