# rblock attribute command

Syntax

rblock attribute keyword ... <range>

Primary keywords:

Set the value of rigid block attributes. This command is a synonym for the rblock initialize command. Individual attributes can be listed with the rblock list command and all attributes can be visualized.

Note

• Modification of the rigid block geometry will fail if the resulting rigid block would not fall entirely within the model domain.
• Rigid block attributes are characteristics of the rigid blocks such as position or size. These are distinct from rigid block properties (assigned with the rblock property command) that are surface properties of the rigid blocks that are used to fill contact model properties.
damp f [rbmodblock]

Rigid block local damping coefficient where f > 0. By default, f = 0.

density f [rbmodblock]

Rigid block density where f > 0. By default f = 0.

displacement v [rbmodblock]

Accumulated rigid block displacement vector as a result of cycling.

displacement-x f [rbmodblock]

The $$x$$-component of the accumulated rigid block displacement as a result of cycling.

displacement-y f [rbmodblock]

The $$y$$-component of accumulated displacement as a result of cycling.

displacement-z f (3D ONLY) [rbmodblock]

The $$z$$-component of accumulated displacement as a result of cycling.

euler v (3D ONLY) [rbmodblock]

Current orientation of Euler angles following the X,Y,Z convention (e.g., rotation about the $$x$$-axis followed by rotation about the y’-axis followed by rotation about the z’‘-axis) in degrees. The orientation is updated only when orientation tracking has been enabled (see model orientation-tracking command). When active, the current rigid block orientation can be visualized.

euler-x f (3D ONLY) [rbmodblock]

The $$x$$-euler angle (in degrees) of the current rigid block orientation. See the euler keyword for further details.

euler-y f (3D ONLY) [rbmodblock]

The $$y$$-euler angle (in degrees) of the current rigid block orientation. See the euler keyword for further details.

euler-z f (3D ONLY) [rbmodblock]

The $$z$$-euler angle (in degrees) of the current rigid block orientation. See the euler keyword for further details.

force-applied v [rbmodblock]

Force vector applied to rigid blocks.

force-applied-x f [rbmodblock]

The $$x$$-component of the applied force.

force-applied-y f [rbmodblock]

The $$y$$-component of the applied force.

force-applied-z f (3D ONLY) [rbmodblock]

The $$z$$-component of the applied force.

force-contact v [rbmodblock]

Sum of the contact force accumulated to the rigid blocks during the previous force-displacement update. This value will be modified during the next force-displacement update.

force-contact-x f [rbmodblock]

The $$x$$-component of the contact force.

force-contact-y f [rbmodblock]

The $$y$$-component of the contact force.

force-contact-z f (3D ONLY) [rbmodblock]

The $$z$$-component of the contact force.

fragment i

Fragment ID (see “Fragment”).

moi-11 f [rbmodblock]

11 component of the rigid block real moment of inertia. When modified, only the rigid block principal moments of inertia are modified and the other rigid block attributes are not changed. The specification of the rigid block principal moments of inertia via the command line or via FISH results in the principal moments of inertia being in a fixed state so that they will not be automatically updated when scaling a rigid block, changing the volume, or changing the density. The fix state can be modified in FISH (see the rblock.moi.fix intrinsic).

moi-12 f [rbmodblock]

12 component of the rigid block real moment of inertia. When modified, only the rigid block principal moments of inertia are modified and the other rigid block attributes are not changed. The specification of the rigid block principal moments of inertia via the command line or via FISH results in the principal moments of inertia being in a fixed state so that they will not be automatically updated when scaling a rigid block, changing the volume, or changing the density. The fix state can be modified in FISH (see the rblock.moi.fix intrinsic).

moi-13 f [rbmodblock]

13 component of the rigid block real moment of inertia. When modified, only the rigid block principal moments of inertia are modified and the other rigid block attributes are not changed. The specification of the rigid block principal moments of inertia via the command line or via FISH results in the principal moments of inertia being in a fixed state so that they will not be automatically updated when scaling a rigid block, changing the volume, or changing the density. The fix state can be modified in FISH (see the rblock.moi.fix intrinsic).

moi-22 f [rbmodblock]

22 component of the rigid block real moment of inertia. When modified, only the rigid block principal moments of inertia are modified and the other rigid block attributes are not changed. The specification of the rigid block principal moments of inertia via the command line or via FISH results in the principal moments of inertia being in a fixed state so that they will not be automatically updated when scaling a rigid block, changing the volume, or changing the density. The fix state can be modified in FISH (see the rblock.moi.fix intrinsic).

moi-23 f [rbmodblock]

23 component of the rigid block real moment of inertia. When modified, only the rigid block principal moments of inertia are modified and the other rigid block attributes are not changed. The specification of the rigid block principal moments of inertia via the command line or via FISH results in the principal moments of inertia being in a fixed state so that they will not be automatically updated when scaling a rigid block, changing the volume, or changing the density. The fix state can be modified in FISH (see the rblock.moi.fix intrinsic).

moi-33 f [rbmodblock]

33 component of the rigid block real moment of inertia. When modified, only the rigid block principal moments of inertia are modified and the other rigid block attributes are not changed. The specification of the rigid block principal moments of inertia via the command line or via FISH results in the principal moments of inertia being in a fixed state so that they will not be automatically updated when scaling a rigid block, changing the volume, or changing the density. The fix state can be modified in FISH (see the rblock.moi.fix intrinsic).

moi-principal fprin11 fprin22 fprin33 (3D ONLY) [rbmodblock]

Real principal moments of inertia. When modified, only the rigid block principal moments of inertia are modified and the other rigid block attributes are not changed. The specification of the rigid block principal moments of inertia via the command line or via FISH results in the principal moments of inertia being in a fixed state so that they will not be automatically updated when scaling a rigid block, changing the volume, or changing the density. The fix state can be modified in FISH (see the rblock.moi.fix intrinsic).

moment-applied fx fy fz (y- and z- components are 3D ONLY) [rbmodblock]

Moment applied to rigid blocks.

moment-applied-x f (3D ONLY) [rbmodblock]

The $$x$$-component of the moment applied to rigid blocks.

moment-applied-y f (3D ONLY) [rbmodblock]

The $$y$$-component of the moment applied to rigid blocks.

moment-applied-z f (3D ONLY) [rbmodblock]

The $$z$$-component of the moment applied to rigid blocks.

moment-contact fx fy fz (y- and z- components are 3D ONLY) [rbmodblock]

Sum of the contact moments accumulated to the rigid blocks during the previous force-displacement update. This value will be modified during the next force-displacement update.

moment-contact-x f (3D ONLY) [rbmodblock]

The $$x$$-component of the contact moment.

moment-contact-y f (3D ONLY) [rbmodblock]

The $$y$$-component of the contact moment.

moment-contact-z f (3D ONLY) [rbmodblock]

The $$z$$-component of the contact moment.

position v [rbmodblock]

Location of rigid block centroid.

position-x f [rbmodblock]

The $$x$$-component of the location of rigid block centroids.

position-y f [rbmodblock]

The $$y$$-component of the location of rigid block centroids.

position-z f (3D ONLY) [rbmodblock]

The $$z$$-component of the location of rigid block centroids.

rotation f (2D ONLY) [rbmodblock]

Current rigid block orientation. The orientation is updated only when orientation tracking has been enabled (see model orientation-tracking command).

spin fspinx fspiny fspinz (y- and z- components are 3D ONLY) [rbmodblock]

Rigid block angular velocity in radians per second.

spin-x f (3D ONLY) [rbmodblock]

The $$x$$-component of the rigid block angular velocity in radians per second.

spin-y f (3D ONLY) [rbmodblock]

The $$y$$-component of the rigid block angular velocity in radians per second.

spin-z f (3D ONLY) [rbmodblock]

The $$z$$-component of the rigid block angular velocity in radians per second.

velocity v [rbmodblock]

Rigid block translational velocity vector.

velocity-x f [rbmodblock]

The $$x$$-component of the rigid block velocity.

velocity-y f [rbmodblock]

The $$y$$-component of the rigid block velocity.

velocity-z f (3D ONLY) [rbmodblock]

The $$z$$-component of the rigid block velocity.

volume f [rbmodblock]

Rigid block volume. When modified, only the rigid block mass and real mass are modified and the other rigid block attributes based on volume are not changed. The specification of the volume via the command line or via FISH results in the principal moments of inertia being in a fixed state so that they will not be automatically updated when scaling a rigid block, changing the volume, or changing the density. The fixity state of the inertia can be modified in FISH (see the rblock.moi.fix intrinsic).

rblock attribute Keyword Block

Add f to the existing value.

Apply a linear gradient in each of the axes directions starting at the origin.

Apply a linear gradient in the $$x$$-direction starting at the origin.

Apply a linear gradient in the $$y$$-direction starting at the origin.

Apply a linear gradient in the $$z$$-direction starting at the origin.

multiply f

Multiply the existing value by f.

replace f

Replace the existing value with f.

Usage Examples

Set attributes for a rigid block.

rblock attribute density 2650 damp 0.7


[in specimendoc from Simple Rigid Block Bonded-Block Modeling (BBM)]

Set rigid block $$y$$-velocity along a gradient specified with inline FISH.

rblock attribute velocity-z 0.0 gradient 0 0 [-2.0 ＊ nvel / specHeight]


[in testsdoc from Simple Rigid Block Bonded-Block Modeling (BBM)]

Set the $$z$$-velocity of a single 3D rigid block by specifying its ID with a range.

rblock attribute vel-z 1 range id 31


Set multiple attributes (density and damping) for the range of rigid blocks not in the group “arch”.

rblock attribute density 0.0025 damp 0.7 range group 'arch' not


[in buttressdoc from Rigid Block Model of Flying Buttresses]