printing _getting started with hypermesh - hm-1000

Getting Started With HyperMesh - HM-1000

HyperMesh is a high performance finite element pre- and post-processor that allows you to build finite element and finite difference models, view their results, and perform data analysis.

This tutorial introduces HyperMesh, as well as many basic concepts and tasks that are needed to get started with HyperMesh, and which serve as pre-requisites for most other HyperMesh tutorials. It covers:

• Launching HyperMesh

• The user interface

• Using the on-line help

• File input and output

• Viewing the model using options from the permanent menu

• Using the mouse for model viewing, rapid menus and entity selection

• Controling the display and visual attributes

• Menus and menu items

• Database relationships: elements/components/materials/properties

• Setting current collectors, element size and element order

• Interfacing with solvers

• Creating collectors

• Reviewing and editing card images

• Organizing and deleting entities

Each section of this tutorial takes between 5 and 15 minutes to complete. Individual sections can be taken independently although it is recommended to take all of them and preferably in the order presented.

A couple of sections build on previous sections. The only pre-requisite for most sections is to have the bumper model used in this tutorial loaded in HyperMesh (See File input and output for instructions on how to load the model).

The file referenced in this tutorial is located in the <install_directory>/tutorials/hm/ directory. If you do not know the location of the HyperWorks installation directory, see Finding the Installation Directory <install_directory>, or contact your systems administrator.

Launching HyperMesh

This section discusses how to launch HyperMesh and the location of the working directory.

1. Launch HyperMesh.

If you do not know how to start HyperMesh, and you are:

On UNIX

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The most common method is to add the <install_directory>/scripts/ directory for the HyperWorks installation to the search path for a user, then start HyperMesh by simply typing "hm" at the command line. Some system administrators, however, incorporate site-specific scripts to carry out some additional tasks or enable configuration specific options. Please ask your systems administrator if this is the case at your location and for the procedure to start HyperMesh.

On Windows

HyperMesh can be started by using the Windows Start menu, and selecting Programs/ HyperWorks <version number>/Altair HyperMesh. It can also be started from a command line by pointing to hmopengl.exe in the <install_directory>/hm/bin/ directory. A more convenient method is to create a shortcut to hmopengl.exe, and use that shortcut to start the software.

You should get the HyperMesh interface:

The HyperMesh interface

2. Identify your HyperMesh working directory.

HyperMesh runs in a working directory. This directory is used as the starting point for the file browser, and the default directory to which message and session command files are written.

For UNIX systems, the working directory is the directory from which the HyperMesh starting script command was issued.

On Windows, the working directory is the Windows standard working directory and depends on the version of Windows you are running. For example, on Windows XP, it is %userprofile%\My



Documents. The working directory can be set to any directory when a shortcut to the HyperMesh executable is used. It is set on the shortcut’s shortcut tab in the Start in: field.

The User Interface

The HyperMesh Interface contains several areas (see figure above). Each is described below.

Title bar The bar across the top of the interface is the Title bar. It contains the version of HyperMesh that you are running and the name of the file you are working on.

Graphics area The Graphics area under the Title Bar is the display area for your model. You can interact with the model in three-dimensional space, in real time. In addition to viewing the model, entities can be selected interactively from the Graphics area.

Macro menu This area contains five pages of macros that perform various functions. The Disp macro page is active and is shaded to signify this. The Disp page macros control how a model displays in the Graphics area.

The other macro pages available are QA (contains element checking macros), Mesh (contains macros associated with creating and editing meshes), User (contains macros you create), and Geom (contains macros related to working with a model’s geometry).

The contents of the macro menu changes based upon the selected User Profile (see Interfacing with solvers).

Header bar The Header bar separates the Graphics area from the Panel area. The left end of the Header bar displays your current location. At this time, you will see Geometry displayed. The three fields on the right side of the header bar display the active user profile, current component collector and current load collector. The latter two fields are blank.

As you work in HyperMesh, any warning or error messages also display in the Header bar. Warning messages appear in green and error messages appear in red.

The quit button on the rightmost end of the Header bar ends the HyperMesh session. When you select quit, if changes have not been saved a save file information confirmation message appears so you can save your changes before HyperMesh closes down.

HintYou can hold the left mouse button down on top of a panel to see a description for it in the Header bar.

Permanent menu The Permanent menu is always displayed. The upper portion contains model and view manipulation tools. The lower portion provides access to the following panels.

options takes you to the options panel allowing you to modify many of the default settings in the HyperMesh work environment. (keyboard hotkey o).

card takes you to the card panel where you can review and



edit the card images defined in the template file associated with the model.

global takes you to the global panel where you can control global model parameters accessed by several different panels. These parameters remain constant until changed. Use this panel to specify which template file you want to use. The panel controls which collectors (a collection of data pertainent to a given entity and handled as a group) are active. Any entities you create are stored in the active collectors. (keyboard hotkey g)

help allows you to access the on-line help. On panels, you obtain context sensitive help describing the functions of the panel with links to various terms described on the panel. (keyboard hotkey: h)

disp allows you to access the display panel where you can select which collectors are displayed on the screen. (keyboard hotkey: d)

allows you to view the HyperMesh model structure by organizing assemblies, components, multibodies, properties, materials, and beamsectcols into a tree-like display.

vis is available when you use the performance graphics engine. It allows you to assign a set of display attributes to each component of your model.

Page menu The Page menu allows you to select different sets of functions.

The Geom page contains functions having to do with the creation and editing of geometry.

The 1D, 2D, and 3D pages contain element creation and editing tools grouped according to element type.

The BCs page (boundary conditions) contains functions to set up the analysis problem and define the boundary conditions.

The Tool page contains miscellaneous tools and model checking functions.

The Post page contains post-processing functions.

Panel menu The Panel menu displays for each page the functions available on that page. You access those functions by clicking on the button corresponding to the function you wish to use.

Note Some functions are located on several pages. For example most of the functions in the leftmost column (files, collectors, etc) can be accessed from each of the seven pages.

Using the on-line help

In this section access the on-line help for the geom cleanup panel and get familiar with the HyperMesh help system.



1. From the main menu, select the Geom page.

2. Go to the geom cleanup panel.

This panel provides tools to modify your geometry data and prepare it for meshing operations.

3. From the permanent menu, click help.

A help window describing the basics of the geom cleanup panel displays. This help page contains a description of the panel as well as links to the help pages for its various sub-panels, and How Do I’s to assist you in using the panel’s functions.

4. Review the content of the help.

The HyperMesh online help system is context sensitive. Whenever you press the help button while you are in panel, you will be taken directly to the help page for that panel.

5. Click the edges link.

This takes you to a new help topic describing the edges sub-panel of the geom cleanup panel.

6. To return to the previous help topic, click the Back button located at the top of the page.

This takes you back to the page you started from. Notice how the Back button is therefore grayed out.

Navigation through the on-line can be done following links and using the Back button as was just done here. You can also navigate through pre-defined browse string using the double-arrow browse

buttons, . Browse strings are goupings of topics that have a relationship between them, whether they complete one another in covering a specific subject, or are simply part of a broader concept.

The browse buttons are only active for topics that belong to a browse string. For example, the current topic (geom cleanup panel help) does not belong to any browse string as these arrows are currently disabled.

7. Go down the geom cleanup help page until you reach the Note.

This note provides provisions regarding the actual appearance of this panel, depending on the user profile currently loaded in HyperMesh.

8. Click the link User Profiles.

A new help topic appears. Notice how the double-arrows are now active to go forward.

9. Browse forward in the browse string using the forward double arrows.

Once you are passed the first topic of the string, the back double-arrows are active and allow you to go back to the previous page of the browse string.

While the Back button takes you to the previously displayed page, the browse buttons allow for navigation within a set sequence of topics only. In this particular example, the browse button would only allow you to browse through pages that belong to the User Profiles browse string and would not take you back to the geom cleanup panel help, which does not belong to any browse string. Using the Back button would take you back to this topic after taking you through all the topics you have visited since you started there.

Once the help is launched, the entire help system is also available using the help contents, index and find tabs.

10. Click the index tab and type geom cleanup at the prompt on the Index tab of the Help Topics dialog that popped up.



The help system returns matches for the text you typed.

11. Select geom cleanup panel from the list and click Display.

This takes you again to the geom cleanup panel help, although you are not back at the starting point of the history of pages as signified by the Back button being available. Using the Index, you simply made a jump to a new page.

12. Click Contents at the top of the window to bring up the Help Topics dialog and the Contents tab.

This tab allows you to review the table of content of the help system for the HyperWorks applications installed at your site. This is a tree-like representation of the content of the help with books representing groupings of books and/or topics (represented with a question mark).

13. Expand the Altair HyperWorks book by double clicking it, or selecting it and clicking Open.

14. Open the HyperMesh book, and expand some of the available books to review their content.

15. Bring up any topic by double clicking it in the tree structure.

When you need to find specific information, you can look for it in the table of content using the Contents tab, or have the help system look for it by using the Find engine.

16. Click Find to bring up the Help Topics dialog with the Find tab.

17. Click Options… to review the search engine options, and click OK to close the Find Options dialog.

18. Experiment with the Find tab by typing some words and looking at the results.

The result is a list of topics matching words you entered and the criteria you set in the Options. You can then review a topic of interest from the list by double clicking it, or selecting it and clicking Display. To review another result topic, simply click Find again as the same list of topics for the criteria specified will still be available.

19. Close the help.

Notes If the help button is clicked from a main menu page, the help system will start at the topmost book level of HyperWorks help, and you can navigate your way through the help system using the Help Topics dialog.

The help system can be started outside of HyperMesh from the Start menu in Windos (Start/Products/HyperWorks <version>/Altair HyperWorks Help) , or by typing winhlp at the UNIX command line from within the <install_directory>/scripts directory.

File input and output

In this section, you use the files panel to retrieve a HyperMesh database. The files panel is primarily used for all the input and output of files, and setting up solver templates.

1. From any page, select the files panel (leftmost column).

2. Select the hm file sub-panel by clicking the corresponding radio button.

This sub-panel is used to save and retrieve HyperMesh binary files, which contain all of the information in the HyperMesh database, including geometry and finite element model data. While HyperMesh has no specific file extension requirements, the typical extension is .hm. Only one HyperMesh binary database can be opened with this sub-panel per session.



The four green buttons on the right side of the panel are used to save or retrieve the HyperMesh database. The save as… and retrieve… launch a windows style file browser to allow you to locate the desired file on your system. The save and retrieve buttons (without the …) simply read or write to the filename listed in the file: field.

3. Click retrieve….

An Open File… dialog appears. The starting point is your current working directory, and the filter for Files of types… is set to HyperMesh binary files (*.hm*).

Open files dialog

4. Change directories to the <install_directory>/tutorials/hm directory.

If you do not know the location of the <install_directory> installation directory, see Finding the Installation Directory <install_directory>, or contact your systems administrator.

5. Select the file bumper.hm and click Open.

You can also double-click the file name to close the file dialog and read the file into Hypermesh.

The bumper model displays in the graphics area. Notice the file: field contains the path and file name just loaded into HyperMesh. The path and file name also display in the title bar at the top of the HyperMesh window.

If at any time you would like to revert to the original model (discarding any changes you may have made), click the retrieve button (the file browser will not open). To save any changes you have made, (overwriting the original file) click the save button. If you would like to save your changes with a different file name or location, use the save as… button to open the file browser, or update the path and name in the file: field and click save.

6. Look at the other sub-panels in the files panel by clicking their corresponding radio buttons:

import HyperMesh can import HyperMesh binary files (HM MODEL), geometry files (GEOM), finite element information (FE), weld location and connection data (WELD). Simply select first the type of data to import, and then the appropriate import translator.

When data is imported into HyperMesh, it is appended to the current session database. An import translator reads data imported and converts the native file format into one HyperMesh understands. Import translators are included for many finite element solver input formats, as well as many common geometry formats.



export The export functionality is used to convert information in a HyperMesh database into a solver formatted input deck, to export geometry as IGES data, or to export weld information. In order to write data as a solver input deck, HyperMesh uses feoutput templates to define the output format. The feoutput templates also define the card images of the different entities. (See Interfacing with solvers)

Tip: Load the feoutput template prior to creating any finite element entities, like materials, elements or loads. In this way, the solver specific entity type and required properties can be defined most efficiently as the model is created.

command The command subpanel allows you to execute a HyperMesh command file (a file containing commands allowing you to automate or re-create HyperMesh sessions).

template The template sub-panel allows you to specify which solver template file you want to load.

results From results, you can load HyperMesh results file obtained by translating (solver panel or command prompt) solver result files.

Viewing the model using options from the permanent menu

The top half of the permanent menu contains view manipulation tools. The functions can be activated either by clicking the button on the permanent menu, or by pressing the corresponding key on the keyboard (for functions with a single letter on the button), or the four arrow keys.

Permanent menu

Zoom functions The zoom functions allow you to scale the size of the model display in the graphics area.

Try each of the five zoom functions on the bumper.hm model loaded in the previous section.

z Circle zoom function. When activated, move the mouse into the graphics area, then click and hold the left mouse button. Circle the part of the model you want to zoom in to, and upon releasing the mouse button, the view will be adjusted.

f Fit function. Fits the entire model to the graphics area.

+, - Incremental zoom functions. Zoom the view in or out by a zoom factor specified in the options panel, modeling sub-panel.

s Slide zoom function. Click and hold the mouse in the graphics



sarea, then move it vertically to smoothly zoom in or out.

Rotation functions Try the rotation functions.

←↑→↓ The four arrow buttons will incrementally rotate the model in the direction of the arrow. The rotation increment is set to 15 degrees by default, and can be changed in the options panel, modeling sub-panel.

a Arc rotate. Rotate the model as if grabbing and dragging it with the mouse.

r Dynamic rotate. Rotate the model in the direction of the vector created from the rotation center to the mouse position. Rotation speed is proportional to the distance from the rotation center to the mouse.

Other functions Try some of these functions.

p Plots the model to refresh the screen. Often, after deleting elements or lines, the entities adjacent to those deleted are not drawn correctly. Clicking the p button re-draws the model.

c Center the model. Use this function to reposition the model by selecting a new screen center. The point selected is centered on the screen and the model repositioned accordingly.

b Back to the previous view. Allows you to toggle between two views.

View View pop-up menu. Set basic views, such as front, back, right, left, top, bottom, and access five view memories that can be used to save and restore specific view settings for the model. To save a specific view, type in a name and click the corresponding save button. To close the menu, move your mouse off it. (keyboard hotkey: v).

Spherical Clipping. Displays the specific area of a model that is inside a three dimensional sphere, masking everything outside the sphere.

Surface Transparancy. Sets the transparency level for the surfaces of selected components. The effects are only seen in shaded mode and with models containing surfaces.

Using the mouse for model viewing, rapid menus and entity selection

The mouse attached to your system is integral to HyperMesh. While the left mouse button is used for entity selection, the right mouse button is used for de-selecting entities. Holding either left or right mouse buttons down will allow you to pre-highlight the entities to select or de-select.

Rapid menu allows you to use the middle mouse button to quickly perform common operations without frequently moving the mouse between the graphics region and the panel region. The function button that is assigned to rapid menu is outlined in black in the panel.

With the bumper.hm model loaded (see File Input and Output):

1. From the Tool page, go to the mask panel.



2. Go to the mask sub-panel.

Notice how the return button is outlined in black.

3. Press the middle mouse button.

HyperMesh automatically takes you back to the Tool page.

4. Enter the mask panel, mask sub-panel again.

5. With the entity selector set to elems, go to the graphics area and left mouse click the dot located at the centroid of several elements.

The elements highlight and are put into a mark. Note how the mask button is now outlined in black. This is the function that would be performed should you press the middle mouse button.

6. Right mouse click the centroid of some of the elements you previously selected.

These elements return to their original color and are removed from the mark.

7. Hold your left mouse button down and move over the centroid of various elements.

Note how elements temporarily highlight as you move over them.

8. Relese the left mouse button over one element and note how the elements is selected.

9. Click mask or press the middle mouse button to mask these elements.

Note how after performing this function, the return button is again outlined in black.

10. Click unmask all to bring all the elements back.

Some operations require pressing a keyboard key in addition to using the mouse. In addition to the view controls on the permanent menu or their keyboard equivalents, the three mouse buttons, used in conjunction with the control key (CTRL) on the keyboard, allow you to quickly and conveniently access common view controls.

11. Try the following:

CTRL + Left mouse button activates the arc rotate function. Hold down the Ctrl key, then click and hold the left mouse button in the graphics area. While holding both the Ctrl key and the left mouse button, you can drag the mouse to rotate the model in the direction of the mouse movement. One quick click will let you re-define the center of rotation which can be set to a node location for example.

CTRL + Middle mouse button

activates the circle zoom and fit functions. While holding down the CTRLkey, click and hold the middle mouse button, then draw a zoom circle around a part of your model. When you release the middle mouse button, the view will be adjusted to fit the circled area to the graphics screen. If you hold down the CTRL button and quickly click the middle mouse button, the model will fit to the screen.

Note This function also applies to mice equipped with scroll wheels. Press down on the wheel as if it were a mouse button.

CTRL + Right mouse button activates a drag pan mode. When holding down the Ctrl key, you can click and grab the model with the right mouse



button, then translate it in the plane of the screen by dragging it with the mouse.

When collecting entities in a panel where the selection by window is available (see Menus and menu items), use the SHIFT key to access the quick window selection mode. Hold down the shift key to access it and do a left mouse drag or right mouse drag.

In any panel that can select entities by window (lines, nodes, elems, comps etc. not nodelist or linelist or single node collector), shift-left drag will draw a rubber band window and selects the entities in that window. Now you can use middle mouse (rapid menu) to perform the function of the panel.

12. Hold the SHIFT key down, and in the graphics window, do a left mouse click to bring up the four options for the quick window selection.

Quick window options

13. Select the top left option for which a rectangular window can be selected and the elements for which the centroid falls inside the window will be selected.

14. Place the mouse anywhere in the graphics window, do a left mouse click and hold the left mouse button down.

15. Drag the mouse to build a window, and release the left mouse button.

The elements are highlighted. You could now mask these elements.

16. Click return to go back to the main menu.

Note In the display panel the quick window with left mouse will turn off the collectors in the window and the right mouse quick window will turn on the collectors that would have been in the window if displayed.

Controling the display and visual attributes

This section looks at the display (disp) and visual (vis) panels from the permanent menu and shows you how you can control the display of what you see (elements and geometry) and how you see it.


1. Click disp on the permanent menu to enter the display panel.

Display panel

The collector type selector is set to comps. On the left side of the panel is a list of component



collectors (comps). A collector holds related data and allows you to handle the data as one unit. A component collector is a collector that holds element (elems) and geometry (geom) information. Each component collector in this model has been assigned a specific color. Those containing a check mark in the box to the left of the name are displayed for the type of entity defined by the geom/elem toggle.

2. Right mouse click on the name of a collector to de-select it.

Notice that collector’s elements no longer display.

3. Use a left mouse click on the collector name to re-select that collector to re-display its elements.

4. Pick any element displayed in the model using the right mouse button or the left mouse button.

This has the same effect as de-selecting the collector from the collector name list.

5. Click none to de-select all the component collectors.

Although no component is currently turned on, portions of the model are still displayed in the graphics area. This is because we have turned off the element portion of the component collectors.

6. Use the geom/elem toggle to work on the geom portion of the components.

Notice how some of the components are active. The display panel allows you to independently turn on and off the display of both the element and geometry portions of component collectors.

7. Toggle back to elems and click all to bring all the elements back.

Similarly, the display panel allows you to control the display of other types of collectors (entities) that are represented in the graphics area.

8. Click return to leave the disp panel.

Changing visual attributes for elements

The visual (vis) panel controls how elements (and multibodies) look. The vis panel is available only when you use the performance graphics engine.

1. Turn on performance graphics from the macro menu Disp page: on the Gfx: line, click per.

Activating the performance graphics mode with the macro button sets the visual attributes for all elements to hidden line (shaded) with mesh lines.

Note The performance graphics engine can also be set from the options panel, graphics sub-panel.

2. From the permanent menu, click vis to enter the visual panel.

The components appear on the left side of the panel and each has an icon showing the display type. On the right side of the panel is a list of choices. Each component can be displayed differently.

Wireframe Element edges are displayed with

lines.

Hidden Line The element is displayed as a filled polygon.

Hidden Line with Mesh Lines

The element is displayed as a filled polygon with the edges drawn in mesh line color.



Hidden Line with Feature Lines

The element is displayed as a filled polygon with the "feature" edges drawn in mesh line color.

Transparent The element is displayed as a filled

transparent polygon.

For post-processing, you have two options:

Element Color The elements are displayed in

element color even in post-processing panels that use results contouring.

Contours The elements are contoured with the

selected results.

3. Select a new choice.

4. Click all.

Notice the icons for all the components change, as does the display.

5. Select another display type and click on the name of a component.

The corresponding elements have their display type updated in the graphics area.

6. Select one more display type and click on one element in the graphics ares.

Once again, all the elements in the correponding component are updated and the icon next to the component name is also updated to reflect this change.

7. Select the icon for Hidden line with Mesh Lines, .

8. Click all.

9. Click return.

Viewing the model using the model browser

1. On the permanent menu, click the model browser .

2. Look in the macro menu area for the browser display. You’ll see something similar to the figure below.



Model browser.

The model browser allows you to view the HyperMesh model structure by organizing assemblies, components, multibodies, properties, materials, and beamsectcols into a tree-like display. It also combines functionalities from the disp and vis panels.

Components and assemblies have two display states: one for its elements and another for its geometry. You can switch the display mode by clicking the Elems or Geoms radio button on the bottom right of the browser window.

You can also determine which components are displayed by removing the checkmark from the box infront of the component. To remove the check mark, click the check mark in front of the component’s name.

3. Click the check mark infront of end1 and end2 and notice the display.

4. Use the leftmost bottom icon to Display All.

5. Close the model browser, by clicking the x in the upper right-hand corner of the browser window.

Menus and menu items

In this section, familiarize yourself with the various menus and menu items available in the HyperMesh panels. Then experiment with these menu items in the translate panel by translating portions of the bumper model.

Toggles and switches

These icons for toggles and switches appear on some panels and sub-panels.



Toggle: Alternates between two options.

Switch: Presents a pop-up (floating) menu with several options to choose from.

Menu Items

Panels can contain sub-panels or tools. These tools appear as function buttons, toggles, switches, entity selectors, direction selectors, coordinate system selectors, data entry fields, input fields, and pop-up menus. The tools on each panel allow you to specify settings and enter information needed to perform the panel’s function.

Most panels in HyperMesh work from left to right. The left side of the panel contains the information gathering tools for the operation and on the right side of the panel are the action buttons to carry out the operation.

• From the Tool page, select the translate panel to view the menu items described in this section.

Translate panel

Entity selector

The entity selector allows you to choose which type of entity you want to perform a function on. The entity selector may or may not have a switch; some panels perform a function on only one type of entity. The entity selector button is yellow; when it is surrounded by a halo, the selector is active and ready for you to select or pick the entities to be processed.

Entity selector

Direction selector

The direction selector allows you to define a plane or vector by using the global x, y, or z axis; or by selecting a vector; or by selecting nodes in the model. Click the switch to obtain the pop-up menu of available directions.



Direction selector Direction selector pop-up menu

x-, y-, and z-axis These options allow you to specify a direction or plane using the global X Y Z coordinate system.

N1, N2, N3 This option allows you to create a user-defined direction. Selecting two nodes, N1 and N2, allows you to define a vector direction with base point at N1 toward N2. Selecting three nodes, N1, N2, and N3, allows you to define a plane with base point at N1 (unless otherwise specified). The vector is normal to the plane and its direction is determined by the right hand rule.

SettIing vector direction using right hand rule

vector Allows you to use an existing vector to define a direction.

base Defines a point on the plane or the base of a vactor. If a base node is not specified, the N1 node selection is used.



edit Click this button to enter the Node Vector Edit panel. In this panel, you can define or edit the coordinates of N1, N2, and N3 and/or the base node used to define a plane or vector.

reset Clears the node selections.

Input fields

Input fields are used to enter text or numerical values. A description of the type of input precedes the field.

For a numeric input field, you can double click the input field and use the HyperMesh calculator to enter the value.

Pop-up menus

Pop-up menus display when there are several options from which to choose.

The extended entity selection menu allows you to specify alternate methods for selecting entities of the current data type. To use the extended entity selection menu, click the yellow data type button of the entity selector. The menu automatically closes after you have made your selection.

Extended entity selection menu

Function buttons

The color of the menu button corresponds to its purpose:

green Carries out a function or a command.

red Exits a panel or aborts a command.

Secondary menu

Access the Secondary Menu by pressing the function keys, F1 through F12, and Shift F1 through Shift F12. Secondary menu functions temporarily interrupt main panel functions while leaving all settings and selections intact. When the secondary function completes, the initial main panel function resumes.

Translating elements



In this example, use the translate panel to translate elements along a vector and familiarize yourself with using the various menu items in HyperMesh.


1. Click the entity selector switch.

A pop-up menu displays all the entity types you can modify with the translate panel. The mouse cursor is located at the center of the pop-up menu.

2. Select elems to specify elements as the type of entity to translate.

After you select elems, the pop-up menu automatically closes. The yellow entity selector button displays elems and the button has a blue border to indicate it is active.

3. Click elems.

The extended entity selection menu displays. Review the options available.

4. Select by collector, indicating you want to select the elements by component collector.

After you select by collector, a list of component collectors displays.

5. In the graphics area, pick an orange element. Selecting this element also selects the component collector the element belongs to, in this case end1.

The picked element is momentarily highlighted white. The check box preceding end1 has a check mark in it.

6. Click select accept and confirm your selection.

This selects all the elements in the component collector, end1, as the elements to be modified when you use the translate function.

7. Click the direction selector switch and select N1,N2, N3 to use nodes as the means for defining the direction of translation.

8. Click N1.

The N1 button has a blue halo to indicate that it is active. The selected elements in the graphics area display in gray because the entity selector is no longer active.

9. In the graphics area, pick any node.

A green node appears in the graphics area at the node that was picked. The N1 button no longer has a blue halo, but the N2 button does. N2 is currently active.

10. In the graphics area, pick a second node node.

A blue node displays in the graphics area at the node that you specified. N3 becomes active: in this case we choose to define a vector, so no additional node will be selected.

To define the magnitude of translation, use the distance between two nodes.

11. Press the function key, F4, on the keyboard to interrupt the translate panel and jump to the distance panel.

The distance panel displays. By default the active sub-panel is the top two nodes sub-panel. The N1 button has a blue halo to indicate that it is active.

12. Pick two nodes in the graphics area for N1 and N2.



The absolute distance between the two nodes automatically displays in the input field following distance =. To use this value back in the translate panel, you can copy and paste it using CTRL+C and CTRL+V.

13. Click the field next to distance = to make it active and press CTRL+C on your keyboard to store this value in a buffer.

14. To exit the distance panel, click return.

The translate panel re-displays. The elements and the nodes for N1 and N2 selected prior to using the distance panel are still selected.

Warning Returning out of the distance panel would have automatically reset our selections. Using the secondary menus through the function keys allowed us to maintain these selections as we never returned out of the translate panel but simply interupted it.

15. Click magnitude = to make the field active, and press CTRL+V on your keyboard to paste the value from the buffer.

16. Click translate + .

The highlighted elements translate in the direction from N1 to N2.

17. Click translate - .

The highlighted elements are translated in the negative N1-N2 vector direction to their original position.

18. To exit the translate panel, click return.

Database relationships: elements/components/properties/materials

This section of the tutorial introduces key concepts you will need to effectively work with your models. It describes the relationships between key portions of the HyperMesh database.

Elements Each element has two associated variables: a configuration and a type. The configuration tells HyperMesh how to draw, store, and work with the element. The type allows you to define multiple analysis elements for each HyperMesh element.

Collectors All entities within HyperMesh belong to a collector. HyperMesh uses several types of collectors, for the various entity types. Geometry, nodes and elements, are stored into component collectors (comps). Boundary conditions (loads and constraints) are stored into load collectors (loadcols). Other collector types in HyperMesh are more analysis specific, and include such things as system collectors, vector collectors, multibodies collectors, and others.

Components Components are collectors that contain element and geometry data. This allows you to organize and group your data into units on which various function can performed. Operations performed on a component affect all the elements, lines, and surfaces that belong to the component.

Component collectors also retain property and material information about the entities that belong to it. All the elements in a component collector are assigned the same properties and material except when the elements have a property reference. In this case, the elements are assigned properties from the property collector they reference.



Lines, elements, and surfaces cannot exist outside of a component collector. If you have not created a component first, HyperMesh automatically creates a component, auto1, for those entities as they are generated. At the time of creation, a material collector is assigned to the component collector. If this is not done by the user, HyperMesh automatically creates a "dummy" (empty) material collector with the same name as the component collector and assigns it to the component.

Property Property collectors (props) contain property information about 1-D elements and are required only when a model contains one or more of the following elements:

bar2

bar3

gap

joint

masses

rod

spring

After you create a property collector, you can assign the specified properties to new 1-D elements by entering the collector name after property = when you create or update the elements. Properties for all other element types, 2-D or 3-D, are assigned by the component to which the elements belong. A material collector is assigned at the time of creation of a property collector. Similarly to component collectors, when a material is not assigned by the user to the property collector at the time of creation, HyperMesh automatically generates a material collector with the same name as the property collector.

Material Material collectors contain information about the materials in a HyperMesh model. If a model contains any non-rigid elements, then the model should have at least one material collector. You can assign a material collector to a component or property collector by entering the material collector name after material = when creating either one of them.

Setting current collectors, element size and element order

The global panel from the permanent menu allows you to set many global parameters for your HyperMesh session. It is possible, for example, to select a solver template (see Interfacing with solvers), or specify a result file for post-processing analysis results (see File input and output).

With the bumper.hm model loaded (see File input and output):

1. From the permanent menu, select the global panel.

Specify a global element size using the element size = field. Simply activate the field and type in any value. This defines the element size HyperMesh will use for meshing operations unless otherwise specified locally in a given panel such as the automesh panel.

2. Click element size =, enter 20 and push ENTER on your keyboard to accept this value.

The toggle for the element order: lets you specify the order, first or second, for the elements



HyperMesh creates. Using this toggle does not affect the order of already existing elements, but sets the order for element subsequently generated. To change the order of already existing elements, use the order change panel from the 1D, 2D or 3D pages.

3. Use the toggle next to element order: to change the order between first and second.

Finally, the global panel gives you the ability to set the current collectors. Current collectors are the collectors in which new entities are placed as they are created. If no collector exists in the database for the type of entity created, HyperMesh automatically creates a collector and stores the entities in it. By default, the last created collector is the current collector, whether it was automatically created by HyperMesh, or created by the user.

To modify the current collectors, use the page toggle between pg1 and pg2 to find the collector type of interest. Only six types of collectors are available in this panel: components to collect element and geometry information, systcol for coordinate systems, loadcol for boundary conditions, beamsectcol for beam properties, vectorcol for vectors, and multibody for multibody entities. For all the other types of collectors, the creation of the entities they collect is coincident with the creation of the collector itself.

4. Set the page toggle to pg1, click component = and select end1 from the list of component collectors in the bumper model.

end1 appears next to component = in the global panel, and in the header bar as well next to comp:. Any new element or geometry created at this time would go into the end1 component collector and display in the color of this component.

Note For convenience, the header bar lists the current component collector (comp:) as well as the current load collector (loadcol:) for the model.

Interfacing with solvers

The HyperMesh database is solver neutral. In order to define any solver specific information, such as material or element properties, you need to load a solver template. The template defines the interface between HyperMesh and an FE solver. In HyperMesh, there are two places where the solver template can be set: in the files panel, template sub-panel, or in the global panel. Once you are in either panel, the steps for selecting a template are identical:

1. Go to the global panel from the permanent menu, or to the template sub-panel of the files panel.

2. Click load… to launch the windows style file browser.

The file browser shows the contents of the <install_directory>/templates/feoutput/ directory on PC, and <install_directory>/hm/bin/<platform>/templates/feoutput/ directory on Unix.



feoutput directory showing available solver templates

3. Open the optistruct directory, select the optistruct template and click Open.

This loads the selected solver template, and from this point on, entities can be defined in terms of this solver.

Another way to load a solver template is to select the HyperMesh user profile for this solver. The HyperMesh user interface provides tools that support a variety of solvers. To reduces the number of tools to what is useful for a specific solver, solver user profiles are available. User profiles are tailored to include loading a specific template, loading a specific macro menu, renaming panels, removing unused panels or subpanels, and removing, moving, or renaming panel options. A set of standard user profiles is included in the HyperMesh installation. While the user profiles may change the appearance of a panel - they do not affect the internal behavior of each function.

Note Once you select a standard user profile, the appropriate template and macro menu are loaded. You can return to the standard HyperMesh GUI by selecting the HyperMesh profile. The current user profile is displayed on the header bar.

To load a user profile, from the Geom page, click user prof… and select the solver desired from the drop down list.

Creating collectors

The collectors panel allows you to create, review, and edit collectors. A collector is a database entity that collects other entities, grouping together all the data pertaining to that entity and allowing you to handle the data as a group. Before you create an entity in HyperMesh, a collector in which to store the data must exist, whether it has been created by the user, or is automatically generated by HyperMesh. In this section, create a component collector and a material collector.

With the bumper.hm model loaded (see File Input and Output) and the optistruct solver template loaded (see Interfacing with solvers):

1. From any page, go to the collectors panel.

The collectors panel has three subpanel. The create sub-panel is used to create new collectors. Depending on the type of collector and the template loaded, card images to define solver specific information can be assigned to the collectors as they are created. The update sub-panel lets you



modify some collector attributes, and the card image sub-panel lets you assign, review and edit solver card images.

2. Select the create sub-panel.

3. To the right of the label collector type:, click the switch.

A pop-up menu appears with all the available collector types.

4. Select comps from the list.

comps represenents component collectors, which are used for collecting geometry and element data.

Notes The create sub-panel displays fields for card images or dictionaries depending on the type of solver template that is referenced. If a card image template is loaded, or no template is loaded, the panel displays card image related fields. If a dictionary template is loaded, the panel displays dictionary related fields. Card image and dictionary entry fields are used in the same way except that when a card image solver is being used and edit is selected, the card image is displayed in a new area of the screen. For dictionary solvers, the data is shown in the existing menu area. This is how solver specific information can be tied to the HyperMesh entities.

The sub-panel also references a material field. This is where a material collector is assigned to the new component collector. In order to assign a material to a new component as it is being created, the material collector needs to exist or be created first. See Database relationships: elements/components/materials/properties for detailed information on how various collectors are tied together.

Start by creating a material collector. When creating a material collector, you need to set the collectory type to mats, give the material collector a name, indicate if there is a card image to assign to it and what type, and supply the necessary values to specific fields on the card.

5. Click the switch after collector type: and select mats.

6. Click the text box after name = and enter 6061_T6_ALUMINUM.

7. Click the switch under creation method: and select card image =.

8. Click card image = and select MAT1.

This is the card image necessary to create an OptiStruct elastic isotropic material.

9. Click create/edit.

This function, unlike create which would simply create the material collector with the card image attached to it, gives you the opportunity to review the MAT1 card image and type in any values for the various parameters. The MAT1 card image is displayed in the card previewer.

By default, most of the number fields are not active. To activate a number field, click the field heading (in brackets). A text box with a default value opens. Modify the value by over-writing it or if no value has been set, enter a value in the text box.

Warning When creating collectors, it is common to inadvertently click create instead of clicking create/edit. In such situations, clicking create/edit will result in an error message as HyperMesh does not allow for the creation of two collectors with the same name. In order to edit the card image, use the card image sub-panel instead.

10. Click E, type 70000, and press ENTER.

11. Click NU, type .33, and press ENTER.



12. Click return to accept the values.

A material collector named 6061_T6_ALUMINUM is created.

Component collectors (comps) require a name, a material and if a card image is desired, the card image type. Since components are displayed, they also require a color. Field values on the card images can be set at this time as well.

13. Click the switch after collector type and select comps.

14. Click name = and enter bumper.

15. Click the switch under creation method: and select card image =.

16. Click card image = and select PSHELL.

This is the OptiStruct card image that is used to define shell element properties.

17. Click material = and select 6061_T6_ALUMINUM from the list of material collectors.

18. Click color and select color 8.

19. Click create/edit.

The PSHELL card is displayed in the card previewer. Set a value for the thickness.

20. Click T, and enter 3.0.

21. Click return to accept the value.

A component collector named bumper is created.

The same principles would apply to the creation of property collectors, and other types of collectors.


Reviewing and editing card images

The card panel from the permanent menu is used to view and edit database information (card images) in the solver format defined by the output template (see Interfacing with solvers).

With the bumper.hm model loaded (see File Input and Output) and the optistruct solver template loaded (see Interfacing with solvers):

1. Click card on the permanent menu to enter the card panel.

The default setting of the entity selector in this panel is nodes.

2. If it is not currently set, use the entity selector to set the type of entities to nodes.

3. Pick any node in the model by clicking it in the graphics area.

4. Click edit to bring up the card image for the node you selected.

The OptiStruct GRID card image displays. It contains the node ID number and its coordinates. This is the actual information for this node that appears in the FE deck once the model is exported out of HyperMesh to an ASCII file using the OptiStruct template.



OptiStruct grid card defining node coordinates

5. Click return to close the card editor.

6. Set the entity selector to elems and select any one element from the graphics area.

7. Click edit to review the information specific to the element you have selected.

The card image for the element you selected displays. For a 4-noded element, the CQUAD card displays and contains the element ID number (EID), a reference to a property (PID), as well as the ID number of the 4 nodes (G1 to G4) the element builds on.

OptiStruct card image for a 4-node plate element

8. Click return to close the card editor for the element.

In the OptiStruct and NASTRAN formats, the property card for shell and solid elements (PSHELL or PSOLID cards) are assigned to the component collector. To review the PSHELL card for the element selected, we must card edit the component that the element belongs to.

9. Set the entity type to comps, and click comps to bring up the list of the components in the model.

On the CQUAD4 card, the PID field refers to the property by number only. In HyperMesh, the components can be refered to by name or id. To display the id number of the component, along with the name, click the switch next to name on the lower right corner of the panel and choose name(id) for the display format in the component list. This will add the component id number to the listed components in the model.

10. Select the component with the same ID number as the PID number from the element card image reviewed previously.

11. Click edit to bring up the card image.



OptiStruct PSHELL card image

Note the information on the PSHELL card includes a refrence to a material (MID1) and an editable number field to specify the thickness of the shell elements (T) in the component collector. You can edit this thickness value and enter any new thickness.

12. Click the return button to exit the card editor.

13. Change the type of entity from comps to mats (materials).

14. Click mats to bring up a list of materials in the model, and select the steel material.

15. Click select.

16. Click edit to bring up the card image for the material card.

MAT1 card image

The MAT1 card image defines properties for linear elastic materials. In this case, the fields for E (Young’s modulus) and NU (Poisson’s ratio) are activated. Change any of the numbers in the active fields by clicking in the field and then typing in the new value.

If a field is blank and no number field appears, it is inactive. To activate a field, click the field heading.

17. Click field heading RHO to activate the density field.

The default value appears.

18. Click return to close the card editor.

19. Click return to exit the card panel and return to the main menu.

Note The card image sub-panel of the collectors panel is also useful in assigning, reviewing and editing card images for collectors.

Organizing and deleting entities



In this section, learn how to move and organize entities in a HyperMesh database, as well as how to delete them. This section assumes that the bumper.hm file has been loaded (see File input and output)

Organizing the elements into one component

1. From any page, go to the organize panel.

2. Set the entity type to elems.

3. Click elems and select all from the pop-up menu.

4. Click destination = and select end1 from the component list.

5. Click move to move all the elements into the one component.

6. Click return.

Cleaning up the model

At this point, the model contains unneeded geometry, several empty component collectors, and potentially some unused material collector. Delete all this information that is no longer needed using the delete panel.

1. Go to the Tool page and select the delete panel, or use the F2 function key to jump to this panel directly.

2. Set the entity type to lines.

3. Click lines and select all from the pop-up menu.

4. Click delete entity.

A message comfirms the lines were deleted.

5. To identify and delete empty components, set the entity type to comps.

6. Click preview empty.

A message confirms there are empty components. If you wish, click comps to display the list of components in the model. Those with checks are empty.

7. Click select.

8. Click delete entity.

9. To check for unused materials, set the entity type switch to mats.

10. Click preview unused.

A message in the header will return the number of unused materials in the database.

11. Click delete entity if there are any unused materials.


Note Notice the order in which these steps were performed. One of the components, mid1_and_lines, contained geometry lines. Without deleting the lines in the model first, this component would not have shown up in the list of empty components. This would be true for materials as well. Until the components referencing a material are deleted, this material is not considered unused.



This concludes this introductory tutorial. You may discard the model by using the delete model function from the delete panel.

Proceed from here to any other tutorial.

See HyperMesh Tutorials for a complete list of tutorials.

