# block gridpoint apply command

Syntax

block gridpoint apply keyword ... <range>

Primary keywords:

Apply a boundary condition to block gridpoints.

force v

Set a load at location v (for deformable blocks only).

force-x f

Set a load in the $$x$$-direction.

force-y f

Set a load in the $$y$$-direction.

force-z f

Set a load in the $$z$$-direction.

Note

All loads are assumed to be constant and permanent by default, and are added to the existing permanent loads. Transient (time-varying) loading is applied if a $$fish$$ or $$table$$ keyword phrase is given on the same command line as the load (see below).

quiet

Synonym for Viscous

quiet-x <keyword ...>

Synonym for Viscous-X.

quiet-y <keyword ...>

Synonym for Viscous-Y.

quiet-z <keyword ...>

Synonym for Viscous-Z

velocity v

Set the velocity (for deformable blocks only).

velocity-normal f
Set the normal direction velocity for deformable blocks. The normal direction is defined as the normal to the block face. Velocity boundary conditions will be removed if velocity-normal 0 is applied in the same direction as the velocity condition. Two or more velocity-normal 0 conditions can be applied at the same vertex. If normal constraints that satisfy all conditions cannot be found, the condition reverts to block gridpoint apply velocity-x 0, block gridpoint apply velocity-y 0, block gridpoint apply velocity-z 0. Note also that if a normal velocity BC is applied to the same face twice, all degrees of freedom. will be fixed.
WARNING: This command requires that a whole face containing the vertex be within range. Unexpected results may occur depending on how the range is defined. Consider using block face apply instead.
velocity-x f

Set the $$x$$-direction velocity (for deformable blocks only).

velocity-y f

Set the $$y$$-direction velocity (for deformable blocks only).

velocity-z f

Set the $$z$$-direction velocity (for deformable blocks only).

viscous

Set a viscous boundary in all direction on the specified range.

Note

Viscous boundaries cannot be used together with a velocity boundary. Viscous boundaries may be combined with stress boundaries. Nonreflecting boundaries are available for dynamic analyses.

viscous-x <keyword ...>

Set a nonreflecting boundary in the $$x$$-direction.

viscous-y <keyword ...>

Set a nonreflecting boundary in the $$y$$-direction.

viscous-z <keyword ...>

Set a nonreflecting boundary in the $$z$$-direction.

reaction

Set point loads to be applied in the opposite direction to unbalanced forces at all vertices within the range. The command model cycle 1 should be given before this command reaction so that unbalanced forces are calculated. Any velocity boundary conditions will be removed when this command is applied.

reaction-x

Set point loads to be applied in the opposite $$x$$-direction.

reaction-y

Set point loads to be applied in the opposite $$y$$-direction.

reaction-z

Set point loads to be applied in the opposite $$z$$-direction.

source f

A heat-generating source, f, is applied as a point source of the specified strength (e.g., in $$W$$) at each gridpoint in the specified range. When a new source is applied to a gridpoint with an existing source, the new source strength replaces the existing source strength.

temperature f

Temperature is fixed to f at all gridpoints in the specified range. The fish or table keyword can be used to prescribe a temperature history. (See below.)

block apply Keyword Block

The keywords below are applicable to each of the following keywords of the $$block gridpoint apply$$ command: force, force-x, force-y, force-z, reaction, reaction-x, reaction-y, reaction-z, source, temperature, velocity, velocity-normal, velocity-x, velocity-y and velocity-z.

fish s

The specified FISH symbol is used to provide a multiplier.

table i

is the multiplier given by the TABLE command. TABLE n consists of a list of pairs: time, f(time). Linear interpolation is performed between the given discrete points.

verbose b

Increase messages to screen. The default setting is false.