This option is used to define a failure surface and the flow parameters for a single joint system or for bulk material failure in the elastic-plastic model of a jointed material, or it can be used to define shear retention in open joints. Up to three joint systems can be defined for each material point.
Set this parameter equal to the number of field variable dependencies included in the definition of the parameters of the model, in addition to temperature. If this parameter is omitted, it is assumed that the parameters depend only on temperature. See Material Data Definition for more information.
JOINT DIRECTION
Set this parameter equal to the name of the ORIENTATION used to define the direction of a joint system. This use of the ORIENTATION option does not affect the output of components of stress and strain—it only defines the joint orientation in the original configuration. Omit this parameter to give the bulk material failure parameters. The JOINT DIRECTION parameter cannot be used with the SHEAR RETENTION parameter.
NO SEPARATION
Include this parameter to prevent the joint from opening. This parameter must be used in conjunction with the JOINT DIRECTION parameter.
SHEAR RETENTION
Include this parameter to define shear retention in open joints. If this parameter is omitted, zero shear retention is assumed. The SHEAR RETENTION parameter cannot be used with the JOINT DIRECTION parameter.
Data lines defining failure surface and flow parameters (SHEAR RETENTION omitted)
First line
Angle of friction, , for this system. Give the value in degrees.
Dilation angle, , for this system. Give the value in degrees.
Cohesion, d, for this system. (Units of FL−2.)
Temperature.
First field variable.
Second field variable.
Etc., up to four field variables.
Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)
Fifth field variable.
Etc., up to eight field variables per line.
Repeat this set of data lines as often as necessary to define the dependence of the failure and surface flow parameters on temperature and other predefined field variables.
Data lines defining the shear retention in open joints (SHEAR RETENTION included)
First line
Fraction of elastic shear modulus retained when joints are open, . This value cannot be less than zero.
Temperature.
First field variable.
Second field variable.
Etc., up to six field variables.
Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than six)
Seventh field variable.
Etc., up to eight field variables per line.
Repeat this set of data lines as often as necessary to define the dependence of the shear retention on temperature and other predefined field variables.