DEFORM-3D Keyword Documentation Part 3 pps

DEFBWD DEFBWD Flag OPERAND DESCRIPTION DEFAULT Flag Flag indicating if deformation profile 0 optimization is performed = 0 Deformation profile optimization is not performed = 1 Deformati

DEFBWD

DEFBWD Flag

OPERAND DESCRIPTION DEFAULT

Flag Flag indicating if deformation profile 0

optimization is performed

= 0 Deformation profile optimization is not performed

= 1 Deformation profile optimization is performed

DEFINITION

DEFBWD specifies if profile optimization is to be performed during a deformation simulation

REMARKS

If Flag =1, the profile will be optimized every time a deformation boundary

condition is updated (node contact or node separation)

Profile optimization should be done in the mesh generator when possible If the profile cannot be optimized in the mesh generator, deformation profile optimization should be used

If profile optimization has been done in the mesh generator, deformation profile optimization should only be used for problems which contain multiple deforming objects

Applicable simulation types: Isothermal Deformation

Non-Isothermal Deformation

RELATED TOPICS

Inter-object contact

DEMAX

DEMAX MaxStrainStep

OPERAND DESCRIPTION DEFAULT

MaxStrainStep Maximum strain at an element center per step 0.1

If MaxStrainStep = 0, DEMAX will not be used as a step size parameter

The time steps initiated by DEMAX will be recorded in the DEFORM database only if STPDEF is specified as "System" mode This value is typically 01 to 03 Applicable simulation types: Isothermal Deformation

OPERAND DESCRIPTION DEFAULT

Object Object number None

Ndata Number of element/density data pairs None

DefDensity Default relative density of all elements not listed in 1.0

the element/density data pairs

Element(i) Element number of ith data pair None

Density(i) Relative density of ith data pair 1.0

If no value is specified for DefDensity, it is assumed to be 1.0

The flow stress of porous objects should be specified for the fully dense material Applicable object types: Porous

DIEGEO Surface Geometry Page 1 of 4

DIEGEO Object, Gtype, Npoints, Npoly

= 1 Polygon description

= 2 Point description

= 3 Cross section(2D XYR format)

DEFINITION

DIEGEO specifies the boundary geometry of an object

REMARKS

DIEGEO boundary geometry may be used to specify a geometric profile of a rigid object or to define the

object geometry for automatic mesh generation.

DIEGEO information is described by a list of points and the connectivity of those points by three or four

node polygons Polygon description is selected by specifying a Gtype of 1 The order in which the

polygon ’s points are defined are displayed in the following figures.

DIEGEO Surface Geometry Page 2 of 4

Npoints is the number of points in the list which are used in the objects definition This is followed by a

list of 1 to Npoints of X, Y, and Z coordinates for each point.

listing of all polygons defining the object’s surface For three node polygons, the Point4(i) will be a repeat

DIEGEO Rotational Surface Geometry Page 3 of 4

DIEGEO Object, Gtype, Npoints

= 1 Polygon description

= 2 Point description

= 3 Cross section(2D XYR format)

DEFINITION

DIEGEO specifies the boundary geometry of an object rotated about CNTRAX

REMARKS

DIEGEO boundary geometry may be used to specify a geometric profile of a rigid object

DIEGEO information is described by a list of points For Gtype equal to 2, a point description is selected

By defining a CNTRAX which lies in the same plane as the list of Point(i), the object’s geometry is

defined by rotating the cross section around CNTRAX.

Npoints is the number of points in the list which are used in the objects definition This is followed by a

list of 1 to Npoints of X, Y, and Z coordinates for each point.

The profile geometry must be continuous, but does not need to represent a closed curve.

If the geometry is a closed curve, the data should be ordered counterclockwise If the geometry is not a closed curve, the geometry should be ordered counterclockwise such that the rigid object interior lies to the left of the profile geometry as would be the case if the entire closed shape had been drawn Lines of

symmetry should lie on either the global X or Y axis.

Applicable object types: Rigid, Elastic, Elastoplastic, Porous

DIEGEO Rotational Cross Section Geometry Page 4 of 4

DIEGEO Object, Gtype, Npoints, Npoints1

= 1 Polygon description

= 2 Point description

= 3 Cross section(2D XYR format)

DEFINITION

DIEGEO specifies the boundary geometry of an object in 2D XYR format

REMARKS

DIEGEO boundary geometry may be used to specify a cross section of a object

DIEGEO information is described by a list of points

Npoints is the number of points in the list which are used in the objects definition plus 2

Npoints1 is one rotational center and one rotaional axis, it equals 2

For Gtype equal to 3, 1st line is rotational center(X,Y,Z).

For Gtype equal to 3, 2nd line is rotational axis(X,Y,Z).

From 3rd line, followed by a list of 1 to Npoints-2 of X, Y, and R coordinates for each point

EXAMPLE

DIEGEO 1 3 9 2

1 1.0000000E-01 2.0000000E-01 3.0000000E-01

2 4.0000000E-01 5.0000000E-01 6.0000000E-01

3 2.2000000E+00 3.4628230E+00 0.0000000E+00

4 3.0000000E-01 3.4628230E+00 0.0000000E+00

5 3.6704000E-01 2.8956030E+00 0.0000000E+00

6 4.2897730E-01 2.3715000E+00 7.4999300E-01

7 9.4322000E-01 2.2528330E+00 0.0000000E+00

8 2.2000000E+00 1.9628230E+00 0.0000000E+00

9 2.2000000E+00 3.4628230E+00 0.0000000E+00

Applicable object types: Rigid, Elastic, Elastoplastic, Porous, Plastic

DIFCOE

DIFCOE matr, type, (value) or (N1, N2, npt, ndim)

Temp(1)…Temp(Ndata) or Atom(1) …Atom (Ndata)

Atom(1) …Atom(Ndata) C1(1) …C1(Ndata)

DIFCOE(1) …DIFCOE(Ndata) C2(1) …C2(Ndata)

DIFCOE(1) …DIFCOE(Ndata)

OPERAND DESCRIPTION DEFAULT

Matr Material Type NONE

Type =0 constant NONE

=1 f(A,T) NONE

=2 exponential function (=C1(T)exp((C2(T)*A)) NONE

=3 exponential function (=C1(A)exp((C2(A)/T)) NONE

N1 Number of temperature for matrix

N2 Number of carbon content (atom) for matrix

Npt number of temperature/atom points NONE

Ndim dimension of array (can not be changed) 3

Type 1 Example for Material 1

DPLEN

DPLEN edge length %

DEFINITION

DPLEN determines whether substepping should occur based on a simple calculation A time step size

is calculated for each surface node by,

The default value is of 0.5 is a reasonable value for most forming processes A value of 0 turns the substepping off

DRMESH

DRMESH Object, Ndata, DefXDisp, DefYDisp, DefZDisp

Node(1), XDisp(1), YDisp(1 , ZDisp(1)

: : : :

Node(Ndata), XDisp(Ndata), YDisp(Ndata) ZDisp(Ndata)

OPERAND DESCRIPTION DEFAULT

Object Object number None

Ndata Number of node/displacement sets None

DefXDisp Default nodal displacement in X of all nodes not 0.0

listed in the node/displacement sets

DefYDisp Default nodal displacement in Y of all nodes not 0.0

listed in the node/displacement sets

DefZDisp Default nodal displacement in Z of all nodes not 0.0

listed in the node/displacement sets

Node(i) Node number of ith data set None

XDisp(i) Displacement in X of ith data set 0.0

YDisp(i) Displacement in Y of ith data set 0.0

ZDisp(i) Displacement in Z of ith data set 0.0

DRZ

listed in the node/displacement sets

listed in the node/displacement sets

listed in the node/displacement sets

DEFINITION

DRZ is a boundary constraint used to apply a shrink fit to an object boundary

REMARKS

Xdisp(i), Ydisp(i), or Zdisp(i) should specify the amount of shrink fit interference.

The interference can be applied in the global X, Y, or Z direction The sign of the interference value (positive or negative) should indicate the direction of displacement occurring between the pre-assembly and post-assembly geometry of the constrained object.

The shrink fit constraint should be assigned to the interface contact nodes of either of the contacting objects, but should not be assigned to both.

Shrink fit constraints can only be applied to elastic objects.

If no value is specified for DefXDisp DefYDisp, and/or DefZDisp they will be assumed to be zero.

Reference Figure 6.11 on page 6.72.

DSMAX

DSMAX MaxStrokeStep

OPERAND DESCRIPTION DEFAULT

MaxStrokeStep Maximum stroke of the primary object per time step 0.0

A non-zero value must be assigned to either DSMAX or DTMAX, but values

cannot be assigned to both

DSMAX and DTMAX are two of several parameters used to control the size of time steps Other keywords which effect time step size include: DEMAX, DVMAX, and SLDERR A new time step will be generated when the criteria specified in any

of these keywords has been satisfied Reference sections 6.3.2 and 6.3.2.1

Typically, the value of MaxStrokeStep should correspond to an average strain increment of about 0.01, i.e a one percent height reduction

If MaxStrokeStep = 0, DSMAX will not be used as a step size parameter

The time steps generated by DSMAX will be recorded in the DEFORM database Applicable simulation types: Isothermal Deformation

Non-Isothermal Deformation

RELATED TOPICS

Step parameters, Primary object

Keywords: DEMAX, DTMAX, DVMAX, SLDERR, STPDEF

DTMAX

DTMAX MaxTimeStep

OPERAND DESCRIPTION DEFAULT

MaxTimeStep Maximum elapsed process time per step None

DEFINITION

DTMAX limits the amount of elapsed process time in one time step A new time step will be initiated when the elapsed process time reaches MaxTimeStep

REMARKS

A non-zero value must be assigned to either DTMAX or DSMAX, but values

cannot be assigned to both

DTMAX and DSMAX are two of several parameters used to control the size of time steps Other keywords which effect time step size include: DEMAX, DVMAX, and SLDERR A new time step will be generated when the criteria specified in any

of these keywords has been satisfied

Typically, the value of MaxTimeStep should correspond to an average strain increment of about 0.01, i.e a one percent height reduction

If MaxTimeStep = 0, DTMAX will not be used as a step size parameter

MaxTimeStep2 is used for complex processes where a different time step is

needed for the secondary stage of the process For example, hydraulic press with

a dwell

Applicable simulation types: Isothermal Deformation

Non-Isothermal Deformation

Heat Transfer

RELATED TOPICS

Step parameters

Keywords: DSMAX, DEMAX, DVMAX, SLDERR, STPDEF

DTPMAX

MaxTempInc Maximum increment in temperature per step 0

t_min Minimum time step allowed for a solution step 0

t_max Maximum time step allowed for a solution step 0

DEFINITION

DTPMAX specifies the maximum temperature increment per time step in heat transfer calculation The time step calculated by DTPMAX will control the time step for deformation when STPDEF = 3

REMARKS

If DTPMAX = 0.0 then this option is ignored

If DTPMAX  0.0 and STPDEF  3 then DTPMAX controls when a solution will substep If the temperature change over a time step  t is greater than

MaxTempInc, the simulation will substep The substepping time ( tDTPMAX) will be determined by the equation:

where is the maximum temperature change of any node on an object over the time step  t The simulation will continue to substep until the original time step  t has been reached The substeps ( tDTPMAX) are bounded by the minimum time step value tmin and the time step  t, or

If DTPMAX  0.0 and STPDEF = 3 (Temperature) then the time steps will be defined solely through temperature changes in the objects The first time step ( t) will be defined by DSMAX/DTMAX Thereafter, each subsequent time step will be defined by the equation:

where the new step time will be  tDTPMAX and is the maximum temperature change of any node on an object over the previous time step The new time step ( tDTPMAX) is bounded by the minimum time step (tmin) and the maximum time step (tmax), or

DTSUB

DEFINITION

After either DSMAX or DTMAX is prescibed, the deformation simulation may be broken

into smaller substeps, depending on the assigned value of DTSUB.

REMARKS

For a default DTSUB = 0.0, the system will assign DTSUB = 0.01.

For DTSUB < 1.0:

Assuming a free surface node will contact the die in the time of "dtime" and of all

the "dtime" the minimum is "dtmn," if dtmn >= DTMAX, there will be no substepping

However, if "dtmn" is smaller than DTMAX, then a substep

will be added in the simulation Under this situation, not only the the node with

"dtime" = "dtmn" becomes a contact node, but also those nodes with

(dtime - dtmn)/(dtmn) < DTSUB

will be considered contact nodes in this substep.

For DTSUB = 1.0:

No substepping will be done even "dtmn" is smaller than DTMAX In addition, if nodal

separation occurs, the simulation will not be repeated and the simulation will move

to the next step.

When DTSUB = 1.0 is taken, the simulation will be sped up due to no substepping, but

at the expense of a little greater volume loss.

For DTSUB = 2.0:

Upon release of nodes, the step will be recomputed to give the most updated stress state for the body

In cases where DTSUB is not equal to zero, the previous contact condition is used to compute

the current stress state

Applicable simulation types: Isothermal Deformation

Non-Isothermal Deformation RELATED TOPICS

Step parameters

Keywords: DTMAX, DSMAX

DVMAX

DVMAX MaxElemVolStep, MaxObjVolStep

OPERAND DESCRIPTION DEFAULT

MaxElemVolStep Maximum element volume change per step 0.0

MaxObjVolStep Maximum object volume change per step 0.0

DEFINITION

DVMAX limits the amount of volume change that can occur in an individual

element or an object during one time step A new time step will be initiated when the volume change in any element reaches MaxElemVolStep or the volume

change in any object reaches MaxObjVolStep

REMARKS

DVMAX is one of several parameters used to control the size of time steps Other keywords which effect time step size include: DSMAX, DTMAX, DEMAX, and SLDERR A new time step will be generated when the criteria specified in any of these keywords has been satisfied

The MaxElemVolStep represents the maximum allowable volume change for each object (dVe/Ve), and the MaxObjVolStep represents the maximum allowable volume change for the whole object (dV/V) Where Ve is the volume of the

element at the beginning of the step, dVe is the amount of volume change at the end of the step V is the volume of the object at the beginning of the step, dV is the amount of volume change at the end of the step If MaxElemVolStep = 0, the parameters will not be used as a step size parameter If MaxObjVolStep = 0, the parameter will not be used as a step size parameter

The time steps initiated by DVMAX will be recorded in the DEFORM database only if STPDEF is specified as "System" mode

For example if only one percent volume loss was wanted after 100 steps, than one would divide the percent volume loss by the number of steps: 01/100 Thus the DVMAX would be 0.0001

Applicable simulation types: Isothermal Deformation