Abaqus Keywords Reference Guide  
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*ELASTIC
Specify elastic material properties.

This option is used to define linear elastic moduli. In an Abaqus/Standard analysis spatially varying isotropic, orthotropic (including engineering constants and lamina), or anisotropic linear elastic moduli can be defined for solid continuum elements using a distribution (“Distribution definition,” Section 2.8.1 of the Abaqus Analysis User's Guide).

Products: Abaqus/Standard  Abaqus/Explicit  Abaqus/CAE  

Type: Model data

Level: Model  

Abaqus/CAE: Property module

Reference:

Optional parameters:

COMPRESSION FACTOR

This parameter is meaningful only for uncoupled traction-separation elastic behavior.

Set this parameter equal to the factor by which the elastic modulus, , must be scaled in compression. The use of a factor that is different from 1.0 results in different elastic moduli in tension and compression.

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 “Specifying field variable dependence” in “Material data definition,” Section 21.1.2 of the Abaqus Analysis User's Guide, for more information.

This parameter is not relevant in an Abaqus/Standard analysis if spatially varying elastic moduli are defined using a distribution. See “Distribution definition,” Section 2.8.1 of the Abaqus Analysis User's Guide.

MODULI

This parameter is applicable only when the *ELASTIC option is used in conjunction with the *VISCOELASTIC option.

Set MODULI=INSTANTANEOUS to indicate that the elastic material constants define the instantaneous behavior. This parameter value is not available for frequency domain viscoelasticity in an Abaqus/Standard analysis.

Set MODULI=LONG TERM (default) to indicate that the elastic material constants define the long-term behavior.

TYPE

Set TYPE=ANISOTROPIC to define fully anisotropic behavior.

Set TYPE=COUPLED TRACTION to define coupled traction behavior for cohesive elements.

Set TYPE=ENGINEERING CONSTANTS to define orthotropic behavior by giving the “engineering constants” (the generalized Young's moduli, the Poisson's ratios, and the shear moduli in the principal directions).

Set TYPE=ISOTROPIC (default) to define isotropic behavior.

Set TYPE=LAMINA to define an orthotropic material in plane stress.

Set TYPE=ORTHOTROPIC to define orthotropic behavior by giving the elastic stiffness matrix directly.

Set TYPE=SHEAR to define the (isotropic) shear elastic modulus. This parameter setting is applicable only in conjunction with the *EOS option in Abaqus/Explicit.

Set TYPE=SHORT FIBER to define laminate material properties for each layer in each shell element. This parameter setting is applicable only when using Abaqus/Standard in conjunction with the abaqus moldflow execution procedure. Any data lines given will be ignored. Material properties will be read from the ASCII neutral file identified as jobid.shf. See “Translating Moldflow data to Abaqus input files,” Section 3.2.41 of the Abaqus Analysis User's Guide for more information.

Set TYPE=TRACTION to define orthotropic shear behavior for warping elements or uncoupled traction behavior for cohesive elements.

When using a distribution to define elastic moduli, the TYPE parameter must be used to indicate the level of anisotropy in the elastic behavior. The level of anisotropy must be consistent with that defined in the distribution. See “Distribution definition,” Section 2.8.1 of the Abaqus Analysis User's Guide.

Data lines to define fully anisotropic elasticity directly (TYPE=ANISOTROPIC): 

First line:

  1. . (Units of FL–2.)

  2. .

  3. .

  4. .

  5. .

  6. .

  7. .

  8. .

Second line:

  1. .

  2. .

  3. .

  4. .

  5. .

  6. .

  7. .

  8. .

Third line:

  1. .

  2. .

  3. .

  4. .

  5. .

  6. Temperature.

  7. First field variable.

  8. Second field variable.

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

  1. Third 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 for cohesive elements (TYPE=COUPLED TRACTION): 

First line:

  1. .

  2. .

  3. .

  4. .

  5. .

  6. .

  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.

Data lines to define orthotropic elasticity with moduli (TYPE=ENGINEERING CONSTANTS): 

First line:

  1. .

  2. .

  3. .

  4. .

  5. .

  6. .

  7. .

  8. .

Second line:

  1. .

  2. Temperature, .

  3. First field variable.

  4. Second field variable.

  5. Etc., up to six field variables.

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

  1. Seventh 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 isotropic elasticity (TYPE=ISOTROPIC): 

First line:

  1. Young's modulus, E.

  2. Poisson's ratio, .

  3. Temperature, .

  4. First field variable.

  5. Second field variable.

  6. 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 elastic behavior as a function of temperature and other predefined field variables.

Data lines to define orthotropic elasticity in plane stress (TYPE=LAMINA): 

First line:

  1. .

  2. .

  3. .

  4. .

  5. . This shear modulus is needed to define transverse shear behavior in shells.

  6. . This shear modulus is needed to define transverse shear behavior in shells.

  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.

Data lines to define orthotropic elasticity directly (TYPE=ORTHOTROPIC): 

First line:

  1. . (Units of FL–2.)

  2. .

  3. .

  4. .

  5. .

  6. .

  7. .

  8. .

Second line:

  1. .

  2. Temperature.

  3. First field variable.

  4. Second field variable.

  5. Etc., up to six field variables.

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

  1. Seventh 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 isotropic elastic shear behavior (TYPE=SHEAR): 

First line:

  1. Shear modulus, G. (Units of FL–2.)

  2. Temperature.

  3. First field variable.

  4. Second field variable.

  5. Etc., up to six field variables.

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

  1. Seventh 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 shear modulus as a function of temperature and other predefined field variables.

Data lines to define orthotropic shear behavior for warping elements or uncoupled traction behavior for cohesive elements (TYPE=TRACTION): 

First line (only line for defining orthotropic shear behavior for warping elements; in this case the data cannot be defined as functions of temperature and/or field variables):

  1. E for warping elements; for cohesive elements.

  2. for warping elements; for cohesive elements.

  3. for warping elements; for cohesive elements.

  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 of cohesive elements):

  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 line to define spatially varying elastic behavior for solid continuum elements in an Abaqus/Standard analysis using a distribution. (Distributions are supported for TYPE=ISOTROPIC, TYPE=ENGINEERING CONSTANTS, TYPE=LAMINA, TYPE=ORTHOTROPIC, and TYPE=ANISOTROPIC): 

First line:

  1. Distribution name. The data defined in the distribution must be in units that are consistent with the prescribed TYPE.