`zone history`

command

Syntax

- zone history <name s > keyword
Primary keywords:

acceleration acceleration-x acceleration-y acceleration-z condition density density-fluid displacement displacement-x displacement-y displacement-z extra factor-of-safety fluid-biot-modulus fluid-bulk-modulus multiplier pore-pressure property property-fluid property-thermal ratio-local ratio-target saturation strain-increment strain-rate stress strength-stress-ratio stress-effective temperature timestep-dynamic unbalanced-force unbalanced-force-x unbalanced-force-y unbalanced-force-z velocity velocity-x velocity-y velocity-z

Add a history of a zone value. See the

`history`

command. The history can be assigned a name for later reference with the optional`name`

keyword; if not, the history will be given a default name based on its internally assigned id number.Zone histories can be taken of any scalar field variable, at any location encompassed by the zone. Once specified, the history location will travel with the zone in large strain mode.

The location of the history may be specified by: location in space; selecting the centroid of a zone with a specific ID number; or the location of the gridpoint with a specific ID number.

If the value is gridpoint-based, then a value is calculated using a weighting function inside the zone.

If the value is zone-based and the location does not correspond to the zone centroid, the value will be determined by a curve fitting algorithm. Which algorithm used can be specified in the following [zonehistoryblock]. By default, a value is considered constant within a zone.

Note that to take a history of a specific gridpoint, take a zone history using the

`gridpointid`

as the location, or specify the`position`

of a gridpoint.This will repeat in at least one other place

- acceleration [zonehistoryblock]
Acceleration magnitude at the gridpoint (only available if

`model configure dynamic`

has been specified).

- acceleration-x [zonehistoryblock]
\(x\)-acceleration at the gridpoint (only available if

`model configure dynamic`

has been specified).

- acceleration-y [zonehistoryblock]
\(y\)-acceleration at the gridpoint (only available if

`model configure dynamic`

has been specified).

- acceleration-z (3D Only) [zonehistoryblock]
\(z\)-acceleration at the gridpoint (only available if

`model configure dynamic`

has been specified).

- condition [zonehistoryblock]
Measure of how badly deformed a zone is. [URGENT: CS: content required for link here appears to need adding to doc set: Link to wherever the contents of section 1.1.5 in the Command Reference end up

- density [zonehistoryblock]
The density of the zone.

- density-fluid [zonehistoryblock]
The fluid density of the zone.

- displacement [zonehistoryblock]
Displacement magnitude at the gridpoint.

- displacement-x [zonehistoryblock]
\(x\)-displacement at the gridpoint.

- displacement-y [zonehistoryblock]
\(y\)-displacement at the gridpoint.

- displacement-z (3D Only) [zonehistoryblock]
\(z\)-displacement at the gridpoint.

- extra [zonehistoryblock]
Extra variable value. The extra variable index used will default to 1 and can be changed with the

`index`

modifier keyword. The value will by default come from the grid point extra variables, but this can be specified using the`source`

modifier keyword. The value will, by default, be treated as a scalar floating point type, but this can be specified using the`type`

modifier keyword.

- factor-of-safety [zonehistoryblock]
The largest factor of safety that remains stable for this grid point. Only available after a

`model factor-of-safety`

calculation. The`velocity-limit`

keyword is used to specify a velocity magnitude over which the gridpoint is considered unstable at a given factor of safety.

- fluid-biot-modulus [zonehistoryblock]
The fluid Biot modulus of the gridpoint.

- fluid-bulk-modulus [zonehistoryblock]
The fluid bulk modulus of the gridpoint.

- multiplier [zonehistoryblock]
The gridpoint multiplier used in dynamic multi-stepping.

- pore-pressure [zonehistoryblock]
By default, this will be the grid point pore pressure, but the zone average pore pressure can be specified by using the

`source`

keyword modifier.

- property name s [zonehistoryblock]
A property of the mechanical constitutive model of the zone. The value s is the keyword for the desired property, supplied as a string—for example, the property keyword

`bulk`

becomes`'bulk'`

in this command (quotes required). By default, it will be assumed the property is a floating point scalar, but this can be specified using the`type`

modifier keyword (one of the keywords available in the zone history Keyword Block).

- property-fluid name s [zonehistoryblock]
A property of the fluid constitutive model of the zone. The value s is the keyword for the desired property, supplied as a string (see

`property`

above). By default, it will be assumed the property is a floating point scalar, but this can be specified using the`type`

modifier keyword (one of the keywords available in the zone history Keyword Block).

- property-thermal name s [zonehistoryblock]
A property of the thermal constitutive model of the zone. The value s is the keyword for the desired property, supplied as a string (see

`property`

above). By default, it will be assumed the property is a floating point scalar, but this can be specified using the`type`

modifier keyword (one of the keywords available in the zone history Keyword Block). Try`zone history property type`

or`zone history property`

instead.

- ratio-local [zonehistoryblock]
The local unbalanced force ratio at each gridpoint. Like all results, this can be changed to the logarithm of the value by using the

`log`

keyword modifier.

- ratio-target [zonehistoryblock]
The target local gridpoint mechanical convergence ratio at each gridpoint. Like all results, this can be changed to the logarithm of the value by using the

`log`

keyword modifier.

- saturation [zonehistoryblock]
The saturation at the gridpoint (only available if

`model configure fluid`

has been specified).

- strain-increment [zonehistoryblock]
The strain increment tensor of the zone, determined by the current displacement field. Use the

`quantity`

keyword to specify which scalar value to retrieve from the tensor.

- strain-rate [zonehistoryblock]
The strain rate tensor of the zone, determined by the current velocity field. Use the

`quantity`

keyword to specify which scalar value to retrieve from the tensor.

- stress [zonehistoryblock]
The stress tensor of the zone, determined by the weighted average of the subzone stresses. Use the

`quantity`

keyword to specify which scalar value to retrieve from the tensor.

- strength-stress-ratio [zonehistoryblock]
The ratio of the current stress to a failure surface of the zone, as determined by the current zone constitutive model. Not all constitutive models support this calculation. If unsupported, the value returned will be 10. The value returned is generally held to a maximum of 10.

- stress-effective [zonehistoryblock]
The effective stress tensor of the zone, determined by the weighted average of the subzone stresses minus the zone-averaged pore pressure. Use the

`quantity`

keyword to specify which scalar value to retrieve from the tensor.

- temperature [zonehistoryblock]
The temperature at the gridpoints. The

`source`

modifier keyword can be used to specify that zone-based temperature should be used instead.

- timestep-dynamic [zonehistoryblock]
The local critical dynamic time step of that particular gridpoint. (only available if

`model configure dynamic`

has been specified).

- unbalanced-force [zonehistoryblock]
The unbalanced force magnitude at the gridpoint.

- unbalanced-force-x [zonehistoryblock]
\(x\)-unbalanced force at the gridpoint.

- unbalanced-force-y [zonehistoryblock]
\(y\)-unbalanced force at the gridpoint.

- unbalanced-force-z (3D Only) [zonehistoryblock]
\(z\)-unbalanced force at the gridpoint.

- velocity [zonehistoryblock]
The velocity magnitude at the gridpoint.

- velocity-x [zonehistoryblock]
\(x\)-velocity at the gridpoint.

- velocity-y [zonehistoryblock]
\(y\)-velocity at the gridpoint.

- velocity-z (3D Only) [zonehistoryblock]
\(z\)-velocity at the gridpoint.

`zone history`

Keyword Block

The following modifiers are available to specify additional information for the `zone history`

keywords. It is required that the location of the history must be specified using one of the keywords `position`

, `zoneid`

, or `gridpointid`

. They are applicable to all of the following keywords of the `zone history`

command. `acceleration`

, `acceleration-x`

, `acceleration-y`

, `acceleration-z`

, `condition`

, `density`

, `density-fluid`

, `displacement`

, `displacement-x`

, `displacement-y`

, `displacement-z`

, `extra`

, `factor-of-safety`

, `fluid-biot-modulus`

, `fluid-bulk-modulus`

, `multiplier`

, `pore-pressure`

, `property`

, `property-fluid`

, `property-thermal`

, `ratio-local`

, `ratio-target`

, `saturation`

, `strain-increment`

, `strain-rate`

, `strength-stress-ratio`

, `stress`

, `stress-effective`

, `temperature`

, `timestep-dynamic`

, `unbalanced-force`

, `unbalanced-force-x`

, `unbalanced-force-y`

, `unbalanced-force-z`

, `velocity`

, `velocity-x`

, `velocity-y`

and `velocity-z`

.

- component keyword
This keyword selects which scalar to retrieve from a vector type value, such as velocity or displacement. If the value type is not a vector, this setting is ignored. The available options are:

- x
\(x\)-component of the vector.

- y
\(y\)-component of the vector.

- z (3D Only)
\(z\)-component of the vector.

- magnitude
Vector magnitude.

- index i
For keywords that require it (most notably

`extra`

), this specifies the index that should be used. The default value will be 1.

- gravity b
If

`on`

, then gravitational forces are included in the returned applied force. The default is`off`

.

- gridpointid i
Specify the location of the history by the location of the gridpoint with ID number i.

- label s
Assign a label to the history, used in prints and plots.

- log b
If

`on`

, the returned number is the base 10 log of the absolute value of the original value. The default is`off`

.

- method
Specifies the method of calculation used to bring zone-based quantities to arbitrary locations in space (including at gridpoint positions).

- constant
Assume values are constant inside zones. This is the default option. Values at gridpoints or at zone boundaries will pick one adjacent zone to use.

- average
Use a volume-weighted average of all the zones connected to the gridpoint.

- inverse-distance-weight
Use a weighted average of up to 32 zones in the immediate vicinity of the point. The weighting is determined by a power of the distance of the zone centroid from the specified point.

- power f
Specify the power of the distance used to weight values. The default power is 3.0.

- radius-ratio f
Specify the ratio of the maximum distance from the point of the zones selected, to the ratio used to calculate weighted values. Zones farther from this value are discounted. The default value is 0.75.

- polynomial <tolerance f > (3D Only)
Use a fit to a polynomial function based on the zones in the vicinity of the point. Degenerate degrees of freedom are detected and removed. The optional

`tolerance`

flag can be used to change the value used to detect a degeneracy. The default value is`1e-7`

.

- name s
Certain keywords (most notably

`property`

) require a name value to be fully specified. This will determine the specific property name retrieved.

- null <keyword>
Specify the criteria used to ignore zone values. By default,

`mechanical`

null zones are ignored.

- fluid b
Zones with a null fluid constitutive model are also ignored if this is set to

`on`

.

- mechanical b
Zones with a null mechanical constitutive model are ignored if this is set to

`on`

(this is the default).

- thermal b
Zones with a null thermal constitutive model are ignored if this is set to

`on`

.

- quantity keyword
Select which scalar to retrieve from a symmetric tensor type value, such as stress or strain. If the value type is not a tensor, this setting is ignored. The available options are:

- intermediate
Intermediate principal stress.

- maximum
The maximum (most positive) value of principal stress. Note that in FLAC compressive stresses are negative.

- mean
The mean pressure value, defined as the trace of the tensor divided by 3. For stresses this is most often referred to as the pressure.

- minimum
The minimum (most negative) principal stress. Note that in FLAC compressive stresses are negative.

- norm
The norm of the strain rate; see the equation in Zone Field Data Names

- octahedral
Octahedral stress; see the equation in Zone Field Data Names.

- shear-maximum
Maximum shear stress.

- total-measure
Distance of tensor value to the origin in principal space.

- volumetric
Volumetric change, or trace.

- von-mises
Von Mises measure; see the equation in Zone Field Data Names.

- xx

xx-component of the tensor.

- xy

xy-component of the tensor.

- xz (3D Only)

xz-component of the tensor.

- yy

yy-component of the tensor.

- yz (3D Only)

yz-component of the tensor.

- zz

zz-component of the tensor.

- source keyword
Certain keywords (like

`extra`

and`pore-pressure`

) can be retrieved either from the zone structure or from the gridpoint structure. The default value is`gridpoint`

.

- gridpoint
Values are retrieved directly from the gridpoint.

- zone
Values are retrieved from the zone.

- stress b
A few of the tensor type

`quantity`

options have different effects depending if the value is considered a stress. When coming from a value like`extra`

, this cannot be determined automatically. Setting`stress on`

identifies the incoming tensor value as a stress quantity.

- type keyword
In certain cases the type (scalar, vector, or tensor) of the value cannot necessarily be determined ahead of time. Extra variables, for example, can hold values of all three types. This keyword allows specifying which type it is assumed to be. If the original value type does not match, 0.0 is returned.

- scalar
A scalar float type. This is the default.

- vector
A vector type.

- tensor
A tensor type.

- velocity-limit f
Specify the velocity limit used to determine if an object is stable or not for the

`factor-of-safety`

value. The default value is`1e-4`

.

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