Generate simulation input Generate simulation input Generate simulation input
All further inputs are defined in the Input generator. Open the Input generator:
Model > Input generator ... > Simulation type: Incremental > OK
Tools Tools Tools Tools Binder is marked in red on this page, because columns must be
defined.
Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks
Columns for binder: It is recommended to use Tool center
Blank Blank Blank
Blank Outline > Copy from... > Select curve (Fig. 3.5) > Bndry (Pre) 1 >
OK
This option on Blank page creates a blank outline which is identical to the part boundary (Fig. 3.4).
Fig. 3.5 Fig. 3.5 Fig. 3.5 Fig. 3.5
The menu Select curve shows all generated lines – here the part boundary should be selected to generate a blank boundary that is identical to the part boundary.
Edit the blank boundary now:
Outline > Edit ... > Curve editor (Fig. 3.6) > Global mod > Convex >
move slider to max. value (right side) > Expand: 40 > OK Fig. 3.6
Fig. 3.6 Fig. 3.6 Fig. 3.6
Settings on Global modGlobal modGlobal modGlobal mod in Curve editorCurve editorCurve editor–menuCurve editor Definition of a
Definition of a Definition of a Definition of a weld line weld line weld line
weld line On the Blank page, several modifications have to be made to define a tailor–welded blank. Weld lines are always added in lower section
Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks
Fig. 3.7 Fig. 3.7 Fig. 3.7 Fig. 3.7
Blank BlankBlank
Blank page: Add weld ...Add weld ...Add weld ... Add weld ...
Weld menu opens, for which inputs have to be completed.
Fig. 3.8 Fig. 3.8 Fig. 3.8 Fig. 3.8
WeldWeldWeld Weld menu
Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks
Options for generating a tailor–weld blank:
• Weld line: Position and orientation of the weld–line is defined here.
• Properties: These are the properties of one part of blank, which can be changed in comparison to the basic or refer-ence blank (At least one of these properties has to be changed.).
• Thickness: Thickness of the blank
• Material: Material of the blank
• Angle: Rolling direction
• Properties apply at: A right mouse button click on one of the blank regions, which are joined with the weld line, defines the region for which the new properties (i.e., thick-ness, material and angle) are valid.
Weld line > Input… > Curve editor > Define weld line with right mouse button (the start– and end points lie on the blank boundary)
> OK
Weld line is accepted (Fig. 3.1 – Weld line 1).
A weld line joins two different parts of a blank. Properties of one part of blank are already defined on Blank page. Properties for the other part of the blank have to be defined on the Weld page. In this example the thickness of the two halves is different (0.8 mm and 1 mm):
Properties > Thickness: 1 (Fig. 3.9) Fig. 3.9
Fig. 3.9 Fig. 3.9 Fig. 3.9
Definition of new thickness
Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks
Click > A right mouse button clicks on the blank region, for which the new properties are valid (right part) > OK
After pressing OK button, a dialog (Fig. 3.10) asks if the automatic tool offset should be calculated based on the average thickness.
Fig. 3.10 Fig. 3.10 Fig. 3.10 Fig. 3.10
Dialog to adjust automatically offset to average thickness OK – (on Tools page the offset is 0.9 =(0.8+1.0)/ 2) (Fig. 3.11).
Tools page – new offset is automatically used
Definition of a T–
Definition of a T–
Definition of a T–
Definition of a T–
Joint Joint Joint Joint To define a second weld line, select the Add weld ... button on the
Blank page again (Fig. 3.7). The Weld–menu appears again. Now the properties of the second weld line have to be completed.
Add weld ... on Blank page
Weld line > Input > Define weld line using right mouse button (start point lies on the first weld line and the end point lies on the blank boundary) (Fig. 3.1 – Weld line 2) > OK
Properties > Thickness: 2 (Fig. 3.12)
Click > A right mouse button click on the blank region, for which the new properties are valid > OK
Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks
Fig. 3.12Fig. 3.12 Fig. 3.12 Fig. 3.12
New thickness will be defined
Again the dialog appears which asks if the automatic offset should be calculated as the mathematical average of the three thickness val-ues (see Fig. 3.10)
OK – on Tools page the offset is 1.2667 – ((0.8 + 1 + 2) / 3) Definition of a
Definition of a Definition of a Definition of a closed weld line closed weld line closed weld line closed weld line (patch–work) (patch–work) (patch–work) (patch–work)
Menu to add a weld line Add weld ... on the Blank page
Weld line > Input > Define a closed weld line using the right mouse button (Fig. 3.1 – Weld line 3)
Properties > Material > Import ... > zste180bhZ_1.mat > OK (Fig.
3.13)
Click > A right mouse button click on the blank region, for which the new properties are valid (new material) > OK
Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks
Fig. 3.13 Fig. 3.13 Fig. 3.13 Fig. 3.13
The new material will be defined
Using this procedure, any number of weld lines can be defined for a simulation. After launching the simulation, AutoForm will create the blank and the properties of the defined areas can be examined.
This examination is not possible prior the launch of the simulation since (before the simulation) only the boundaries are defined and the blank does not exist yet.
Drawbead Drawbead Drawbead Drawbead
In AutoForm a drawbead is defined using only a bead center–line and not with the real bead–profile geometry. This line specifies the position of the drawbead. Furthermore a restraining force is speci-fied which depends on the real profile geometry.
It is also possible to use the geometry of the drawbead, but that is not recommended. Advantages of the drawbead model are:
• Simulation time is shorter, because the drawbead geome-try with its small radii does not need to be geometrically formed by the mesh (hence fewer elements are necessary).
• Changes or optimization of the drawbead position or drawbead force can be achieved easily and quickly within AutoForm directly. In contrast, changes to the real profile geometry of the drawbead have to be made in a CAD sys-tem which takes much more time and effort.
Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks
Fig. 3.14 Fig. 3.14 Fig. 3.14 Fig. 3.14
AutoForm now offers a Drawbead generator for the correlation of the real profile geometry of drawbeads and drawbead force. With the Drawbead generator the real geometry of the drawbead can be specified and the force factor is automatically calculated by Auto-Form. If the force factor is known, the Drawbead generator will determine the real geometry of the drawbead. Use of the Drawbead generator is described in Lesson 4.
To define a draw bead an additional page has to be added to the Input generator.
Add > Drawbead ... (Fig. 3.14) > Add drawbead > OK A new page is added to Input generator (Fig. 3.15).
Fig. 3.15 Fig. 3.15 Fig. 3.15 Fig. 3.15
Drawbead page (DrwbdsDrwbdsDrwbds)Drwbds
Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks
Functions for generating a drawbead:
• Name: Name of a drawbead can be specified.
• Tools: Tools are defined; drawbead is active when these tools are closed.
• Input ...: Position of drawbead line can be specified (Curve editor).
• Import ...: Drawbead line is imported from CAD.
• Copy from ...: Drawbead line is copied from an existing line. Base line and drawbead line are treated as different lines.
• Dependent ...: Drawbead line is created from an existing line. Drawbead line is a reference to the base line. This means only the base line can be changed and the depen-dent drawbead line will also change correspondingly.
• Position: Displacement of drawbead line in x–y plane
• Width: Width of a drawbead
• Forcefactor: Force factor of a drawbead Drwbds > Name: bead1 > Above: binder > Below: die
Drawbead line > Input ... > Define drawbead line using the right mouse button (Fig. 3.1 – bead 1) (For symmetrical parts drawbead lines should intersect the symmetry line) > OK
Width: 15 Forcefactor: Medium: 0.35
An additional page has to be opened on the Drwbds page to add a second drawbead. This can be done in the Input generator with the menu option:
Add > Drawbead ... > Add drawbead > OK or on Drwbds page using button
Add Drawbead ... (Fig. 3.15 left lower corner) > OK
A dialog asks if the new drawbead should be generated with parameters of an existing drawbead. Fig. 3.16 shows that parame-ters of bead1 are used. Only the drawbead line has to be specified for bead 2. All other input parameters are automatically taken from bead 1 (Fig. 3.17).
Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks
Fig. 3.16Fig. 3.16 Fig. 3.16 Fig. 3.16
Dialog asking for reference beads Fig. 3.17
Fig. 3.17 Fig. 3.17 Fig. 3.17
Only the line needs to be defined for the second bead
The position and length of the second drawbead line will be defined using existing part boundary (Bndry (Pre)1).
Drawbead line > Copy from ... > Select curve > Bndry (Pre) 1 (Fig.
3.18) > OK
Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks
Fig. 3.18 Fig. 3.18 Fig. 3.18 Fig. 3.18
Select curve Select curveSelect curve
Select curve–menu
The second drawbead line is modified:
Drawbead line > Edit ... > Curve editor > Global mod > Expand: 20
> Trim (Fig. 3.20) (Length of a drawbead will be defined. Start point is defined using the right mouse button (Fig. 3.21) and end point is defined using Shift – right mouse button (Fig. 3.22)) > OK
Fig. 3.19 Fig. 3.19 Fig. 3.19 Fig. 3.19
Drawbead line is expanded on the Global modGlobal modGlobal mod–page in Curve Global mod Curve Curve Curve editor–menu.
Fig. 3.20 Fig. 3.20 Fig. 3.20 Fig. 3.20
Trim TrimTrim
Trim page in Curve editorCurve editorCurve editorCurve editor–menu
Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks
Fig. 3.21Fig. 3.21 Fig. 3.21 Fig. 3.21
Start point of a drawbead line Fig. 3.22
Fig. 3.22 Fig. 3.22 Fig. 3.22
End point of a drawbead line Process
Process Process
Process Only inputs for process step gravity are missing on Process page (Fig. 3.23):
Process > gravity > Gravity: Downwards Tool control > die: Stationary
Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks
Fig. 3.23 Fig. 3.23 Fig. 3.23 Fig. 3.23
Definition of process step gravitygravitygravitygravity
Control – Input of numerical Parameter Control – Input of numerical ParameterControl – Input of numerical Parameter Control – Input of numerical Parameter WriteRestart > off (Fig. 3.24)
WriteRestart ON means that a restart file (*.rst) is created. This file contains all data that is necessary to restart the simulation from a particular time.
Restarts can be used to save time, e.g. for multi stage processes, the different forming processes can be simulated one after the other.
The disadvantage is the size of the *.rst file which requires greater disk space.
Taking into account the speed of AutoForm, the restart option is only useful for large parts (e.g. side panel, floor panel). In Lesson 8 (Multiple Step process and Starting from Restart File), this option is described in complete detail.
Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks Lesson 3: Drawbeads and Tailored Blanks
Fig. 3.24Fig. 3.24 Fig. 3.24 Fig. 3.24
Control Control Control
Control page of Input generator – WriteRestartWriteRestartWriteRestartWriteRestart disabled Following results variables are switched off on Rslts page:
Rslts > Contact distance above Rslts > Contact distance below Rslts > Curvature
Start of simulation Start of simulation Start of simulation Start of simulation
Job > Start simulation ... > Start job > Program: af_3.1 > Start File > Reopen …
Lesson 4: Drawbead generator Lesson 4: Drawbead generator Lesson 4: Drawbead generator Lesson 4: Drawbead generator
2. 4 2. 4 2. 4
2. 4 Lesson 4: Drawbead generator Lesson 4: Drawbead generator Lesson 4: Drawbead generator Lesson 4: Drawbead generator
This lesson describes in detail how the width, the force factor and the restraining forces of a drawbead are determined automatically. The values are determined in the Draw-bead generator and have to be input manually in the Input generator.
Drawbead generator calculates the values Width and Forcefactor for a defined drawbead. These are dependent on
• geometry of the drawbead,
• sheet thickness,
• friction,
• forming velocity and
• material
These two values have to be specified manually in the Input genera-tor (Drawbead page > Width and Forcefacgenera-tor).
Warning WarningWarning
Warning: The function is currently a Beta–Version. This is mainly due to insufficient comparisons between the results of Drawbead gen-erator and actual stampings at present.
First a simulation file has to be created to use the Drawbead genera-tor, as was done in previous lessons.
Open example simulation file in_lesson_04.sim:
File > Open ... > Select a file > in_lesson_04.sim > OK The drawbead generator is opened with
Model > Drawbead generator ...
Lesson 4: Drawbead generator Lesson 4: Drawbead generator Lesson 4: Drawbead generator Lesson 4: Drawbead generator
Fig. 4.1Fig. 4.1 Fig. 4.1 Fig. 4.1
Drawbead generator
First the name of the drawbead is necessary (Name:). This name has to be the same as the drawbead defined in the Input generator.
Then the type of drawbead has to be specified. The Drawbead gen-erator offers three options: drawbead, lock bead and lock step.
The drawbead type is specified with the buttons shown in Fig. 4.2.
Menu for selecting drawbead, lock bead or lock step
Lesson 4: Drawbead generator Lesson 4: Drawbead generator Lesson 4: Drawbead generator Lesson 4: Drawbead generator
Different geometrical parameters are necessary for the different drawbead types.