The Process definition page includes the basic setup of process parameters. It includes stamping speed, blank holding force, forming time, etc. The user may change process parameters according to the actual stamping condition. Moreover, the user may add or delete any process. The basic process setup interface is shown in Figure 8.3.59.
Figure 8.3.59 Process definition page
PROCESS LIST
On the left of the process definition page, all defined process names are listed in the window of Stages. The current process name is highlighted in the list. The user may click another process from the list to switch the current process. The default process is specified according to the defined process type. For example, if Single Action process is chosen, closing and drawing are created as the default process. There are also default settings for the basic parameters such as stamping speed, blank holding force, stamping time, etc. Usually, few parameters are modified.
ADD STEP
This function allows the
user to add a new step in the current setup. The user may click the Add button
to display the new step interface illustrated in Figure 8.3.60.
Figure 8.3.60 New process interface
NAME
Allows the user to name the current step. Default step names are step1,
step2, step3, etc. The user may define a unique name for each step for the ease
of identifying the process.
DEFAULT SETTING
Allows the user to select a default setting for the new step. In
default setting, the user may select the program default parameters for the new
step. Otherwise, the user may choose to use the parameters of any defined step.
USE SETTING OF STEP: New step adopts parameters of an existing
step. The user may select an existing process from the pull-down list.
USE DEFAULT SETTING: Uses
system default parameters to define a new step.
INSERT POSITION
The user
is allowed to insert a new stage before or after any
stage.
Note: The step position cannot be modified after inserting the step.
DELETE STEP
This function allows the user to remove the current step from setup. The user may select a step from the step list as the current step, followed by clicking the Delete button to display the dialog box illustrated in Figure 8.3.61. Click on the OK button to delete the current step, or the Cancel button to abort the delete operation.
Figure 8.3.61 Delete process dialog box
STEP NAME & TYPE
NAME
Displays name of the current step. The user may type in a new name in
the input data field of Name.
HYDRO
Allows the user to access Hydroforming functions when activated.
TOOL CONTROL
This function is used to control the action of tools define travel speed, blank holding force, travel curve, etc. in the current step. A typical tool control option is illustrated in Figure 8.3.62.
Figure 8.3.62 Tool Control Option
TOOLS
List all the defined tools.
ACTION & VALUE
This group lists all tool control options. Each tool can be controlled
by one of the following options: Non-active, Stationary, Velocity, Displacement,
Force and Pressure.
NON-ACTIVE
Defined tool is not used in this
stage.
STATIONARY
Defined tool is stationary in the
current stage.
VELOCITY
The motion of the defined tool is
controlled by a velocity curve in the current stage. The user may select one of
the standard velocity curve options: Trapezoidal, Sinusoidal, Sin.W-H, Triangular,
and Variable. The standard velocity curves are illustrated in Figure 8.3.63. The user may type in the peak velocity in
the data input field of selected tool. The default velocity of die for the drawing
process is set as
(a) TRAPEZOIDAL (b)
SINUSOIDAL
(c) SIN.W-H (d)
TRIANGULAR
Figure 8.3.63 Types of standard velocity curves
If the user-defined Variable curve
is chosen, an Edit button is activated to enable the
user to define travel curve using the Load Curve dialog box.
DISPLACEMENT
Tool travel of this stage is
controlled by displacement-time curve. The user clicks the Edit button to
create displacement-time curve. The procedure is similar to those described in
the velocity curve section.
FORCE
Force is applied to selected tool
of current stage in closure and/or drawing process. There are three types of
force control: Constant, vs. Time and vs. Displacement. If the constant force
option is chosen, a constant force value is required. For the variable force
options, the user clicks the Edit button to create force- time curve or
force-displacement curve.
This button is activated when
force control is selected. The user may use this function to limit the maximum
displacement of tools along their working directions. When the force is applied
on the binder ring, this function can prevent removal of the binder ring and
crushing of the blank due to insufficient or excessive binder force. After
clicking on this button, the user can set the corresponding parameters. The
interface is illustrated in Figure 8.3.64. The user can set the Upper bound and Lower
bound of rigid body stopper to constrain.
Figure 8.3.64 Rigid Body Stoppers dialog box
NON-ACTIVE: The rigid body stopper is non-active.
DISPLACEMENT: Defines the displacement limit of
this tool. The user may enter a constant or define the curve.
VELOCITY: Defines the velocity characteristic
of the tool. The user can select different types of curves or define curves. The
program will automatically convert it into displacement curve.
Buttons
show the initial letter, which indicate: no constraints,
only constrain upper bound, only constrain lower bound and constrain both.
Please
refer to *CONSTRAINED_RIGID_BODY_STOPPERS keyword in
LS-DYNA Keyword Manual for a detailed description.
PRESSURE
Applies pressure on the selected tool in the
current stage. The defined pressure curve is converted into a force curve
during output of decks.
USER DEFINED CURVE
In each setup, all the defined curves are managed by the curve editor. The user may create, import, edit the existing curve using the function provided in the Load Curve dialog box illustrated in Figure 8.3.65.
Figure 8.3.65 Edit Load Curve dialog box
IMPORT CURVE
Allows the user to import a file containing curve data. The extension of curve files is “.cur” or
“.csv”. The curve file is defined according to the standard LS-DYNA keyword
format.
A typical curve format is shown in
Figure 8.3.66.
Figure 8.3.66 Typical curve format
EXPORT CURVE
Allows the user to export current
curve to a text file with “.cur” or “.csv” extension. Click the Export button
to display the export curve dialog box, followed by typing in the name of file.
Then, click the Save button to store the file in the selected folder.
INPUT
This page displays data the points
of the current curve. If no curve is defined, the user may create a new curve
by entering point coordinates. The user may modify data points of an existing
curve using functions such as add, delete, insert and clear.
ADD: Allows the user to add a data point at the
end of curve. Click the Add button to create two empty input data fields which
are highlighted in yellow. Next, the user may key in data points in the input
data field, followed by hitting the Apply button to complete the operation.
INSERT: Allows the user to insert a data point after
current data point. Prior to clicking this button, the user may use the mouse
cursor to choose the current data point. The selected data point is highlighted
in yellow. Next, click the Insert button to create two empty input data fields,
followed by typing in the data point and hit the Apply button to complete the
operation.
DELETE: Allow s the user to remove the current data
point.
CLEAR ALL: Allows the user to clear all data points
in the current curve.
APPLY: The user may click the
Apply button after performing add or insert point operation. The curve is
refreshed and displayed in the curve display window.
FORMULA
This page allows the user to create curve using mathematic formula such
as simple, quadratic, cubic, and sin (cos). When defining FLC curve, the
Keeler’s empirical equation is used.
Figure 8.3.67 Formula Page
TYPE: Allows the user to select a type of formula
used to create a curve. Types of formula includes: Simple, Quadratic, Cubic,
Sin and Cos, etc.
INTERVAL: Allows the user to specify
interval of abscissa. Default value varies according to the type of selected
formula.
ABSCI-START: Allows the user to specify start
point of abscissa. Default value varies according to the type of selected
formula.
ABSCI-END: Allows the user to specify end
point of abscissa. Default value varies according to the type of selected
formula.
PARAMETER: Allows the user to input required
parameters for each formula. After a formula is chosen, the expression of the
formula is displayed in the interface. For example, expression of Quadratic formula
is: . To create quadratic curve, the
user must define parameters A, B, C and D.
APPLY: After defining parameters, the user may click
the Apply button to create curve. The created curves are displayed in the curve
display area, while data points of the curve are listed in the Input page.
OPERATION
This page allows the user to perform additional operation to the curve,
such as Translate, Scale and Negate.
Figure 8.3.68 Curve Operation
MODE: Defines the curve operation mode, including Scale,
Translate and Negate.
PARAMETER: The user
may input curve operation parameters in the input data field. For example, the
user needs to individually key in the scale factors for abscissa and ordinate
to scale or translate a curve. The user can only negate a curve on the Y-axis.
APPLY: After specifying operation parameters, the
user may click the Apply button to complete the operation and refresh the curve
displayed in the curve display area.
CLIPBOARD
This function allows the user to
temporarily save the current curve to the clipboard. The user may load the
curve saved in the clipboard into the current curve interface. The user may
also compare the curve in the clipboard and the current curve. The clipboard
interface is illustrated Figure 8.3.69.
Figure 8.3.69 Clipboard Interface
DELETE: Removes the selected
curves from clipboard.
CLEAR All: Removes
all data stored in clipboard.
RESTORE: Allows the user to select curves from the
clipboard and restore as the current curve. If current curve is defined, the
program will prompt the user to use the curve in the clipboard to overwrite the
current curve. The program displays a dialog box illustrated in Figure 8.3.70 to prompt the user for confirmation.
Figure 8.3.70 eta/DYNAFORM
Question dialog box
BACKUP: Copies the current curve to the curve clipboard.
The program automatically adds a copied curve in the clipboard. All curve
information in the clipboard is displayed.
NO.: ID number of curves in clipboard.
TYPE: Type of curve such as time curve,
stress-strain curve and FLC curve..
PNTS: Number of points on the curve.
STATUS: The user may control whether the curve in the
clipboard is displayed in the show curve area. If the option is selected, the
curve is displayed in gray in the curve display area (current curve is
displayed in blue).
Note: The curve data on the clipboard is not saved in database file. After the user exits eta/DYNAFORM, all curves in the clipboard are automatically removed.
TOOLBAR OF CURVE EDITOR
The tool bar is displayed at the top of the curve display area. The
user may operate the curves by using the functions provided in the tool bar.
Tool bar interface is illustrated in Figure 8.3.71.
Figure 8.3.71 Curve Tool Bar
INSERT POINT
This function allows the user to
insert a point on the curve. After clicking this button, the user may hover the
mouse cursor to the desired location on the curve and click the left mouse
button to insert a point.
MOVE POINT
This function allows the user to
move a point on the curve. After clicking this button, the user may place mouse
cursor on any location near the curve in the display area. The point that is
the closest to the cursor is highlighted with a small circle. The user clicks the
left mouse button to select the point and the circle is turned to red. The user
may click and drag the mouse to move the point to a desired location on the
curve display window. Release the left mouse button to place the point at the
new location. A typical move point operation is illustrated in Figure 8.3.72.
Figure 8.3.72 Move Points on the Curve
DELETE POINT
This function allows the user to
delete points on a curve. After clicking this button, the user may move the
cursor to a point on the curve and click the left mouse button to delete the
point from the curve.
UNDO
Allows the user to undo the previous
operation.
SHOW ALL POINTS
This function displays a small
circle on each point on the curve.
SHOW CURSOR LINE
This function allows the user to
show cursor line.
PAN
This function allows the user to
pan the curve in the curve display window.
ZOOM BY WINDOW
This function allows the user to
zoom in on the curve by window selection. After clicking this function, the
user needs to click and drag the left mouse button to define a rectangle region
in the curve display window. Release the mouse button to zoom in on the curve.
ZOOM BY DRAG
This function allows the user to
zoom the curve view by dragging the mouse. The user clicks the left mouse
button in the curve display window, holds the mouse button, and moves the mouse
downward to zoom out. Move the mouse upward to zoom in the curve.
FIT VIEW
This function is used to adjust
the view center and scale automatically to display the entire curve. Allows the
user to fit the entire curve in the curve display window.
DURATION
This function is used to control the duration of the current stage. The
duration interface is illustrated in Figure 8.3.73. The user may select one of the four methods
to define duration: Time, Travel, Closure and Until Home. Each of these four
methods has its own advantages and requirements for different forming stages.
The user may select an appropriate control method according to the requirement
of the current setup.
Figure 8.3.73 Define Closure
DURATION TYPE
The user
may select a control type from the Type pull-down menu.
TIME: Allows the user to define a time to control the
current stage calculation time. This method is usually used in hydroforming
simulation. The user may enter a time value in the input data field.
TRAVEL: Allows the
user to specify tool travel distance along the working direction. The user
needs to select a reference tool from the tool list illustrated in Figure 8.3.74. Then, define the
displacement of the tool along its working direction. The time of travel is
automatically computed by the program.
Figure 8.3.74 Travel control stage time
Note: The
working direction can be acting in either negative or positive direction of the
axis. It is possible to set a negative value to indicate the stage time is
controlled by the tool travel distance along the opposite direction of its
working direction. In Sheet Forming, working direction should be assigned for
all tools.
CLOSURE: Allows the
user to choose closure gap required to between two tools. The user needs to
select two reference tools from the tool list illustrated in Figure 8.3.75.
Figure
8.3.75 Closure control stage time
FULLY MATCH: This option should be selected
when the mesh of two selected tools are not created using physical offset. It
is not required for the tools created using physical offset.
GAP: Allows the user to specify the distance from
complete closure of the two selected tools to stop simulation of current stage.
The calculation time is based on the mesh of the two tools, hence blank
thickness has to be taken into account. If physical offset algorithm is chosen,
the blank thickness is defined as the gap to calculate the closure time.
Note: When using two tools’ closure option, one of the tools has to be stationary, while the other must be controlled by velocity/displacement.
UNTIL HOME: Facilitate
the movement of selected tool to home position. The user needs to select a moving tool from the
tool list as illustrated in Figure 8.3.76, or select <All> for all tools.
Note: If <All>
is selected, the program will automatically calculate the tool motion curve and
make all the tools with defined motion return to HOME position. This function
is mainly used for flanging of multiple tools simultaneously.
Figure 8.3.76 Until home
OUTPUT D3PLOT FILE CONTROL
This function allows the user to define the time interval for outputting
D3plot files. The D3plot files are output at equal time intervals by default. The
user may also insert some required special frames. Sheet Forming provides four
D3plot output control methods.
Note: The
special frames can only be inserted when the velocity or displacement of tools
are defined in this stage.
CONTROL TYPE
The four D3plot output control methods are: Total number, List from
start, List from end and Time interval.
Total number
After inputting the total number of frames, the
program automatically calculates the time interval and outputs it to the deck.
List from start
The user may specify the distance list between
tool and the start point to insert some special frames, as illustrated in Figure 8.3.77. The user may output special frames according to a
certain order. For example, if it is from 0 to 10 and the step is 2, then fames
will be output at 0, 2, 4, 6, 8, 10, all measured in millimetre unit.
Figure
8.3.77 Add special output frames
ADD: The user may click
this button to add special frames. After clicking this button, the program will
list the corresponding distance value in the textbox on the left side according
to the given conditions. If there are values in the textbox, the program will
insert or add the new value according to the conditions input by the user.
SET: After
inputting the given conditions, click this button to clear the values in the
textbox and replace with new values.
SORT: Sort the
distance value input by the user.
DEFAULT: Click
this button to show the default special frames.
OK: Save the current
setting result and exit the special frames setup dialog box.
CANCEL: Exit the setup
dialog box without saving the current setting.
List from end
The operation of this function is similar to
the one of List from start.
Time
interval
The user may directly input the time interval. The
program will output a frame result after reaching the specified incremental
time interval.
Note: The user
may directly enter the distance value in the textbox and press the Enter button
to confirm. After exiting this dialog box, the program will automatically
delete the illegal characters and manage the order of distance values.
After the user adds special frames,
the program shows the information about the added special frames on the main
interface of the current stage. An example is illustrated in Figure 8.3.78.
Figure 8.3.78 D3plot File of Special Output Time Point
HYDRO MECHANICAL
This function allows the user to set parameters for hydro mechanical forming. The user may select the Hydro Option illustrated in Figure 8.3.79.
Figure 8.3.79 Hydro Forming
HYDRO MECH. PARAMETERS
In Hydro mech. field illustrated in Figure 8.3.80, the user may specify internal fluid pressure vs. time curve, boundary and direction of
applied internal fluid pressure.
Figure 8.3.80 Hydro Mech. parameters setup
ABOVE: In press
coordinate system, fluid pressure is applied on the top of blank illustrated in
Figure 8.3.81.
Figure 8.3.81 Fluid pressure is applied on top of blank
BELOW:
In press coordinate system, fluid pressure is applied on the bottom of
blank illustrated in Figure 8.3.82.
Figure 8.3.82 Fluid pressure is applied on bottom of blank
BY
PRESSURE: Set up internal
fluid pressure vs. time curve. This parameter is essential in sheet hydro forming.
The user may click P = 0 button to key in values of
internal fluid pressure vs. time curve in the define dialog box illustrated in Figure 8.3.83.
Figure 8.3.83 Hydro Pressure-Time Curve Defines
CONSTANT: Define
fixed internal fluid pressure. The user may key in a constant fluid pressure in
the Pressure input data field.
CYCLE: Define
analysis cycle time of fluid pressure. By default, cycle is set as 200.
TIME VARIABLE: Define variable internal fluid
pressure. The user may click the Edit button to display the Load Curve
definition interface. For a detailed description of curve definition, refer to
Chapter 14.
MASK: Assign boundary of applied fluid
pressure using closed loop line. Applied fluid pressure can be either inside or
outside of the boundary. By default, fluid pressure is applied on all blank
elements. Click the Entire button to display the Mask dialog box illustrated in
Figure 8.3.84.
Figure 8.3.84 Define fluid pressure boundary
INSIDE Apply
fluid pressure inside of the defined boundary line.
OUTSIDE Apply
fluid pressure outside of the defined boundary line.
PROJECTING DIRECTION: Allow the user to select project
direction. eta/DYNAFORM adopts one closed loop curve for the definition of
fluid pressure, hence it is not necessary to position the curve on top of
blank. The assigned curve is needed for projection onto the blank. Therefore,
the project direction for closed curve is required. After the user clicks this
button, the Direction definition dialog box is displayed. A detailed
description of this function is provided in Section 8.3.4.3. The default project direction is Z-axis of
the working coordinate system.
DX DY DZ: Display the coordinates of the
end point of project vector. Default vector starting point is the origin of working
LCS.
POINTS: Display
the number of points along curve.
LINES: The user may define region subjected to applied fluid pressure by defining
a closed loop curve. After clicking this button, the Select Line dialog box is
displayed.
POINTS: If no curve is provided in the database, the
user may define a closed loop curve by clicking this button to create a line
using points.
Note: When defining boundary of applied fluid pressure, it is recommended to select closed loop curve or a closed end point. If the curve/point is not closed, the program automatically closes curve and point.
CLEAR: Remove current
defined line. The program displays a confirmation dialog box illustrated in Figure 8.3.85.
Figure 8.3.85 Confirmation dialog box
OK: Accepts the current
setup and exits the dialog box.
CANCEL: Aborts the current
setup and exits the dialog box.
If the region subjected to applied fluid pressure is defined, the
Partial is displayed on the button next to Mask. This indicates that only some
of elements on the blank are subjected to applied fluid pressure.
SINGLE POINT CONSTRAINTS (SPCs)
This function allows the user to define single point constraint. Click
on the SPCs(0) button to display the dialog box
as shown in Figure 8.3.86. The user should select the constraint type
prior to clicking the New button to apply constraint to selected nodes. The
node IDs with defined constraint are listed in the box illustrated in Figure 8.3.86. The highlighted node with defined constraint is
marked on the display screen. The currently selected constraint node is marked
with angular brackets.
Figure 8.3.86 Single Point Constraints dialog box
The types of constraint include:
All: Constrain all the degrees of
freedom.
Hinged (UVW): Hinged constraint. Constrain
translation of all directions.
GuideW (UV): Constrain
translation along U and V direction.
GuideV (UW): Constrain translation along U and
W direction.
GuideU (VW): Constrain
translation along V and W direction.
PlaneVW (U): Constrain
part motion on VW-Plane only.
PlaneWU (V): Constrain part motion on WU-Plane
only.
PlaneUV (W): Constrain part motion on UV-Plane
only
SymUW (Vuw): Define part symmetry about UW-Plane.
SymVW (Uvw): Define part symmetry about VW-Plane.
User defined: Allow the user to customize
constraints.
If User defined option is selected, the user can toggle on any checkbox
combination to define translation and/or rotation constraints. U, V and W
indicate translation constraints in X, Y and Z, respectively. u, v and w
indicate rotation constraints in X, Y and Z, respectively.
T: Translation
constraints.
R: Rotation constrains.
NEW: Select
nodes.
MODIFY: Modify constraint type after
selecting constraint points.
DELETE: Delete the selected constraints.
DELETE ALL: Delete
all constraints.
OK: Accept
defined constraints and exit SPCs dialog box.
CANCEL: Reject
defined constraints and exit SPCs dialog box.