FORMING

Each forming stage consists of one of the following processes: Crash Form, Single Action, Double Action and Triple Action. There are of six basic setup pages in each forming stage. Description of each pages are listed in the following sections.

 

8.2.4.1       GENERAL

The General page enables the user to define information such as Title and Working coordinate system for the current stage. A typical General page is illustrated in Figure 8.2.14.

 

Figure 8.2.14  A typical General page

 

TITLE

This function allows the user to key in the title for each forming stage. For multi-stage stamping simulation, the user can define different titles for each stage.

 

WORKING COORDINATE SYSTEM

This function allows user to set the working coordinate system for each stage. Auto Setup supports arbitrary stamping direction. Default working coordinate system is set as Global Z direction. The user may choose a CS from the list of coordinate system as Working Coordinate System of the current stage, or click on Select button to select from the display screen. If local stamping direction is needed, the user can click New button to define LCS for the current stage. The local W direction is chosen as the stamping direction. The newly created LCS will be automatically set as the working CS of the current stage. Refer to Section 2.5 for description about creating LCS.

 

8.2.4.2       BLANK

In Blank page, the user can define Part, Material, Thickness and Property of blank. Furthermore, the user may define weld line for tailor-welded blank application, contact interface for laminated sheets and symmetry condition. The interface of Blank page is illustrated in Figure 8.2.15.

Figure 8.2.15  Interface of Blank Page

GEOMETRY

 

PARTS

As shown in Figure 8.2.16, the Part field allows the user to assign a part as blank for stamping simulation. After clicking the Define geometry… button, the DEFINE GEOMETRY dialog box illustrated in Figure 8.2.17 is displayed.

 

Figure 8.2.16  Geometry field

 

Figure 8.2.17  Define Geometry dialog box

 

ADD PART…: This function allows user to define blank by selecting one or more parts from the part list. Once selected, the parts are highlighted on the screen, as well as in the Parts List of SELECT PART dialog box.

 

REMOVE PART: This function allows the user to remove selected parts from the part list.

 

ADD ELEM…: This function allows the user to add selected elements as blank.

 

COPY ELEM…: This function allows the user to copy or offset elements from existing elements. The elements will be added to a new part, which is then defined as blank.

 

SPLIT PART: This function allows user to split the blank into several blanks. Different material, thickness and properties can be assigned to each blank. The user can easily generate the blanks for stamping simulation using tailor-welded blank.

 

DISPLAY: This function allows the user to display all the parts which are defined as blank. The user may easily check and repair the blank mesh without displaying other parts on the screen.

EXIT: This function allows the user to dismiss the DEFINE GEOMETRY dialog box.

 

After blank parts are defined, the names of each part are displayed in the Part field illustrated in Figure 8.2.19. The default material, thickness and property are assigned for the part. The user may reassign material, thickness and property for each part.

 

MATERIAL

The Auto Setup defines a default type 36 material for blank part. The user may click  button under Material to modify or create a material. After clicking the button, the Material window illustrated in Figure 8.2.18 is displayed.

 

Figure 8.2.18 Define material

NOTE: If no material is assigned to the Part, the BLANKMAT is listed in material button. After defining the material, the material name is displayed on the button.

 

Figure 8.2.19 Material Define dialog box

TYPE: Display defined material type. Auto Setup currently supports the following material types: 1, 4, 18, 24, 36, 37, 39, 64, 106 and 125.

 

NAME: Display the defined material name.

 

NEW…: Allow the user to create new blank material. After clicking this button, the list of material types illustrated in Figure 8.2.20 is displayed. The user may select one of the material types from the list. Once a material type is chosen, the MATERIAL dialog box illustrated in Figure 8.2.21 is displayed.

 

Figure 8.2.20 Select material type

Figure 8.2.21 Material dialog box

Forming Limit Curve (FLC): This parameter should be defined if material type 39 is chosen. If no FLC curve is defined, <NONE> is displayed at the FLC input field. To define FLC curve, click  button to display the FLC curve edit dialog box illustrated in Figure 8.2.22.

 

NOTE: The FLC curve defined in Auto Setup is represented in engineering strain.

In the FLC curve edit dialog box, the user may enter the FLC data points directly in INPUT page. Alternatively, the user may define FLC curve using KEELER’s FLC empirical equation provided in the FORMULA page. After entering the n and t values, click the APPLY button to generate the FLC. The FLC curve is displayed in the show curve interface illustrated in Figure 8.2.22. Detailed description of curve edit operation is provided in Section 8.4.6.5.

Figure 8.2.22 FLC Curve

 

EDIT…: Allow the user to edit the material parameters listed in the MATERIAL dialog box illustrated in Figure 8.2.23.

 

Figure 8.2.23 Material Edit dialog box

NOTE: Edit Material and Define Material dialog boxes are basically identical. The user may modify any parameter in the dialog box, except the material type. If the user needs to change the material type, he/she must create another the material properties.

 

IMPORT: Allow the user to import a material file. The extension of the file name is “.mat”. By default, Import Material window illustrated in Figure 8.2.24 is displayed when the button is hit.

 

NOTE: For PC users, the extension of material file may be associated with Microsoft Office Access. The “.mat” extension will not be displayed, but the extension of material files may be viewed from the console model. To display the “.mat” extension, the user must delete the association between the “.mat” extension and Microsoft Office Access.

 

import

Figure 8.2.24  Import Material window

 

After selecting a file, the user may click IMPORT button to import selected material and assign it to the selected blank part.

 

EXPORT: Allow the user to export and write the current material into a file. The file is saved with an extension “.mat”. The Export Material window is illustrated in Figure 8.2.25.

export

Figure 8.2.25  Export Material window

MATERIAL LIBRARY: This function enables the user to select the type of generic material library in eta/DYNAFORM. There are four types of generic material library supported by eta/DYNAFORM. They are United States, JAPAN, CHINA and EUROPE. The User Defined material library option is provided to enable users to build their own material library.

 

Figure 8.2.26 Material Library Standard

After selecting type of material library, the material library GUI illustrated in Figure 8.2.27 is displayed. The user proceeds by selecting type of material from library to be assigned as the blank material.

 

The Material Library interface allows the user to conveniently select a type of material. The right key menu enables the user to expand each node of tree structure. The number listed in the parentheses next to each material indicates the material type. The previously selected material type number will be displayed in the parentheses.

 

 

Note: The user-defined material is saved in the user-defined directory. The user can set the default path of material library from Option/Material Library menu.

 

Figure 8.2.27 GUI of Material Library

 

l User Defined

            This function allows the user to add, delete and rename the user-defined material library. The added material library will be shown in the list of material library. The User Defined Standard dialog box is illustrated in Figure 8.2.28.

            

ADD: Add and define the name of user-defined material library.

RENAME: Edit the name of user-defined material library.

DELETE: Remove the user-defined material library.

 

 

Figure 8.2.28 User Defined Standard dialog box

 

l

            This function allows the user to jump between the types of material model within the material strength level. If the material strength level is highlighted, the user can click the button to jump between the types of material strength level within the material category.

 

l Material Category

            Click right mouse button at the root node of tree structure to create a new material category, strength level and type of material. Default material categories are Steel and Aluminum. The user can assign name to the new material category, and rename or delete material category. As illustrated in Figure 8.2.29, the list of each node is displayed if the right mouse button is hit.

 

 

Figure 8.2.29  The corresponding list of each node

l Strength Level

            The material library allows the user to classify the following steel grades: Low, Medium, High, Advanced High, Hot Roll and Cold Roll. Users can easily manage their own material library.

 

l Material Name

            The user can click the right mouse button of Strength Level to define a new material. The Create Material dialog box illustrated in Figure 8.2.30 is displayed. The user can select material type and edit material parameters in this dialog box. The default material name is similar to its title. The user must specify the path of the new material prior to saving it.

 

Figure 8.2.30 Create Material dialog box

 

l Material Type

The user can click the right mouse button of Material Name to define or import the new material type. The user can also click right mouse button of Material Type to edit or delete material type. The Create Material Type dialog box is illustrated in Figure 8.2.31. After the material is imported, the type of material number is automatically assigned.

material

Figure 8.2.31  Import Material dialog box

 

THICKNESS

   By default, the thickness value for blank is defined in the New Simulation dialog box. The user can edit thickness of blank in Thickness field.

 

PROPERTY

   By default, the properties of blank are set as illustrated in Figure 8.2.32. These blank properties are good for most stamping simulation.

 

Figure 8.2.32  Define Blank Properties

 

ELEMENT FORMULATION: This option allows the user to choose type of element formulation. Currently, 16 shell element formulations are supported in eta/DYNAFORM. In addition, thick shell and solid element formulation are available. The default element formulation is No. 2 BELYSTSCHKO-TSAY shell element formulation. This element formulation is the most popular and economical one for sheet metal forming simulation. For springback analysis, it is recommended to select No. 16 Full Integration element formulation in both draw simulation and springback analysis.

 

 

NUMBER OF INTEGRATION POINTS: The default number of integration points is 5. Increasing through thickness integration points may improve the precision of simulation result. On the other hand, the simulation time will drastically increase. For draw simulation without considering springback, the default through thickness integration points is recommended. If there is draw forming simulation with subsequent springback analysis, through thickness integration points of 7 or greater is suggested.

 

OK: Save the current setting and exit Define Property dialog box.

DEFAULT: All parameters are restored to the default value.

CANCEL: Exit the dialog box without saving the modification of current setting.

 

POSITION

This function allows the user to move the position of blank along U, V and W direction illustrated in Figure 8.2.33. After auto positioning, the movement along W direction is listed in the Position field.

 

Figure 8.2.33 Position field

 

SYMMETRY

 

This function allows the user to create symmetry condition for the blank to reduce simulation time. The user may define either ½ or ¼ symmetrical condition along the line of symmetry of blank. ½ and ¼ blank mesh is required for applying ½ and ¼ symmetrical conditions, respectively. By default, None is displayed in the field of Symmetry type illustrated in Figure 8.2.34, indicating no symmetry condition is applied to blank. The user may click  button to display the SYMMETRY PLANE dialog box illustrated in Figure 8.2.34.

 

Figure 8.2.34  Symmetry field

1/2 SYMMETRY

This function allows the user to define ½ symmetrical blank. The interface is illustrated in Figure 8.2.35.

 

Figure 8.2.35 Define Symmetry Plane

 

SYMMETRY AXIS: The current user defined symmetry plane information is displayed in this field. The symmetry plane is specified by a point, a vector and WCS direction.

 

O(0,0): Indicate the coordinate of starting point of the vector defining symmetry plane.

 

X(1,0): Indicate either UW- or VW-plane chosen as symmetry plane.

 

UW-PLANE: A plane parallel to WCS’s UW plane is chosen as symmetry plane. The user specifies the location of plane by using Select Points function illustrated in Figure 8.2.36. The position of symmetry plane is displayed in O (X, Y), while the direction of symmetry is displayed in X (1, 0). A vector is displayed in WCS’s UW plane on the screen to show the symmetry plane. See Figure 8.2.36 for more details.

 

VW-PLANE: A plane parallel to WCS’s VW plane is chosen as symmetry plane. The user specifies the location of plane by using Select Points function illustrated in Figure 8.2.35. The position of symmetry plane is displayed in O (X, Y), while the direction of symmetry is displayed in X (0, 1).

 

2 POINTS ON UV-PLANE: Enable the user to define the vector of symmetry plane by selecting two points. The symmetry plane is parallel to W axis. The first point of the vector specifies the position of the symmetry plane.

 

SELECT POINT(S): Allow the user to select one or two points to specify symmetry plane. If the user selects UW-plane or VW-plane option, only one point is required to specify the location of symmetry plane. If the user selects 2-Points on UV-plane option, then two points are required to define symmetry plane.

 

TOLERANCE: Default tolerance is 0.01. Nodes fall inside the tolerance are defined with symmetry boundary condition. The user may increase tolerance to extend the search range for nodes on symmetry plane.

Figure 8.2.36 Define Symmetry

 

 

1/4 SYMMETRY

This function allows the user to apply symmetry boundary condition on ¼ symmetry blank. After defining a vector, another vector normal to the defined vector is automatically created to specify the other symmetry plane. Figure 8.2.37 illustrated a typical definition of ¼ symmetry planes.

Figure 8.2.37  Define 1/4 Symmetry

WELDS

 

The user can conveniently define tailor-welded and composite blanks. After multiple blank parts are defined, the Welds option is activated on Blank page illustrated in Figure 8.2.38. After the weld lines are defined, the information of weld lines is displayed in Welds list.

Figure 8.2.38  Define Tailor-welded Blank

 

ADD…

This function allows the user to select adjacent nodes to define weld element. After clicking this button, the DEFINE BLANK WELD dialog box illustrated in Figure 8.2.39 is displayed.

 

NOTE: In LS-DYNA, the pairing nodes of weld must consist of two separate nodes with different positions. In order to reduce the preparation time, eta/DYNAFORM will automatically separate the identical nodes which are used to define the weld. User only needs to add the corresponding elements to different parts.

 

Figure 8.2.39  Define Weld dialog box

 

NODAL PAIRS: Display number of nodal pairs. After the user selecting nodal pairs, the number is displayed in the data box.

 

OVERLAP BLANK: The user needs to select this option for overlap blank. After selecting this option, the line connecting the nodal pair is normal to its connecting element.

 

WELD WIDTH: Specifies the width of weld. Default width is 1.0 (mm). If the distance between selected node pair is smaller than default value, weld is defined for the selected node pair. The user may adjust the width to include the node pairs with larger gap.

 

INPUT…: The user may click this button to select node pair. From the displayed SELECT NODE PAIR dialog box, select two rows of nodes required for definition of weld line. After selecting the nodes, weld as illustrated in Figure 8.2.40 is defined between nodal pairs.

Figure 8.2.40  Define Weld

As illustrated in Figure 8.2.41, the nodes are separated and automatically offset if only one row of nodes is available.

 

(a)                                        (b)

Figure 8.2.41  Offset Node    (a) Before       (b) After

 

DELETE: This button allows the user to remove all current node pairs.

 

FAILURE: The user may define failure criteria for the weld.

 

NEVER FAILURE: By default, the NEVER FAILURE option is chosen to ensure weld does not fail during the stamping simulation.

 

CONDITIONAL FAILURE: Allow the user to define conditional failure criteria and its relevant parameters. Detailed description is available in LS-DYNA User’s Manual.

 

EDIT

This function allows the user to edit the defined weld. The user may delete selected nodal pair, add new nodal pair, modify weld failure criteria, etc.

 

DELETE

After a weld line is defined, weld information such number of nodal pairs, failure criteria of weld is displayed in the weld list illustrated in Figure 8.2.42.  The user may delete a weld by clicking the Edit button, following by clicking the Delete button to remove the current weld definition.

 

Figure 8.2.42  Welds List

 

CONTACT

 

For overlap blanks, the user should define the contact interface between blank parts illustrated in Figure 8.2.43. The user may modify contact parameters, such as friction coef., contact coef. type, etc. for contact interface between blank parts. For tailor-welded blank, the user should toggle off the checkbox for the contact between the blank parts.

 

Figure 8.2.43  Define Contact Between Blanks

 

USE CONTACT BETWEEN BLANK PARTS

 

This option should be toggled on for overlap blanks.

 

ADVANCED…

The user may modify some contact parameters between blanks through advanced options illustrated in Figure 8.2.44.

 

contact

Figure 8.2.44  Define Advanced Contact Parameters

 

CONTACT TYPE: This function allows the user to select type of contact algorithm illustrated in Figure 8.2.45.

 

Figure 8.2.45 Define type of contact algorithm

 

STATIC FRICTION COEF: Allow the user to define static coefficient of friction. Default value is 0.125.

 

VISCOUS FRICTION COEF: Allow the user to define viscous coefficient of friction. Default value is 0.

 

VISCOUS DAMPING COEF: Allow the user to define viscous coefficient of damping. Default value is 20.0.

 

DYNAMIC FRICTION COEF: Allow the user to define dynamic coefficient if friction. Default value is 0.

 

DECAY COEF: Allow the user to define coefficient of decay. Default value is 0.

 

NORMAL FAILURE STRESS: Allow the user to define the normal failure stress.

 

SHEAR FAILURE STRESS: Allow the user to define the shear failure stress.

 

 

8.2.4.3       BOUNDARY CONDITION

This page allows the user to define single point constraints, acceleration time and advanced parameters for thermal analysis. The boundary condition interface is illustrated in Figure 8.2.46.

 

Figure 8.2.46  Boundary Condition page for draw simulation

 

SINGLE POINT CONSTRAINTS (SPCs)

 

This function allows the user to define single point constraint. Click on EDIT…button to display the dialog box as shown in Figure 8.2.47. The user should select the constraint type prior to clicking the SELECT… button to apply constraint to selected nodes. The node IDs with defined constraint are listed in the box illustrated in Figure 8.2.47. The highlighted node with defined constraint is marked with red label on the display screen. The currently selected constraint node is marked with angular brackets.

 

         

Figure 8.2.47 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):          Define part symmetry about VW plane.

PlaneWU (V):          Define part symmetry about WU plane.

PlaneUV (W):          Define part symmetry about UV plane.

User defined:           Allow the user to customize constraints.

 

If User defined option is selected, the user can toggle on any checkbox 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.

SELECT…:             Select nodes.

DELETE:                Delete 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.

 

In setup of multi stage forming simulation, the user may translate and/or rotate blank or transform coordinate in the subsequent stage using the Transformation function illustrated in Figure 8.2.48. It is recommended to perform rotation operation prior to the translation operation.

 

Figure 8.2.48  Define Boundary Condition

 

The user can click EDIT button on the Boundary Condition page to enter the Transformation dialog box illustrated in Figure 8.2.49. The added transformation operation is displayed in the list. The user can click the up or down arrow to adjust the sequence of transformation, or click DELETE button to delete the defined transformation.

ADD:                         Add translation, rotation or coordinate transformation operations.

EDIT:                        Edit the defined translation, rotation or coordinate transformation operations.

APPLY:                     Add the defined translation, rotation or coordinate transformation operations to the list.

 

TRANSLATION: Define distance and direction of translation. The user may define translation using three approaches:

 

            Enter the distance along U, V and W directions. The direction of translation and distance is automatically calculated according to the input. If DIRECTION button is hit, the direction of translation is displayed in the dialog box and marked with an arrow in the display screen. The distance is displayed in the DISTANCE field.

 

            ● Click on DIRECTION button to define direction of translation. Then, exit the DIRECTION dialog box and key in the desired distance in the data input field of DISTANCE. The direction of translation and distance is automatically calculated according to the input.

 

            Click on 2 Points/Nodes button, following by selecting two points/nodes from the display screen. The direction of translation and distance is automatically calculated according to the input.

 

ROTATION: Define rotation axis and angle. Rotate the model about any axis of current coordinate system with any input angle.

 

LCS2LCS:       Conversion of local coordinate system. The user is allowed to convert the model from one coordinate system to another. The translation and rotation information automatically output.

 

Figure 8.2.49 Transformation dialog box

TOOL ACCELERATION TIME

 

This function allows the user to specify the tool acceleration/ramp time from 0 to peak value. The ramp time should be defined to guarantee the stability of calculation. Default ramp time is 0.001 second, as shown in Figure 8.2.50.

 

Figure 8.2.50  Acceleration/ramp time

 

THERMAL ANALYSIS

 

If COUPLED THERMAL STRUCTURAL ANALYSIS option is selected, the ADVANCED… button (this option is toggled off by default) is toggled on. Click on ADVANCED… button to display THERMAL ANALYSIS dialog box illustrated in Figure 8.2.51. Refer to LS-DYNA User’s Manual for detailed description about parameters for coupled structure-thermal analysis.

 

Figure 8.2.51  Thermal Analysis interface

 

The Thermal Analysis interface enables the user to define parameters such as Material, Boundary, Contact and Control parameters, which are used to perform the steady and transient coupled structure-thermal analysis.

 

      Material

 

      In coupled structure-thermal analysis, the user must define thermal properties of sheet material, as well as tools.

 

          NEW: Click to select a thermal material model from the list illustrated in Figure 8.2.52. After the material is selected, the user may define the thermal material properties in the THERMAL MATERIAL dialog box illustrated in Figure 8.2.53.

 

Figure 8.2.52  Thermal material models

Figure 8.2.53 Thermal Material dialog box

 

          EDIT:                          Edit defined material parameters.

         

IMPORT:      Enable the user to import material from any material file with “.mat” extension. Select a material file, following by clicking OK button to close the IMPORT MATERIAL dialog box.

 

EXPORT:     Enable the user to save any defined material in the file with “.mat” extension. Click on Export…button to display the EXPORT MATERIAL dialog box.

 

      Boundary

    

      This page enables the user to define thermal boundary conditions such as initial temperature (blank and tools), radiation, convection and final temperature, as shown in Figure 8.2.54.

   

BLANK TEMPERATURE:      Set initial temperature for blank.

TOOLS TEMPERATURE:      Set initial temperature for tools.

RADIATION FACTOR:             Thermal radiation factor.

CURVE MULTIPLIER:            Curve multiplier. Click on the button to define a curve. The number of points on curve is displayed on the button.

HEAT TRANSFER COEF.:      Coefficient of heat transfer.

FINAL TEMPERATURE:        Final temperature.

Figure 8.2.54  Boundary page

 

      Contact

     

Contact page enables definition of thermal contact and friction, as shown in Figure 8.2.55.

 

THERMAL CONDUCTIVITY:        Thermal conductivity between gaps.

RADIATION FACTOR:                      Thermal radiation factor.

HEAT TRANSFER COEF.:               Coefficient of heat transfer for closed ring.

MIN. GAP:                                             The minimum gap. If the gap is smaller than MIN. GAP, use htc (heat transfer coefficient) value.

MAX. GAP:                                           The maximum gap. If the gap is greater than MAX. GAP, thermal contact does not occur.

CONTACT ALGORITHM:               Thermal contact algorithm.

THERMAL BOUNDARY CONDITIONS ARE OFF WHEN PARTS ARE IN CONTACT.

THERMAL FRICTION:                    Thermal friction factor. Curve defining the relation between dynamic/static coefficient of friction and temperature.

 

Figure 8.2.55 Contact page

      Control

 

      Control page illustrated in Figure 8.2.56 enables the user to define thermal control parameters. For thermal or coupled structure-thermal analysis, these control parameters are used to control the type of solver for steady or transient analysis, linear or nonlinear analysis and time step size for thermal analysis.

 

THERMAL ANALYSIS TYPE (ATYPE):

               0: steady analysis

               1: transient analysis

 

THERMAL PROBLEM TYPE (PTYPE):

               0: linear problem

               1 or 2: nonlinear problem. If chosen, please define

*CONTROL_THERMAL_NONLINEAR

 

TIME STEP CONTROL (TS):

               0: fixed time step

               1: variable time step

 

TIME INTEGRATION PARAMETER (TIP):

               0: set to 0.5 and use Crank-Nicholson scheme

               1: use fully-implicit scheme

 

MAX. MATRIX REFORMATIONS (REFMAX)

Figure 8.2.56  Control page

 

 

8.2.4.4       TOOLS

In the Tools definition page, the user may add and remove tools, adjust position between blank and tools, define tool properties, working direction and contact between blank and tools. The interface is illustrated in Figure 8.2.57.

Figure 8.2.57 Tools definition page

 

TOOL LIST

The list of tool names is displayed in the box on left hand of Tools definition page. The indented tool name button indicates the tool is working tool. In Auto Setup, default tools are set according to the selected process type. For example, if SINGLE ACTION process is chosen, default tools consist of die, punch and binder. Each basic parameter is set with default value, except for tool part, working direction, contact offset, etc. The user may directly define each tool from the menu page to saves time for defining tools.

 

NOTE: Undefined tool is labeled in red. In each setup, undefined parameters are labeled in red to remind the user that the setup is incomplete.

 

ADD TOOL

 

The ADD TOOL function allows the user to create a new tool in current setup. The user may click ADD button to switch the interface to the new tool interface illustrated in Figure 8.2.58.

 

Figure 8.2.58  New Tool interface

TOOL NAME

Allow the user to define a name for current tool. Default tool name is tool1, tool2, tool3, etc. The user may define a meaningful tool name as current tool for the ease of identifying each tool in the stamping simulation.

DEFAULT SETTING

Allow the user to set default setting for current tool such as working direction, offset, etc. There are two options in default setting. One is using existing tool as reference, which newly generated tool adopted the basic parameters of the reference tool. The other one is to set the default setting of basic parameters of the newly generated tool.

 

USER SETTING OF TOOL: New tool adopts basic parameters of an existing tool. The user may select an existing tool from the pull-down list.

 

USER DEFAULT SETTING: Use default parameters to define the new tool. The working direction of this tool is WCS +W direction.  Both contact offset and travel distance is equal to 0.

 

 

APPLY

Enable the user to generate new tool and list it in the tool list.

 

DELETE TOOL

 

This function allows the user to remove current tool from the setup. The user may select any tool from tool list as current tool, following by clicking the DELETE button. The DELETE TOOL dialog box illustrated in Figure 8.2.59 is displayed.

Figure 8.2.59 Delete Tool dialog box

 

Click OK to delete the current tool, or Cancel to quit the operation.

 

TOOL NAME

 

This function allows the user to modify current tool name. When creating a tool, the user may arbitrary assign a name for the tool. After the tool is generated, the user may edit the tool name listed in Tools definition page. In the input field of NAME, the user may key in new tool name and press “Enter [CR]” to complete the operation.

 

Note: Each tool must have a unique name. If the newly created tool has the same name with an existing tool in the setup, numerical number will be added at the end of new tool name, e.g. die 1, die 2, punch 1, punch 2, etc.

 

TOOL GEOMETRY

 

This function allows the user to assign parts in current tool. The user may add one or more parts in current tool. Click Define geometry button to display the DEFINE GEOMETRY dialog box illustrated in Figure 8.2.60.

Figure 8.2.60 Tool Define Geometry dialog box

ADD PART…: This function allows the user to select one or more parts from part list as tool. The selected parts are displayed in Parts List window. Refer to Chapter 4 for description about selecting parts.

 

REMOVE PART: This function allows the user to remove selected parts form the Part List.

 

ADD ELEM…: This function allows the user to add selected element(s) to selected part.

 

COPY ELEM…: This function allows the user to COPY or OFFSET element(s) from existing elements. If only one die face is defined, the user may COPY or OFFSET tools (punch and binder) using this function. The COPY ELEMENTS dialog box illustrated in Figure 8.2.61 is displayed.

 

Figure 8.2.61 Copy Elements dialog box

OFFSET ELEMENTS: This function allows the user to offset new elements from existing elements and include these elements into the new part in current tool. The default name of new part is OFFSET01, OFFSET02, etc.. Usually, this option is toggled off, indicating only copy element operation is chosen.

 

THICKNESS: Element offset thickness. Default thickness is 1.0 (mm). The user may key in desired offset distance. The user may reverse offset direction by setting a negative offset thickness, such as -1.0.

 

SELECT…: This function allows the user to select element(s) for copy or offset operation. If the button is hit, the SELECT ELEMENTS dialog box is displayed.

 

CLEAR: This function allows the user to clear selected elements. The user may use SELECT button to re-select elements.

 

APPLY: After selecting elements, the user may click APPLY to perform copy or offset operation.

 

UNDO: The user may click UNDO to cancel the last operation.

 

EXIT: Exit COPY ELEMENT dialog box.

 

CREATE GUIDE/PIN: This function allows the user to create GUIDE and/or PIN. A new part for the GUIDE is created and included as current tool. Default name of new GUIDE is ACC0000, ACC0001, etc.. For detailed description of GUIDE and PIN, refer to Section 9.6.

 

DISPLAY: This function allows the user to display parts that are corresponding to the current tool on the display screen. After tool geometry is defined, parts corresponding to this tool are displayed in the part list.

 

REFERENCE: In multiple stages setup, one stage can refer to the tools of other stages. However, the tools in the identical stage cannot be referred to. This function is commonly used to define the tools for gravity load stage. The reference tool and the referenced tool share the same property. The Reference tool dialog box is illustrated in Figure 8.2.62.

Figure 8.2.62  Reference tool dialog box

 

POSITIONING

 

This function enables the user to position tool by entering the travel distance between tool and HOME, as shown in Figure 8.2.63. Show geometry button is used to show/hide the display of the current tool.

 

Figure 8.2.63  Tool Positioning

 

WORKING DIRECTION

 

In each setup, a unique working direction of tool has to be defined. Working direction is the direction of tool traveling towards the blank. Note: Working direction is a vector originated from the tool and pointing towards the blank. It is not the actual direction of tool travel. The vector can be pointing to the opposite direction of direction of tool travel.  The interface of working direction is illustrated in Figure 8.2.64.

Figure 8.2.64 Define Working Direction

DIRECTION: This function displays the working direction of current tool as a vector. Default starting point of the vector is WCS (0, 0, 0). The coordinate of the end point is also displayed in this box. The User may click  button to modify the working direction using the DEFINE DIRECTION dialog box illustrated in Figure 8.2.65.

 

Figure 8.2.65 Define Tool Working Direction of Tool

        DIRECTION

        This function allows the user to determine direction using defined vector. The origin of the vector is similar to the origin of current coordinate system. The coordinate of end point is determined by the user.

 

          Define X coordinate for the endpoint of vector.

          Define Y coordinate for the endpoint of vector.

          Define Z coordinate for the endpoint of vector.

 

        REVERSE

        This function allows the user to reverse the defined direction.

 

        2-POINTS/NODES

        This function allows the user to select two points or nodes to define a direction.

 

        3-POINTS/NODES

        This function allows the user to select three points or nodes to define a direction. The defined direction is perpendicular to the plane defined by the three selected points/nodes. The direction follows the right hand rule.

 

        ELEMENT NORMAL

        This function allows the user to select an element. The normal direction of selected element is defined as the desired direction.

 

        EXISTED LCS

        This function allows the user to select a coordinate axis from the defined LCS as the desired direction. If no LCS is defined in the database, this button is disabled. After hitting this button, the dialog box illustrated in Figure 8.2.66 is displayed. The user proceeds to select a LCS and direction for CS.

 

 

Figure 8.2.66  Existed LCS dialog box

 

MOVE: This function is used to displays the tool travel distance along the working direction from tool’s original position after positioning operation. If negative value is observed, the tool moves in the opposite direction of working direction. The user can directly enter the travel distance to adjust tool.

 

CONTACT

This function allows the user to define contact parameter between the blank and tools.

 

OFFSET: When defined tools are copied from the die face, contact offset is required for corresponding tools. For example, if the new punch is generated according to die face, an offset value is required for the corresponding punch. The blank thickness is used as the offset value. The user may change the value according to requirement.

 

FRICTION COEF: Allow the user to specify coefficient of friction.

 

ADVANCED: Define advanced parameters for contact interface. Detailed description of contact definition is available in Section 8.2.4.4 and LS-DYNA User’s Manual.

POSITIONING

This function is used to control the initial position of tooling and blank in the stamping simulation, relatively to the original position. This function includes both auto and manual positioning illustrated in Figure 8.2.67. The user may select the checkbox of OnBlank option to activate auto positioning. Alternatively, the user may key in travel distance of the tool in the input box for Tools to perform manual positioning. After entering the travel distance of blank and/or tools, the user clicks ENTER key to update the position of blank and tools in display screen.

 

Figure 8.2.67 Tool Positioning

BLANK POSITION: The user may key in any value in the input data field to position the blank. The user may also select a tool from the drop-down list as reference for positioning of blank, and show the travel distance of the blank relatively to its original position. If the latter option is chosen, the checkbox of OnBlank option for the selected tool is disabled.

 

TOOL MOVEMENT: All the defined tools are listed in the Tools field. The user may define the initial position of tooling by entering a value for each tool in the input data field. If the checkbox of OnBlank option for the selected tool is toggled on, the tool position is automatically calculated according to the blank position. The movement of tool relatively to its original position is listed in input data field. Modification of this value is prohibited.

 

NOTE: Auto positioning of tools and blank are carried out along the working direction. The user must specify working direction for each tool prior to performing auto-positioning.

 

ROUND: Press this button to round the auto-positioning values.

 

RESET: Clear all the travel distances between tools and blanks and reset to the initial position prior to positioning operation.

 

OK: Save result of positioning and exit the POSITIONING dialog box.

 

CANCEL: Exit the POSITIONING dialog box without saving positioning result.

 

AUTO ASSIGN

This function is used to assign the parts with standard names as the corresponding tools, such as BLANK, BINDER AND PUNCH. It is recommended not to use this function in multi stage analysis.

 

8.2.4.5       PROCESS

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 and delete any process. The basic process setup interface is shown in Figure 8.2.68.

Figure 8.2.68 Process definition page

PROCESS LIST

On the left of 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 to list to switch the current process. Default process is specified according to defined process type. For example, if SINGLE ACTION process is chosen, closing and drawing are created as 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 PROCESS

 

This function allows the user to add a new process in current setup. The user may click ADD button to display the new process interface illustrated in Figure 8.2.69.

Figure 8.2.69  New process interface

STEP NAME

Allow the user to name the current process. Default process names are step1, step2, step3, etc.. The user may define a unique name for each process for the ease of identifying the process.

 

 

DEFAULT SETTING

Allow the user to select default setting for the new process. In default setting, the user may select the program default parameters for the new process. Otherwise, the user may choose to use the parameters of any defined process.

 

USE SETTING OF STEP: New process adopts parameters of existing process. The user may select an existing process from pull-down list.

 

USE DEFAULT SETTING: Use system default parameters to define a new process.

 

 

DELETE PROCESS

 

This function allows the user to remove current process from setup. The user may select a process from the process list as current process, following by clicking DELETE button to display the dialog box illustrated in Figure 8.2.70. Click on OK button to delete the current process or Cancel button to abort the delete operation.

Figure 8.2.70 Delete process dialog box

 

 MOVE STEP

This function allows the user to organize sequence of processes.

 

PROCESS NAME & TYPE

 

NAME

Display name of current process. The user may type in a new name in the input data field of Name.

 

TYPE

Allow the user to select type of current process: Drawing or Hydroforming.

 

TOOL CONTROL

This function is used to control action of tools define travel speed, blank holding force, travel curve, etc. in current process. A typical tool control option is illustrated in Figure 8.2.71.

Figure 8.2.71 Tool Control Option

 

TOOLS

List all active tools of current process. By default, the non-active tools in the current process are not listed. The user may toggle on checkbox of SHOW ALL option to display all tools.

 

SHOW ALL

Display all defined tools in tool list.

 

ACTION & VALUE

This group lists all tool control options. Each tool can be controlled by one of the following option: NON-ACTIVE, STATIONARY, VELOCITY, DISPLACEMENT and FORCE.

 

NON-ACTIVE

Defined tool is not used in this stage.

 

STATIONARY

Defined tool is stationary in this stage.

 

VELOCITY

Motion of defined tool is controlled by velocity curve in this stage. The user may select one of the standard velocity curve option provided in Auto Setup: TRAPEZOIDAL, SINUSOIDAL, SIN.W-H, TRIANGULAR and VARIABLE. The standard velocity curves are illustrated in Figure 8.2.72. The user may type in peak velocity in the data input field of selected tool. Default velocity of die for drawing process is set as 5000 mm/s. For closing process, the default velocity of binder is set as 2000 mm/s.

 

 

a)   TRAPEZOIDAL                             b) SINUSOIDAL

 

c)  SIN.W-H                            d) TRIANGULAR

Figure 8.2.72 Types of standard velocity curves

If user-defined curve is chosen, the  button is activated to enable the user to define travel curve using the EDIT LOAD CURVE dialog box.

 

DISPLACEMENT

Tool travel of this stage is controlled by displacement-time curve. The user clicks DEFINE 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 two types of force control: CONSTANT and VARIABLE. If constant force option is chosen, a constant force value is required. For variable force option, the user clicks DEFINE button to create force- time curve.

 

 This button is activated when force control is selected. The user may use this button to define RIGID BODY STOPPER. Rigid body stopper is applied on the binder ring to control upper and lower displacement of binder ring. The user may specify the parameters for rigid body stopper illustrated in Figure 8.2.73.

 

Figure 8.2.73 RIGID BODY STOPPERS dialog box

 

UPPER DISP.: The limit of upper maximum displacement of the tool.

 

LOWER DISP.: The limit of lower maximum displacement of the tool.

 

MAX. VELOCITY: Control the maximum velocity of rigid body stopper during the process.

 

BEGIN TIME: Activate RIGID BODY STOPPER.

 

END TIME: De-activate RIGID BODY STOPPER.

 

DURATION: Duration of RIGID BODY STOPPER.

 

After setting up the RIGID BODY STOPPER, the label of  button becomes blue. Detailed description of RIGID BODY STOPPER is available in LS-DYNA User’s Manual.

  

   PRESSURE

   Apply pressure on selected tool in the current stage. The defined pressure curve is converted into force curve during output of input decks.

 

ASSOCIATION

Allow the user to define contact between two tools.

 

 

USER DEFINE CURVE

In each setup, all the defined curves are managed by the curve editor. The user may create, import, modify existing curve using the function provided in the EDIT LOAD CURVE dialog box illustrated in Figure 8.2.74.

Figure 8.2.74  EDIT LOAD CURVE dialog box

IMPORT CURVE

Allow the user to import file consisting curve data. The extension of curve files is “.cur”. The curve file is defined according to the standard LS-DYNA keyword format.

.A typical curve format is shown in Figure 8.2.75.

Figure 8.2.75  Typical curve format

EXPORT CURVE

Allow the user to export current curve to a text file with “.cur” extension. Click the Export button to display EXPORT CURVE dialog box, following by typing in the name of file. Then, click Save button to store the file in selected folder.

INPUT

This page displays data the points of current curve. If no curve is defined, user may create a new curve by entering point coordinates. The user may modify data points of existing curve using function such as add, delete, insert and clear.

 

ADD: Allow the user to add a data point at the end of curve. Click 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, following by hitting Apply button to complete the operation.

INSERT: Allow the user to insert a data point after current data point. Prior to clicking this button, the user may use mouse cursor to choose the current data point. The selected data point is highlighted in yellow. Next, click INSERT button to create two empty input data fields, following by typing in the data point and hit Apply button to complete the operation.

DELETE: Allow the user to remove current data point.

CLEAR ALL: Allow the user to clear all data points in current curve.

APPLY: The user may click APPLY button after performing add, insert or delete 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 linearity, quadratic, cubic, and sin (cos). When defining FLC curve, the Keeler’s empirical equation is used.

 

Figure 8.2.76 Formula Page

 

TYPE: Allow the user to select type of formula used to create a curve. Type of formula includes SIMPLE, QUADRATIC, CUBIC, SIN and COS.

INTERVAL: Allow the user to specify interval of abscissa. Default value varies according to type of selected formula.

ABSCI-START: Allow the user to specify start point of abscissa. Default value varies according to type of selected formula.

ABSCI-END: Allow the user to specify end point of abscissa. Default value varies according to type of selected formula.

PARAMETER: Allow 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. By default, these parameters are set to 1.

APPLY: After defining parameters, the user may click APPLY button to create curve. The created curves are displayed in curve display window, 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 SCALE, TRANSLATE, etc.

 

Figure 8.2.77 Curve Operation

 

MODE: Define the curve operation mode. Including SCALE and TRANSLATE.

PARAMETER: The user may input curve operation parameters in 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.

APPLY: After specifying operation parameters, the user may click APPLY button to complete the operation and refreshed the curve displayed in the curve display window.

 

CLIPBOARD

This function allows the user to temporarily save the current curve to the clipboard of Auto Setup. The user may load the curve saved in the clipboard into the current curve interface. The user may also compare the curve in clipboard and current curve. The clipboard interface is illustrated Figure 8.2.78.

Figure 8.2.78 Clipboard Interface

DELETE: Remove selected curves from clipboard.

CLEAR All: Remove all data stored in clipboard.

RESTORE: Allow 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 clipboard to overwrite the current curve. The program displays a dialog box illustrated in Figure 8.2.79 to prompt the user for confirmation.

 

Figure 8.2.79 User Prompt dialog box

BACK UP: Copy 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.: Number of curves in clipboard.

TYPE: Type of curve such as time curve.

PNTS: Number of points on the curve.

STATUS: The user may control whether the curve in clipboard is displayed in show curve window. If the option is selected, the curve is displayed in gray in the curve display window (current curve in displayed in blue).

Note: The curve data on clipboard is not saved in database file. After the user exited eta/DYNAFORM, all curves in clipboard are automatically removed.

 

TOOL BAR IN SHOW CURVE INTERFACE

The tool bar is displayed at the top of curve display window. The user may operate the curves by using the functions provided in the tool bar. Tool bar interface is illustrated in Figure 8.2.80.

 

Figure 8.2.80 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 mouse cursor to desired location on the curve and click 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 display window. The point that is the closest to the cursor is highlighted with a small circle. The user clicks 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 8.2.81.

 

Figure 8.2.81 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  Allow 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 option allows user to pan the curve in the show curve window.

ZOOM BY WINDOW  This function allows the user to zoom in the curve by window. 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 the curve.

ZOOM BY DRAG  This function allows the user to zoom the curve view by dragging the mouse. The user clicks left mouse button of 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 allows the user to fit the entire curve in the curve display window.

 

DURATION

This function is used to control the duration of current stage. The duration interface is illustrated in Figure 8.2.82. 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 requirement for different forming stage. The user may select an appropriate control method according to the requirement of the current setup.

 

Figure 8.2.82 Define duration time

DURATION TYPE

The user may select a control type from the TYPE pull-down menu.

TIME: Allow 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 Allow the user to specify tool travel distance along the working direction. The user needs to select a reference tool from tool list illustrated in Figure 8.2.83. Then, define the displacement of the tool along its working direction. The time of travel is automatically computed by Auto Setup.

Figure 8.2.83  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 Auto Setup, working direction should be assigned for all tools.

 

CLOSURE Allow the user to choose closure time required to close two tools as duration time. The user needs to select two reference tools from tool list illustrated in Figure 8.2.84.

 

Figure 8.2.84  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: Allow 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 8.2.85.

 

Figure 8.2.85 Until home

 

OUTPUT D3PLOT FILE CONTROL

 

This function allows the user to define the number of output files in D3PLOT format. By default, the D3PLOT files are output in equal time interval. The user may also insert the required special frames.

 

Note: The special frames can only be inserted when the motion velocity or displacement of tools are defined in this stage.

 

MAX. FRAMES

Define number of D3PLOT result files for the current stage simulation. The user may change this value in the input data field. If special frame is not defined, D3PLOT files will be generated with equal time interval.

 

EDIT

The user may insert some special frames in D3PLOT output dialog box. Click this button to display the D3plot output dialog box illustrated in Figure 8.2.86.

 

Figure 8.2.86  Add Special Output Frame

Max. number of frames: Display the total number of output frames in the D3PLOT files for the current stage. The user can also perform modification here.

 

ADD: The user may click this button to add special frames. After clicking this button, the user may enter Interval for output and Distance from bottom. The bottom indicates the end position for tool motion in this stage.

 

DELETE: The user may click this button to delete the added special frames.

 

APPLY: The user may click this button to add special frames to the list.

 

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.

 

After the user added 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 8.2.87.

 

Figure 8.2.87 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 Hydro Option illustrated in Figure 8.2.88.

 

Figure 8.2.88  Hydro Forming

 

HYDRO MECH. PARAMETERS

In Hydro mech. field illustrated in Figure 8.2.89, the user may specify internal fluid pressure vs. time curve, boundary and direction of applied internal fluid pressure.

 

Figure 8.2.89 Hydro Mech. parameters setup

 

 

ABOVE: In press coordinate system, fluid pressure is applied on the top of blank illustrated in Figure 8.2.90.

Figure 8.2.90  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 8.2.91.

Figure 8.2.91  Fluid pressure is applied on bottom of blank

BY NORMAL: Direction of fluid pressure is defined according to normal vector of blank element. The user needs to check and ensure the element normals are consistent. Otherwise, the setup is incorrect.

 

PRESSURE: Set up internal fluid pressure vs. time curve. This parameter is essential in sheet hydro forming. The user may click  button to key in values of internal fluid pressure vs. time curve in the define dialog box illustrated in Figure 8.2.92.

Figure 8.2.92 Hydro Pressure-Time Curve Defines

CONSTANT: Define fixed internal fluid pressure. The user may key in a constant fluid pressure in 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 EDIT button to display curve define interface. For detailed description of curve definition, refer to Chapter 12.

 

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 8.2.93.

Figure 8.2.93  Define fluid pressure boundary

INSIDE Apply fluid pressure inside of the defined boundary line.

 

OUTSIDE Apply fluid pressure outside of the defined boundary line.

 

PROJECT 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 click this button, the direction define dialog box is displayed. Detailed description of this function is provided in Section 8.2.3.2. 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 WCS.

 

POINTS: Display the number of points along curve.

 

INPUT LNS…: The user may define region subjected to applied fluid pressure by defining a closed loop curve. After clicking this button, the SELECT CURVE dialog box is displayed.

 

INPUT PTS…: If no curve is provided in the database, the user may define a closed loop curve by clicking this button to create line using points.

 

Notice: 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 8.2.94.

 

Figure 8.2.94 Confirmation dialog box

 

OK: Accept the current setup and exits the dialog box.

 

CANCEL: Abort 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 only part of elements on the blank is subjected to applied fluid pressure.

 

 

8.2.4.6       CONTROL

In Control parameter page, the user is allowed to set up basic parameters to control calculation. These parameters include time step size, Selective mass scaling, Refining meshes, Output ascii file, etc. Control parameter setup interface is illustrated in Figure 8.2.95.

 

GENERAL

 

SELECTIVE MASS SCALING: Allow the user to determine whether to use the selective mass scaling or not. If this option is selected, the time step will be reset to -1.2e-005. Therefore, the user should toggle on this option first, and then modify the time step.

 

TIME STEP SIZE: Allow the user to set up time step size. Default time step size is -1.2e-6.

 

ADVANCED…: Advanced setup for basic parameters. The interface is illustrated in Figure 8.2.96.

Figure 8.2.95  Basic control parameter setup interface

Figure 8.2.96  Basic parameter advanced setup interface

 

 

ADAPTIVE MESHING

 

TIMES (ENDTIME/ADPFREQ): Allow the user to set the adaptive frequency (ADPFREQ). Default value is 40.

 

TOLERANCE IN DEGREE (ADPTOL): Set angle change between elements during adaptive meshing. If angle change is greater than 5°, the coarse elements are divided into fine elements.

 

MAX. REFINEMENT LEVELS (MAXLVL): Set maximum allowable refinement level. Default level is 3, which mean a square/triangular element is split twice. For example, 1 square element is split into 16 square elements using MAXLVL of 3.

 

ADVANCED…: Advanced setting for adaptive meshing. The interface is illustrated in Figure 8.2.97.

Figure 8.2.97 Adaptive advanced parameters

OUTPUT ASCII FILE

The first column is used to control the output of database result files and the second column is used to control the output time interval. If interval is not selected, the program will use the default time interval. If the interval option is selected, the user may input the time interval in the textbox. An example is illustrated in Figure 8.2.98.

 

Figure 8.2.98  Output ascii file setup interface