Blank Tool : Options and Results

Access: Open this function from one of the following locations:

  • Select Die Design > Blanking Tools > Blank from the menu bar.

  • Select Blank from the followingDie Design Guide: Die Process Design Guide (Forming).

Create or edit the blank for the electrode, using finite element analysis (FEA).

This function uses a finite element enginefinite element engine for blanking a set of adjacent (stitched) faces and creating a flat wire-body. This includes selecting which faces to create a wire body result for, defining the required parameters, defining the fixed boundaries, and transferring entities.

The Finite Element Analysis (FEA) engine used in the DieDesign application is based on technology supplied by the Forming Technologies Inc (FTI) 3rd party engine. For additional information on FTI, see www.forming.com.

The finite element engine is used in the following functions:

Whenever the finite element engine is used, resultant forces are calculated and stored for usage in the Die Forces operation.

Force Calculation: The force calculation employed depends on the type of operation being calculated. For additional information and to define some of the values used in force calculations, see the Die Force Calculation Preferences.

Correction Factor: A Die Preference option enables the setting of a default Correction Factor to manipulate forces calculated by the finite element engine. The forces displayed in the above mentioned functions will be multiplied by this factor.

The result is based on a list of parameters such as material type, thickness, some 2D boundary conditions, and more.

Required Step 1

  1. Pick the faces to blank and <exit><exit>(middle mouse button). The toggle option Smooth Chain Selection - On / Smooth Chain Selection - Off is displayed:

    Smooth Chain Selection - On: the system automatically identifies (and selects) all adjacent smooth faces. Deselect faces if required.

    Smooth Chain Selection - Off: only the picked faces are marked as selected.

 

 

Required Step 2

  1. Set the parameters, define the material side.

    Some of these parameters appear in the following DieDesign functions:

    These common parameters are:

    Material Type

    From the Material Type dropdown list, select the required material provided by the finite element engine.

    The materials displayed in this list have been entered into the Material Database. The Material Standard that is used is displayed in brackets next to the Material Type parameter name.

    Materials that are defined in the selected regional standard are shown in blue. Other (generic) materials (which have no name in the defined standard) are shown in gray.

     

    Thickness

    Enter the required thickness of the sheet metal in the relevant field. The default value is derived from the Die Setup. However, you can change this value according to your requirements.

    Neutral Fiber

    This is a toggle option Neutral Fiber / Selected Skin:

    Neutral Fiber

    Select this option to offset the skin.

    Selected Skin

    Select this option to perform the operation without offsetting the skin.

    Bending Type - Form

    This is a toggle option Bending Type - Form / Bending Type - Draw:

    Bending Type - Form

    Select the Bending Type - FormBending Type - Form option to form the bending type.

    Form Die

    When forming a part using a Form Die (illustrated below) use the Form Die forming process. This process is typically used in progressive dies and simple flanging operations.

    In this type of operation, the blank material is not pulled through a radius, it is simply bent around it. As a result, there are no additional strains produced by friction.

    Bending Type - Draw

    Select the Bending Type - DrawBending Type - Draw option to draw the bending type.

    Draw Die

    When forming a part using draw die (as illustrated below), it is recommended to use the Draw Die forming process. As  material passes over the radius on the die, additional strain is added to the part due to the friction between the part and the die and the bending and unbending process. These additional strains are not present when a part is manufactured using a form die.

    The friction and bending effects are automatically considered by Forming Suite when the Draw Die setting is turned on.  The Draw Die process formulation determines the areas of curvature on the part and adds the required forces and strains to any material that would flow over them during forming.


     

    Note: when applying bend lines manually, the Draw Die process should not be used.

    Normal Accuracy

    Select this option to create the blank at a regular accuracy level. The dropdown list displays the Low Accuracy and High Accuracy options.

    In addition to the above parameters, the following parameters also appear in the Blank function:

    Simplify Edges Tol.

    Enter the required Simplify Edges Tolerance value. In this case the system attempts to create analytical geometry within the specified tolerance, that is defined here.

    Create Blank

    This is a toggle option - Create Blank / Create Analysis Data. Select Create Blank to create the blankblank or toggle to Create Analysis Data (the analysis can also be activated from the Optional Step 3, Show Analysis Results).

    If the Blank function is used on a forming shape, an additional toggle option is displayed, Create New Part / Create a Feature in the Active Part:

    or

    Create New Part

    Create a new part in the forming shape. An additional  parameter is displayed enabling you to define the file name of the part.

    Create a Feature in the Active Part

    Instead of creating a new part, this option enables you to create a new feature in the active part.

     

    Note: If required you can click the blue arrow to change the direction of the blank operation.

  2. ExitExit(middle mouse button) the step.

Optional Step 1

  1. Define the forming conditions. The following parameters are displayed:

Constrained Edge

Define the forming condition. Different forming conditions can change the forming behavior of the stamped part, and therefore the following may be dramatically affected: Blank Shape, Formability Analysis (springback and safety zone), and Forces.

The various constraint options are displayed in a dropdown list.

The list of constraint options:

When a constraint is defined, a check mark is displayed adjacent to the relevant constraint type, as shown below.

The following forming conditions appear in the dropdown list:

Constrained Edge

Define fixed boundaries.

The following parameters are displayed:

From the dropdown list, select the required X and Y constraint type.

Pick edge(s) or point(s) to define the boundary constraints. The picked entity must lie on the boundary of the highlighted faces. The example below shows mixed constraints defined, with labels to identify the type of constraint. Labels are only displayed for mixed constraints.
Example:Example:

 

Pressure Pad

The pressure pad forming condition is used to simulate the effects of a pressure applied to an area of the blank inside the die. Pressure pads are typically applied to a flat surface or a surface that is coincident with the stripper and roughly normal to the press direction.

A pressure pad is used, among other reasons, to prevent twisting of the blank.
Example:Example:

In this example, the blue blank is the result of using fixed constraints (in the Constrained Edge or Constrained Face options); the blank is twisted. The red blank is the result of using a pressure pad; no twisting.

Pick the faces that the pressure pad will be applied to and define the force.

The following parameters are displayed:

Global Force:The following parameters are displayed:

Local Force: The following parameters are displayed:

Pick faces for the pressure pad and define the force.

Global Force

This is a toggle option Global Force / Local Force that enables you to define whether the same force is applied globally or different forces can be applied locally.

Global Force

The same force is applied globally. One pressure/force dialog is available for all selected faces, see below.
Example:Example:

 

Local Force

Different forces can be applied locally. A separate pressure/force dialog is available for each selected face, see below.
Example:Example:

 

 

Units = Mpa

A dropdown list showing the units of pressure. The selected unit is displayed in the pressure/force dialog, see below.

Note: 1 Mpa = 145.03773780 PSI.

Units = KN

A dropdown list showing the units of force. The selected unit is displayed in the pressure/force dialog, see below.

Notes:

  • 1 KN = 0.10197214 Tons (metric)

  • 1 KN = 0.11240451 Tons (short – US)

  • 1 KN = 0.10036117 Tons (long – UK)

  • 1 KN = 224.80902473 Lbf

Pressure/Force dialog

The pressure and force dialog. Either one or multiple dialogs are displayed.

Slider

The slider causes a linear change in the Pressure and Force values. The following are the default (fixed) values for the slider:

  • Low = 34.9986 KN
  • Med = 152.4983 KN
  • High = 269.9981 KN

Pressure

This shows the force in the displayed units (see Units = Mpa, above). The pressure is the Force / Area of selected faces.

If no face is selected, the pressure field displays a value of 0 and is dimmed.

Force

This shows the force in the displayed units (see Units = KN, above). The force value can by larger or smaller than the max./min. slider values.

  • Min. >= 0
  • Max. unlimited

Notes:

  • The slider position, pressure and force values are synchronized. This means that when changing one of the values (or slider) the other values will be updated automatically.

  • When adding/removing faces, the force value is kept and pressure value is updated.

  • At least 1 face is required to be selected.

Draw Bead

The draw bead forming condition is used to simulate the control of material flow into the die cavity using a draw bead or a lock bead. This essentially slows down the flow of material in a specific area. Edges/Composite are used to define the draw bead center line.
Example:Example:

In this example, the purple blank shape is the result or not using "Draw Bead" and the blue blank shape is the result when "Draw Bead" is defined on the straight blue lines.

The following parameters are displayed:

Global Tension:The following parameters are displayed:

Local Tension: The following parameters are displayed:

Pick wire(s) and define the tension.

Global Tension

This is a toggle option Global Tension/ Local Tension that enables you to define whether the same tension is applied globally or different tensions can be applied locally.

Global Tension

The same tension is applied globally. One tension dialog is available for all selected wires, see below.
Example:Example:

 

Local Tension

Different tensions can be applied locally. A separate tension dialog is available for each selected wire, see below.
Example:Example:

 

 

"tension dialog"

The tension dialog. As mentioned for Global/Local Tension above, either one or multiple dialogs are displayed.

Slider

The slider causes a linear change in the Pressure and Force values. The following are the default (fixed) values for the slider:

Low = 333.688 N/mm

Med = 444.917 N/mm

High = 556.146 N/mm

Tension

This shows the tension in the displayed units. The tension value can by larger or smaller than the max./min. slider values.

Min. >= 0

Max. unlimited

Notes:

  • The slider position and tension value are synchronized. This means that when changing the value (or slider) the other will be updated automatically.

  • At least 1 wire is required to be selected.

 

Blank Holder Force

Blank Holder Force (BHF) (or Edge Tensile) is used to get an accurate blank size before the tool is designed.

The tool contains the part faces and also addendum faces (also called "Runoff" faces or "Die" faces). In the image below, the purple faces are the addendum faces.
Example:Example:

By using BHF you do not have to create the addendum (runoff) surfaces and apply pressure (pad), so it is a much more convenient way to apply a processing condition without surface modeling. This is especially good for cost estimators and early analysis prior to tooling.

Instead of creating the addendum surfaces, you can simulate the presence of this extra material by applying a BHF to the perimeter of the part. The BHF applies a tension force to the edge of the part that can be used to simulate the effect of the restraint applied by extra addendum and binder material.
Example:Example:

The following parameters are displayed:

Blank Holder - On:The following parameters are displayed:

Blank Holder - Off: The following parameters are displayed:

Define the force.

Blank Holder - On

This is a toggle option Blank Holder - On/ Blank Holder - Off that enables you to define whether or not to define a blank holder.

Blank Holder - On

Define a blank holder. The boundaries are automatically selected.
Example:Example:

 

Blank Holder - Off

Don't define a blank holder. Blank Holder parameters are not displayed.
Example:Example:

 

 

Units = KN

A dropdown list showing the units of force. The selected unit is displayed in the pressure/force dialog, see below.

This parameter also appears in the Pressure Pad option, above. See the Pressure Pad option for the KN equivalences in the other forces.

"force dialog"

The force dialog. As mentioned for Global/Local Tension above, either one or multiple dialogs are displayed.

Slider

The slider causes a linear change in the Tension value. The Low, Med and High force values are based on the Max. Blank Holder Force (MBHF) and this depends on the following variables:

  • Material Thickness

  • Outer boundary length

  • Ultimate Stress – depends on material used.

The following are the default (fixed) values for the slider:

Low = 0.1 + MBHF

Med = 0.35 + MBHF

High = 0.6 + MBHF

Tension

This shows the tension in the displayed units. The tension value can by larger or smaller than the max./min. slider values.

Min. >= 0

Max. unlimited

Notes:

  • The slider position and force value are synchronized. This means that when changing the value (or slider) the other will be updated automatically.

  • At least 1 wire is required to be selected.

 

Constrained Face

Define fixed faces.

The following parameters are displayed:

From the dropdown list, select the required X and Y constraint type.

Pick face(s) to define fixity conditions. The example below shows mixed constraints defined, with labels to identify the type of constraint. Labels are only displayed for mixed constraints.
Example:Example:

 

Clear All Constraints

Clear all constraints from the display. If no constraints have been defined, this parameter is dimmed.

Optional Step 2

  1. Pick additional entities to be transferred or pick point(s) that lie on the highlighted faces.

    In this example, the following edges were selected, using the Filter Edges and Curves button:

Optional Step 3 :

Show the analysis results. This step is identical to the appropriate options in the Show Analysis function.

 

Press OK or Apply in the Feature Guide to complete the function,

The entities that were selected in Optional Step 2 have been transferred to the blank shown above (marked in red).

When completed, the Blank feature will appear in the Feature Tree

Some functionality may be dependent on the product package. Contact your Reseller if you require a license.