Product: ABAQUS/Standard
User subroutine UMESHMOTION:
can be used to define the motion of nodes in an adaptive mesh constraint node set; and
can call utility routines GETVRN, GETNODETOELEMCONN, and GETVRMAVGATNODE to access results data at the node.
You are provided with access to the values of the node point quantities at the end of the increment through the utility routine GETVRN described in “Obtaining node point information,” Section 2.1.7. You can also access values of material point quantities extrapolated to, and averaged, at nodes at the end of the increment through the utility routine GETVRMAVGATNODE described in “Obtaining material point information averaged at a node,” Section 2.1.6. GETVRMAVGATNODE requires the list of elements attached to the node, which is obtained by calling the utility routine GETNODETOELEMCONN described in “Obtaining node to element connectivity,” Section 2.1.8.
SUBROUTINE UMESHMOTION(UREF,ULOCAL,NODE,NNDOF,
* LNODETYPE,ALOCAL,NDIM,TIME,DTIME,PNEWDT,
* KSTEP,KINC,KMESHSWEEP,JMATYP,JGVBLOCK,LSMOOTH)
C
INCLUDE 'ABA_PARAM.INC'
C
DIMENSION ULOCAL(NDIM),JELEMLIST(*)
DIMENSION ALOCAL(NDIM,*),TIME(2)
DIMENSION JMATYP(*),JGVBLOCK(*)
C
user coding to define ULOCAL
and, optionally PNEWDT
RETURN
ENDULOCAL
Components of the mesh displacement or velocity of the adaptive mesh constraint node, described in the coordinate system ALOCAL. ULOCAL will be passed into the routine as values determined by the mesh smoothing algorithm.
PNEWDT
Ratio of suggested new time increment to the time increment currently being used (DTIME, see below). This variable allows you to provide input to the automatic time incrementation algorithms in ABAQUS/Standard (if automatic time incrementation is chosen).
PNEWDT is set to a large value before each call to UMESHMOTION.
If PNEWDT is redefined to be less than 1.0, ABAQUS/Standard must abandon the time increment and attempt it again with a smaller time increment. The suggested new time increment provided to the automatic time integration algorithms is PNEWDT × DTIME, where the PNEWDT used is the minimum value for all calls to user subroutines that allow redefinition of PNEWDT for this iteration.
If PNEWDT is given a value that is greater than 1.0 for all calls to user subroutines for this iteration and the increment converges in this iteration, ABAQUS/Standard may increase the time increment. The suggested new time increment provided to the automatic time integration algorithms is PNEWDT × DTIME, where the PNEWDT used is the minimum value for all calls to user subroutines for this iteration.
If automatic time incrementation is not selected in the analysis procedure, values of PNEWDT greater than 1.0 will be ignored and values of PNEWDT less than 1.0 will cause the job to terminate.
LSMOOTH
Flag specifying that surface smoothing be applied after application of the mesh motion constraint. Set LSMOOTH to 1 to enable surface smoothing. When this flag is set, the constraint defined in ULOCAL will be modified by the smoothing algorithm. In cases where ULOCAL describes mesh motion normal to a surface, the smoothing will have a minor impact on this normal component of mesh motion.
UREF
The value of the user-specified displacement or velocity provided as part of the adaptive mesh constraint definition. This value is updated based on any amplitude definitions used with the adaptive mesh constraint or default ramp amplitude variations associated with the current step.
NODE
Node number.
NNDOF
Number of degrees of freedom at the node.
LNODETYPE
Node type flag.
LNODETYPE=1 indicates that the node is on the interior of the adaptive mesh region.
LNODETYPE=2 indicates that the node is involved in a tied constraint.
LNODETYPE=3 indicates that the node is at the corner of the boundary of an adaptive mesh region.
LNODETYPE=4 indicates that the node lies on the edge of a boundary of an adaptive mesh region.
LNODETYPE=5 indicates that the node lies on a flat surface on a boundary of the adaptive mesh region.
LNODETYPE=6 indicates that the node participates in a constraint (other than a tied constraint) as a master node.
LNODETYPE=7 indicates that the node participates in a constraint (other than a tied constraint) as a slave node.
ALOCAL
Local coordinate system aligned with the tangent to the adaptive mesh domain at the node. If the node is on the interior of the adaptive mesh domain, ALOCAL will be set to the identity matrix. In other cases the 1-direction is along an edge or in the plane of a flat surface. When NDIM=2, the 2-direction is normal to the surface. When NDIM=3, the 2-direction also lies in the plane of a flat surface or is arbitrary if the node is on an edge. When NDIM=3 the 3-direction is normal to the surface or is arbitrary if the node is on an edge.
NDIM
Number of coordinate dimensions.
TIME(1)
Current value of step time.
TIME(2)
Current value of total time.
DTIME
Time increment.
KSTEP
Step number.
KINC
Increment number.
KMESHSWEEP
Mesh sweep number.
JMATYP
Variable that must be passed into the GETVRMAVGATNODE utility routine to access local results at the node.
JGVBLOCK
Variable that must be passed into the GETVRN, GETNODETOELEMCONN, and GETVRMAVGATNODE utility routines to access local results at the node.