ABAQUS Volume II: I–Z - Manual (Page 592)

*USER ELEMENT
Required parameters if the FILE parameter is included:
OLD ELEMENT
Set this parameter equal to the element number that was assigned to the element whose matrices are
being read. This parameter can also be set to a substructure identifier to read a substructure matrix
from an ABAQUS/Standard results file.
STEP
Set this parameter equal to the step number in which the element matrix was written. This parameter
is not required if using a substructure whose matrix was output during its generation.
INCREMENT
Set this parameter equal to the increment number in which the element matrix was written. This
parameter is not required if using a substructure whose matrix was output during its generation.
Required parameters if the FILE parameter is omitted:
LINEAR
Include this parameter to indicate that the behavior of the element type is linear and is defined by
a stiffness matrix and/or a mass matrix. The *MATRIX option is required to define the element’s
behavior.
NODES
Set this parameter equal to the number of nodes associated with an element of this type.
Optional parameters if the FILE parameter is omitted:
COORDINATES
ABAQUS/Standard assigns space to store the coordinate values at each node in user subroutine
UEL
. The default number of coordinate values is equal to the largest active degree of freedom of
the user element with a maximum of 3. Use the COORDINATES parameter to increase the number
of coordinate values.
UNSYMM
Include this parameter if the element matrices are not symmetric. This parameter will cause
ABAQUS/Standard to use its unsymmetric equation solution capability.
The presence or absence of this parameter determines the form in which the matrices must be
provided for reading.
Data lines if the FILE parameter is omitted:
First line:
1. Enter the list of active degrees of freedom at the first node of the element (as determined by
the connectivity list). The rule in “Conventions,” Section 1.2.2 of the ABAQUS Analysis
User’s Manual, regarding which degrees of freedom can be used for displacement, rotation,
temperature, etc. must be conformed to.
20.5–2
ABAQUS Version 6.1 Module: ID:
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