Obtaining Material Point Information from User Subroutine UVAREL

Utility routine getElMPtVar can be called from user subroutine UVAREL to obtain material point information within an element.

This page discusses:

See Also
UVAREL
In Other Guides
Using Abaqus/Standard Output Variable Identifiers

Products Abaqus/Standard

Utility Routine Interface

character*3 flgray(15)
      dimension array(15),jarray(15)
...
 call getElMPtVar('Var', kPt, kLayer, kSpt, array, jArray, flgray, jError, abqInternal)

Variables to Be Provided to the Utility Routine

Var

Output variable key from the table in Element Integration Point Variables. The applicable keys are listed in the output table as being available for output at the element integration points; for example, S for stress.

kPt

Integration point number.

kLayer

Composite layer number.

kSpt

Section point number within the current layer.

abqInternal

Variable that must be passed into utility routine getElMPtVar. The calling user subroutine provides this variable.

Variables Returned from the Utility Routine

array

Real array containing individual components of the output variable.

jArray

Integer array containing individual components of the output variable.

flgray

Character array containing flags corresponding to the individual components. Flags will contain either YES, NO, or N/A (not applicable).

jError

Return code (0 – no error, 1 – output request error or all components of the output request are zero).

Available Output Variable Keys

Only output variable keys that are valid for material point output are available for use with getElMPtVar. In general, if a key corresponds to a collective output variable (rather than to an individual component), it can be used with getElMPtVar. For example, S for the stress tensor can be used, but any individual component of stress (for example, S11) cannot be used. The collective output variable keys are distinguished from their individual components by the fact that they have the word "yes" after the category .fil in the tables in Using Abaqus/Standard Output Variable Identifiers. Supported Element Types and Output Variable Keys lists output variable keys that can and cannot be used with getElMPtVar.

Utility routine getElMPtVar returns array, jArray, and flgray, which correspond to the real-valued components, integer-valued components, and the flags associated with the request Var, respectively. If any array component is not applicable for a given request, its value is returned as the initialized value: 0.0 in array, 0 in jArray, and N/A in flgray. getElMPtVar returns the error flag jError=1 any time a request key is not recognized, the request is not valid (such as requesting transverse shear stress for a shell element that uses thin shell theory), or all of the output components requested are zero; otherwise, jError=0.

Ordering of Returned Components

The components for a request are written as follows:

  • Single index components (and requests without components) are returned in positions 1, 2, 3, etc.
  • Double index components are returned in the order 11, 22, 33, 12, 13, 23 for symmetric tensors, followed by 21, 31, 32 for unsymmetric tensors (deformation gradient).
Therefore, the stresses for a plane stress element are returned as array(1)=S11, array(2)=S22, array(3)=0.0, and array(4)=S12. Three values are always returned for principal value requests, with the minimum value first and the maximum value third, regardless of the dimensionality of the analysis.

The description of the output variable (see Abaqus/Standard Output Variable Identifiers) determines which components are retrieved with getElMPtVar.

Analysis Time for which Values Are Returned

When you request a material point quantity with the utility routine, getElMPtVar always returns the requested quantities with the values at the end of the current increment.

Accessing State-Dependent Variables

If you use getElMPtVar to access state-dependent variables (output variable key SDV) and more than 15 state-dependent variables have been defined in the analysis, you must change the dimension statement for array and jArray so that you dimension these arrays to the maximum number of state-dependent variables.

Supported Element Types and Output Variable Keys

This utility routine can be called from user subroutine UVAREL, which is supported only for continuum solid, solid shell, conventional shell, and continuum shell elements. All other element types are unsupported.

You cannot use output variable SVOL with getElMPtVar.