`clump attribute`

command

Syntax

- clump attribute keyword ... <range>
Primary keywords:

damp density displacement displacement-x displacement-y displacement-z euler-x euler-y euler-z force-applied force-contact force-contact-x force-contact-y force-contact-z fragment moi-11 moi-12 moi-13 moi-22 moi-23 moi-33 moi-principal moment-applied moment-applied-x moment-applied-y moment-applied-z moment-contact moment-contact-x moment-contact-y moment-contact-z position position-x position-y position-z rotation spin spin-x spin-y spin-z velocity velocity-x velocity-y velocity-z volume

Set the value of clump attributes. This command is a synonym for the

`clump initialize`

command. Individual attributes can be listed with the`clump list`

command and all attributes can be visualized.Note

Modification of the clump geometry will fail if the resulting clump would not fall entirely within the model domain.

Clump attributes are characteristics of the clumps such as position or size. These are distinct from clump properties (assigned with the

`clump property`

command) that are surface properties of the clumps that are used to fill contact model properties.

- damp f [clmodblock]
Clump local damping coefficient where f > 0. By default, f = 0.

- density f [clmodblock]

- displacement v [clmodblock]
Accumulated clump displacement vector as a result of cycling.

- displacement-x f [clmodblock]
The \(x\)-component of the accumulated clump displacement as a result of cycling.

- displacement-y f [clmodblock]
The \(y\)-component of accumulated displacement as a result of cycling.

- displacement-z f (3D ONLY) [clmodblock]
The \(z\)-component of accumulated displacement as a result of cycling.

- euler-x f (3D ONLY) [clmodblock]
The \(x\)-euler angle (in degrees) of the current clump orientation. See the euler keyword for further details.

- euler-y f (3D ONLY) [clmodblock]
The \(y\)-euler angle (in degrees) of the current clump orientation. See the euler keyword for further details.

- euler-z f (3D ONLY) [clmodblock]
The \(z\)-euler angle (in degrees) of the current clump orientation. See the euler keyword for further details.

- force-applied v [clmodblock]
Force vector applied to clumps.

- force-contact v [clmodblock]
Sum of the contact force accumulated to the clumps during the previous force-displacement update. This value will be modified during the next force-displacement update.

- force-contact-x f [clmodblock]
The \(x\)-component of the contact force.

- force-contact-y f [clmodblock]
The \(y\)-component of the contact force.

- force-contact-z f (3D ONLY) [clmodblock]
The \(z\)-component of the contact force.

- moi-11 f [clmodblock]
11 component of the clump real moment of inertia. When modified, only the clump principal moments of inertia are modified and the other clump attributes are not changed (e.g., volume, pebble sizes). The specification of the clump 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 clump, changing the volume, or changing the density. The fix state can be modified in FISH (see the

`clump.moi.fix`

intrinsic).

- moi-12 f [clmodblock]
12 component of the clump real moment of inertia. When modified, only the clump principal moments of inertia are modified and the other clump attributes are not changed (e.g., volume, pebble sizes). The specification of the clump 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 clump, changing the volume, or changing the density. The fix state can be modified in FISH (see the

`clump.moi.fix`

intrinsic).

- moi-13 f [clmodblock]
13 component of the clump real moment of inertia. When modified, only the clump principal moments of inertia are modified and the other clump attributes are not changed (e.g., volume, pebble sizes). The specification of the clump 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 clump, changing the volume, or changing the density. The fix state can be modified in FISH (see the

`clump.moi.fix`

intrinsic).

- moi-22 f [clmodblock]
22 component of the clump real moment of inertia. When modified, only the clump principal moments of inertia are modified and the other clump attributes are not changed (e.g., volume, pebble sizes). The specification of the clump 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 clump, changing the volume, or changing the density. The fix state can be modified in FISH (see the

`clump.moi.fix`

intrinsic).

- moi-23 f [clmodblock]
23 component of the clump real moment of inertia. When modified, only the clump principal moments of inertia are modified and the other clump attributes are not changed (e.g., volume, pebble sizes). The specification of the clump 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 clump, changing the volume, or changing the density. The fix state can be modified in FISH (see the

`clump.moi.fix`

intrinsic).

- moi-33 f [clmodblock]
33 component of the clump real moment of inertia. When modified, only the clump principal moments of inertia are modified and the other clump attributes are not changed (e.g., volume, pebble sizes). The specification of the clump 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 clump, changing the volume, or changing the density. The fix state can be modified in FISH (see the

`clump.moi.fix`

intrinsic).

- moi-principal fprin11 fprin22 fprin33 (3D ONLY) [clmodblock]
Real principal moments of inertia. When modified, only the clump principal moments of inertia are modified and the other clump attributes are not changed (e.g., volume, pebble sizes). The specification of the clump 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 clump, changing the volume, or changing the density. The fix state can be modified in FISH (see the

`clump.moi.fix`

intrinsic).

- moment-applied fx fy fz (y- and z- components are 3D ONLY) [clmodblock]
Moment applied to clumps.

- moment-applied-x f (3D ONLY) [clmodblock]
The \(x\)-component of the moment applied to clumps.

- moment-applied-y f (3D ONLY) [clmodblock]
The \(y\)-component of the moment applied to clumps.

- moment-applied-z f (3D ONLY) [clmodblock]
The \(z\)-component of the moment applied to clumps.

- moment-contact fx fy fz (y- and z- components are 3D ONLY) [clmodblock]
Sum of the contact moments accumulated to the clumps during the previous force-displacement update. This value will be modified during the next force-displacement update.

- moment-contact-x f (3D ONLY) [clmodblock]
The \(x\)-component of the contact moment.

- moment-contact-y f (3D ONLY) [clmodblock]
The \(y\)-component of the contact moment.

- moment-contact-z f (3D ONLY) [clmodblock]
The \(z\)-component of the contact moment.

- position v [clmodblock]
Location of clump centroid.

- position-x f [clmodblock]
The \(x\)-component of the location of clump centroids.

- position-y f [clmodblock]
The \(y\)-component of the location of clump centroids.

- position-z f (3D ONLY) [clmodblock]
The \(z\)-component of the location of clump centroids.

- rotation f (2D ONLY) [clmodblock]
Current clump 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) [clmodblock]
Clump angular velocity in radians per second.

- spin-x f (3D ONLY) [clmodblock]
The \(x\)-component of the clump angular velocity in radians per second.

- spin-y f (3D ONLY) [clmodblock]
The \(y\)-component of the clump angular velocity in radians per second.

- spin-z f (3D ONLY) [clmodblock]
The \(z\)-component of the clump angular velocity in radians per second.

- velocity v [clmodblock]
Clump translational velocity vector.

- velocity-x f [clmodblock]
The \(x\)-component of the clump velocity.

- velocity-y f [clmodblock]
The \(y\)-component of the clump velocity.

- velocity-z f (3D ONLY) [clmodblock]
The \(z\)-component of the clump velocity.

- volume f [clmodblock]
Clump volume. When modified, only the clump mass and real mass are modified and the other clump attributes based on volume are not changed (e.g., moment of inertia, pebble sizes). 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 clump, changing the volume, or changing the density. The fixity state of the inertia can be modified in FISH (see the

`clump.moi.fix`

intrinsic).

`clump attribute`

Keyword Block

The following keywords may be used to modify the base value supplied. `damp`

, `density`

, `displacement`

, `displacement-x`

, `displacement-y`

, `displacement-z`

, `euler-x`

, `euler-y`

, `euler-z`

, `force-applied`

, `force-contact`

, `force-contact-x`

, `force-contact-y`

, `force-contact-z`

, `moi-11`

, `moi-12`

, `moi-13`

, `moi-22`

, `moi-23`

, `moi-33`

, `moi-principal`

, `moment-applied`

, `moment-applied-x`

, `moment-applied-y`

, `moment-applied-z`

, `moment-contact`

, `moment-contact-x`

, `moment-contact-y`

, `moment-contact-z`

, `position`

, `position-x`

, `position-y`

, `position-z`

, `rotation`

, `spin`

, `spin-x`

, `spin-y`

, `spin-z`

, `velocity`

, `velocity-x`

, `velocity-y`

, `velocity-z`

and `volume`

.

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

- gradient-x f
Apply a linear gradient in the \(x\)-direction starting at the origin.

- gradient-y f
Apply a linear gradient in the \(y\)-direction starting at the origin.

- gradient-z f (3D ONLY)
Apply a linear gradient in the \(z\)-direction starting at the origin.

Be aware of the distinction between *attributes* and *properties*!
The tutorial example “Attributes and Properties” discusses this issue in detail.

Usage Examples

Set density to 1.0e3 and the local damping coefficient to 0.7 for all clumps.

```
clump attribute density 1.0e3 damp 0.7
```

Set the velocity of the clump with ID 102 to (1e-2,1e-1).

```
clump attribute vel (1e-2,1e-1) range id=102
```

Set the density of all clumps to the value of the FISH variable `dens`

.

```
clump attribute density [dens]
```

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