*GASKET THICKNESS BEHAVIOR

Specify a gasket thickness-direction behavior.

This option is used to define the behavior in the thickness direction for a gasket.

This page discusses:

Optional parameters

DEPENDENCIES

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

DIRECTION

Set DIRECTION=LOADING (default) to prescribe the loading curve of the model used to define the gasket thickness-direction behavior.

Set DIRECTION=UNLOADING to prescribe the unloading curves of the model used to define the gasket thickness-direction behavior.

INTERPOLATION

This parameter is relevant only when used in conjunction with TYPE=DAMAGE and DIRECTION=UNLOADING.

Set INTERPOLATION=NORMALIZED (default) to choose the interpolation scheme based on the normalized curves.

Set INTERPOLATION=DIRECT to choose the interpolation scheme based on the specified curves.

TENSILE STIFFNESS FACTOR

Set this parameter equal to the fraction of the initial compressive stiffness that defines the stiffness in tension. The default value is 10−3. This parameter can be used only with DIRECTION=LOADING.

TYPE

Set TYPE=DAMAGE to define a damage elasticity model for the gasket thickness-direction behavior.

Set TYPE=ELASTIC-PLASTIC (default) to define an elastic-plastic model for the gasket thickness-direction behavior.

VARIABLE

Set VARIABLE=FORCE to define the behavior in terms of force versus closure or force per unit length versus closure, depending on the element type with which this behavior is being used.

Set VARIABLE=STRESS (default) to define the behavior in terms of pressure versus closure.

The following parameters are optional, mutually exclusive, and can be used only with DIRECTION=LOADING

SLOPE DROP

Set this parameter equal to the relative drop in slope on the loading curve that defines the onset of plastic deformation. The default value is 0.1.

YIELD ONSET

Set this parameter equal to the closure value at which the onset of yield occurs. The specified value must correspond to a point on the loading curve at which the slope decreases.

Data lines to define the loading in terms of pressure versus closure (DIRECTION=LOADING and VARIABLE=STRESS)

First line

  1. Pressure. (This value cannot be negative.)

  2. Closure. (Units of L.) (This value cannot be negative.)

  3. Temperature, θ.

  4. First field variable.

  5. Etc., up to five field variables.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than five)

  1. Sixth field variable.

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

Repeat this set of data lines as often as necessary to define the dependence of the loading curve on temperature and field variables.

Data lines to define the loading in terms of force or force per unit length per closure (DIRECTION=LOADING and VARIABLE=FORCE)

First line

  1. Force or force per unit length. (This value cannot be negative.)

  2. Closure. (Units of L.) (This value cannot be negative.)

  3. Temperature, θ.

  4. First field variable.

  5. Etc., up to five field variables.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than five)

  1. Sixth field variable.

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

Repeat this set of data lines as often as necessary to define the dependence of the loading curve on temperature and field variables.

Data lines to define the unloading in terms of pressure versus closure for an elastic-plastic model (TYPE=ELASTIC-PLASTIC, DIRECTION=UNLOADING, and VARIABLE=STRESS)

First line

  1. Pressure. (This value cannot be negative.)

  2. Closure. (Units of L.) (This value must be positive.)

  3. Plastic closure. (Units of L.) (This value must be positive.)

  4. Temperature, θ.

  5. First field variable.

  6. Etc., up to four field variables.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)

  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 dependence of the unloading curve of the elastic-plastic model on temperature and field variables.

Data lines to define the unloading in terms of force or force per unit length versus closure for an elastic-plastic model (TYPE=ELASTIC-PLASTIC, DIRECTION=UNLOADING, and VARIABLE=FORCE)

First line

  1. Force or force per unit length. (This value cannot be negative.)

  2. Closure. (Units of L.) (This value must be positive.)

  3. Plastic closure. (Units of L.) (This value must be positive.)

  4. Temperature, θ.

  5. First field variable.

  6. Etc., up to four field variables.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)

  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 dependence of the unloading curve of the elastic-plastic model on temperature and field variables.

Data lines to define the unloading in terms of pressure versus closure for a damage model (TYPE=DAMAGE, DIRECTION=UNLOADING, and VARIABLE=STRESS)

First line

  1. Pressure. (This value cannot be negative.)

  2. Closure. (Units of L.) (This value cannot be negative.)

  3. Maximum closure reached while loading the gasket. (Units of L.) (This value must be positive.)

  4. Temperature, θ.

  5. First field variable.

  6. Etc., up to four field variables.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)

  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 dependence of the unloading curve of the damage model on temperature and field variables.

Data lines to define the unloading in terms of force or force per unit length versus closure for a damage model (TYPE=DAMAGE, DIRECTION=UNLOADING, and VARIABLE=FORCE)

First line

  1. Force or force per unit length. (This value cannot be negative.)

  2. Closure. (Units of L.) (This value cannot be negative.)

  3. Maximum closure reached while loading. (Units of L.) (This value must be positive.)

  4. Temperature, θ.

  5. First field variable.

  6. Etc., up to four field variables.

Subsequent lines (only needed if the DEPENDENCIES parameter has a value greater than four)

  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 dependence of the unloading curve of the damage model on temperature and field variables.

 

See Also
Defining the Gasket Behavior Directly Using a Gasket Behavior Model