# fracture create command

Syntax

fracture create keyword ...

Primary keywords:

Create a deterministic fracture.

Note

• A model domain must be specified prior to fracture addition.
• Fractures will be clipped at the model domain boundary if they extend beyond the model domain.

If the specified DFN specified by the dfn keyword does not exist a new DFN is created. If a DFN is not specified then a new DFN is created with the next available ID and name dfnXX, where XX is the DFN ID. This command creates a {line segment fracture in 2D; disk fracture in 3D}. The command contrasts with the fracture generate command, which generates fractures based on a stochastic description of a fracture.

dfn s

Add the fracture to the DFN with name s.

dfn-dominance i

If a new DFN is created, then its dominance is set to i, where i is greater than 1. The dominance is used during contact model assignment, when a contact intersects multiple fractures from different DFNs. The fractures from the DFN with the lowest DFN dominance will be further scrutinized by their individual dominance values to assign the appropriate contact model properties. If not specified, then the next available dominance is used. See the fracture contact-model command for further details.

dip f

Dip angle of the fracture in degrees, where f is in the range {[0,180] in 2D; [0,90] in 3D}. In 2D, dip is the clockwise angle measured from the positive $$x$$-axis. In 3D, dip is the angle from the dip direction projected on the $$xy$$-plane to the fracture surface measured in the negative $$z$$-direction. By default, f = 0.

dip-direction f (3D only)

Dip direction of the fracture in degrees, as measured in a clockwise fashion from the positive $$y$$-axis where f is in the range [0,360]. By default, f is 0.0.

dominance i

Specify the fracture dominance where i is greater than 1. If not specified, then the next available fracture dominance value is used. Should a contact intersect numerous fractures from a single DFN, then the fracture with the lowest dominance is used to assign the appropriate contact model and properties. See the fracture contact-model command for further details.

group s <slot slot >

Assign the group name s to the fracture and optionally set the slot to slot.

intersection-set s

Fracture intersections with the newly created fracture are calculated and added to the intersection set with name s.

position v

Position of the fracture center. The fracture position must fall within the model domain unless the skip-errors keyword is specified. By default, the position is the origin.

size f

Size of the fracture. By default, this is 1. The size is the {fracture length in 2D; disk diameter in 3D}.

skip-errors

Indicate that the command will return a warning instead of an error if the fracture creation fails. When this keyword is given, the fracture position is not required to fall within the model domain.

Usage Example

The following example illustrates how the fracture create command can be used to create a single fracture in a new DFN (3D).

model new
model domain extent -5 5 -5 5 -5 5
;Create a deterministic fracture
fracture create                         ...
position        (1.,1.,1.)  ...
dip             45.0        ...
dip-direction   230.0       ...
size            1.0         ...
group           '5'         ...
dfn             'newDFN'
program return