# *COHESIVE BEHAVIOR

 Specify contact cohesive behavior properties. This option is used to define contact cohesive behavior in a mechanical contact analysis. It must be used in conjunction with the SURFACE INTERACTION option.
 Related Topics *SURFACE INTERACTION In Other Guides Contact cohesive behavior

ProductsAbaqus/StandardAbaqus/ExplicitAbaqus/CAE

TypeModel data

LevelModel

Abaqus/CAEInteraction module

## Optional, mutually exclusive parameters

COHERE

Set COHERE=ORIGINAL CONTACTS (default) to restrict cohesive behavior to only those nodes of the slave surface that are in contact with the master surface at the beginning of a simulation.

Set COHERE=FIRST CONTACTS to establish cohesive bonds for active contact constraints at the beginning of a simulation plus the first time an initially not-in-contact region comes into contact during a simulation. This parameter value is not allowed for general contact in Abaqus/Standard.

Set COHERE=REPEATED CONTACTS to allow cohesive rebonding each time contact is established, even for nodes previously involved in cohesive contact that have fully damaged and debonded.

ELIGIBILITY

Set ELIGIBILITY=ORIGINAL CONTACTS (default) to restrict cohesive behavior to only those nodes of the slave surface that are in contact with the master surface at the beginning of a simulation.

Set ELIGIBILITY=CURRENT CONTACTS to define cohesive behavior not only for all nodes of the slave surface that are in contact with the master surface at the start of a step, but also for slave nodes that are not initially in contact but may come in contact during the course of a step. This setting must be used together with the REPEATED CONTACTS parameter for general contact in Abaqus/Standard.

Set ELIGIBILITY=SPECIFIED CONTACTS to restrict cohesive behavior to a subset of the slave nodes defined using INITIAL CONDITIONS, TYPE=CONTACT. This parameter value is available only for contact pairs in Abaqus/Standard.

## Optional parameters

DEPENDENCIES

Set this parameter equal to the number of field variable dependencies included in the definition of the moduli. If this parameter is omitted, it is assumed that the moduli are constant or depend only on temperature. See Material data definition for more information.

REPEATED CONTACTS

Include this parameter to modify the default post-failure behavior when progressive damage has been defined and the COHERE parameter is not specified. By default, cohesive behavior is not enforced for nodes on the slave surface once ultimate failure has occurred at those nodes. Use the REPEATED CONTACTS parameter to enforce cohesive behavior for recurrent contacts at nodes on the slave surface subsequent to ultimate failure.

TYPE

Set TYPE=UNCOUPLED (default) to define uncoupled traction behavior.

Set TYPE=COUPLED to define coupled traction behavior.

## Data lines to define uncoupled traction separation behavior (TYPE=UNCOUPLED)

First line
1. $Kn⁢n$. (Units of FL−3.)

2. $Ks⁢s$.

3. $Kt⁢t$.

4. Temperature.

5. First field variable.

6. Etc., up to four field variables per line.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four; relevant only for defining uncoupled traction behavior)
1. Fifth field variable.

2. Etc., up to eight field variables per line.

Repeat this set of data lines as often as necessary to define the elastic behavior as a function of temperature and other predefined field variables.

## Data lines to define coupled traction separation behavior (TYPE=COUPLED)

First line
1. $Kn⁢n$. (Units of FL−3.)

2. $Ks⁢s$.

3. $Kt⁢t$.

4. $Kn⁢s$.

5. $Kn⁢t$.

6. $Ks⁢t$.

7. Temperature.

8. First field variable.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than one)
1. Second field variable.

2. Etc., up to eight field variables per line.

Repeat this set of data lines as often as necessary to define the elastic behavior as a function of temperature and other predefined field variables.