Introduction

Different Program Versions

There are three different versions of MAKROS:

Makrose.exe/Makros.exe: Independent application (English/German),

Makrosae.exe/Makrosa.exe: ADS application of AutoCAD (English/German),

Makrosarxe.arx/Makrosarx.arx: ARX application of AutoCAD (English/German).

Using makrosarx.exe, data transfer between AutoCAD and MAKROS is much faster.

Functionality

MAKROS is a program for Finite Element Pre- and Postprozessing. It may be started as independent application or as an ARX respectively ADS application to AutoCAD, where it is possible to exchange data between AutoCAD and MAKROS.

MAKROS offers the following functions:

Creation of Finite Element ( FE ) models

The creation is done in following steps:

First, a geometry model is created within AutoCAD or with MAKROS commands. This model uses as few as possible macro elements to approximate the geometry of the given structure. Within these terms „macro element’s“ are large elements whose edges may also be spline curves. All macro elements give the “Macro model” of the structure.

The macro model is transferred to MAKROS if it is created in AutoCAD.

MAKROS specifies the parameters for the subdivision of the macro elements into finite elements.

MAKROS calculates the subdivision of the macro model and creates the finite element model, which may be transferred to AutoCAD.

With further commands of MAKROS this finite element mesh can be logically checked and possibly geometrically modified within AutoCAD or with MAKROS commands.

Additional commands of MAKROS can be used to assign constraints, loads, element properties and material data.

The resulting FE model can be saved in a text file using the neutral PATRAN, the NASTRAN or a special interface specification.

Using command “Load DLL“ it is also possible to invoke own functions for the generation of nodes and elements.

Interface between AutoCAD and other processing tools

MAKROS can also be used to translate geometry data from AutoCAD to other processing tools. AutoCAD data can be read directly from an AutoCAD session or from a DXF-file. AutoCAD entities are translated to line, surface or solid elements. Geometrical data can be checked within MAKROS and possibly be modified by several functions and made available for further processing within simply structured text files. MAKROS can read most entity types from AutoCAD. Blocks and polylines composed of line and curved segments prior must be broken up into basic components by the AutoCAD command „xplode“.

Post processing

MAKROS offers functions for visualization of calculation results received from other FE programs.

Invoking MAKROSARXE, MAKROSAE, MAKROSE

Makrosarxe is loaded as a DLL with the AutoCAD command ARX/Load, the file “makrosarxe.arx” must then be selected in a file selection dialog. The DLL can not be unloaded using ARX/Unload, it remains loaded until AutoCAD is finished. Makrosarxe may also be loaded using the AutoCAD command (arxload “makrosarxe”).

Makrosae is activated with the AutoCAD command (xload “makrosae”). Please note the parentheses which must surround AutoLISP command “xload”. Makrosae can be unloaded with (xunload “makrosae”).

Note: Starting Makrosae or Makrosarxe within AutoCAD using “xload” respectively “arxload”, AutoCAD needs the location of the executables and menu definitions of MAKROS. The directory of these files must be added to the support path of AutoCAD (see AutoCAD menu Options/Preferences/Environment/Support).

Makrose.exe can be started as a stand alone application, also it can be associated with several file types and so it can be easily started by double clicking the relevant file name. Supported file types are:

*.dem: Demo files for automated run,

*.mes: Binary macro element structure is loaded and displayed,

*.fes: Binary finite element model is loaded and displayed.

Commands, switching control between AutoCAD and MAKROS

The invocation of commands within MAKROS is done by selecting menus on the menu bar of MAKROS.

Each command consists of a single keyword only. After command invocation an associated dialog box pops up where additional parameters can be specified. By pressing button “Help” within a dialog box, the user can become detailed information about the command.

Execution of the command is started by pressing button “OK”, pressing button “Cancel” will leave the command without execution.

Messages of MAKROS are displayed within the protocol window of MAKROS. Popup windows are brought up if yes or no answers of the user are required.

If MAKROS (makrosae or makrosarxe) is loaded from within AutoCAD, the control of the process is either within AutoCAD or within MAKROS and only commands given in the currently active program are executed. With the menu commands “MAKROSA” (“m_makrosa” in the command line of AutoCAD) respectively “AutoCAD” can be switched between both programs. Giving the command “MAKROSA” (“m_makrosa”) within AutoCAD, the menu bar within the MAKROS window will be shown. Commands have then to be selected only within this menu. All commands given within AutoCAD are delayed. After invoking the command “AutoCAD” within the menu of MAKROS, this menu bar will be hidden and following commands only can be given within AutoCAD.

Loading makrosae from AutoCAD, the menu bar of AutoCAD is automatically expanded by the menu group „MAKROSA“. Loading makrosarxe the command “m_makrosa” must first be given in the command line of AutoCAD, then control is transferred to MAKROS and the dialog box of the AutoCAD command “menuload” pops up, where the AutoCAD menu file “makrosa.mnc” must be loaded and the menu group “MAKROSA” added to the menu bar of AutoCAD.

The menu group “MAKROSA” has only the menu point “MAKROSA” that invokes the command “m_makrosa” to transfers control to MAKROS.

Programming interface

The functionality of MAKROS may be expanded by own functions. These functions must be provided in one or more DLLs. The commands DLL-Function (see chapter “Commands to generate new nodes and elements” ) and Interface (DLL) (see chapter “Interfaces to FE-Programs” ) allow to call functions from DLLs. Folder “makrosa/dll” contains some examples for the development of DLL functions.

Graphical output, OpenGL display lists (layers)

Graphical output is done within a separate graphics window of MAKROS.

Element models can also be transferred to AutoCAD and displayed or modified within the active AutoCAD view.

The following information can be visualized:

currently defined macro model

currently defined finite element model

external element ID’s, group ID’s, mechanical type ID’s, orientation of the elements etc

specified subdivision of the edges of the macro elements

external ID’s of the nodes

boundary conditions and loads of the finite element model

distribution of scalar based results

distribution of vector based results

simulation of dynamically oscillations

The element model can be displayed as a wire frame model, a wire frame model that shows only sharp edges and as a surface model. The surface model can be rendered and shaded. Parts of the model can have different colors and can be displayed in different layers.

Graphics of MAKROS uses OpenGL functions of Windows NT and Windows 95 where parts of the graphics are internally stored within display lists. The use of such display lists makes it possible to vary aspects of the current view dynamically without a new calculation of the graphics. This way a high performance in the graphics display can be achieved.

Analogous to the notations within AutoCAD we’ll use within the following sections the term „layer“ also for these OpenGL display lists. You can assign different layer IDs to different parts of the structure and names to these layer IDs, so structural parts can easily be identified by name. In case a structure is read from AutoCAD all layer information and layer colors are maintained. The assignments of layers and layer names will also be saved to hard disk.

In case the structure is plotted within several layers, it’s also possible to show or hide these layers within OpenGL.

For the definition of the 3D views within the OpenGL window two dialog boxes are available. With sliders rotation and zooming of the structure can be done quickly.

Note: For OpenGL graphics the color palette should be set to „True Color“ (see Windows menu Display/Settings/Color Palette).

Filenames

Saving the data to hard disk (command “Save”) uses several files with fixed extensions. These extensions are:

*.mes: binary file of the macro model

*.mut: binary file with the data to subdivide the macro elements

*.fes: binary file of the finite element model

*.efp: ASCII-file with node coordinates

*.efe: ASCII-file with element descriptions

*.lqd: binary file with loads, constraints, element properties and material data

*.pos: binary file with post processing data

*.ews: saving of element selection sets

*.btx: saving of text blocks

*.dem: demo files

When a filename is required, a file selection window pops up where an existing file can be selected or a new filename can be given. The basis name of this given filename is only used, the filename extension is automatically appended according to the data being saved. Only files with appropriate extension are shown in the file selection window.

Automatically saving of all data

With the command „Save automatically“ a time increment and a basis name of the files for automated saving can be given. The basis name is appended by _1 respectively _2 and the filename extension according to the type of data being saved. Data is saved alternately in files with expansion _1 respectively _2, so always two copies of different times are available. Saved are the macro model, the finite element model, subdivision parameters and load data that is currently in memory. In case of a mistake, you should turn of the automatically saving immediately, so that a correct saving is not overwritten.

Parameters are to be given in the following dialog box:

Change file title: In a file selection box the basis name of the files is to be specified

Time increment: The time increment for automated savings is to be given in minutes. The time of the latest saving is displayed in the dialog box.

Switch on: Automatically saving is switched on.

Switch off: Automatically saving is switched off.

Undo function

Most dialogs, that generate new nodes and elements, have an „Undo“ button. Recently generated elements are plotted in yellow and can immediately be deleted by clicking this button, this has to be done before any other operation is given

Element selection

Commands, that influence only some elements have the following options for the element selection in the corresponding dialog box of the command:

All: All elements are selected

Group ID: The elements, that have the group ID given in the input field are selected. If two group IDs are given, these are interpreted as min- and max ID of an array of group IDs. If more than 2 IDs are given, these are interpreted as individual IDs.

S1, S2, S3: The element selection stored in selection sets S1 – S3 are used.

Select graphically: Clicking this option, you can select elements graphically with cursor.

New selection: Clicking this button, the dialog box for the element selection is popped up where other options for element selections are given.

Plot: Selected elements are marked with a symbol, so you can check the selection graphically.

Graphical selection of nodes and elements within OpenGL

Several commands have options for selecting nodes and elements graphically within the OpenGL graphics window.

After selecting such an option all graphically selectable nodes respectively elements are marked by a colored symbol. This symbol has then to be selected by cursor.

The graphical selection offers following methods, the cursor symbol indicates which method is active.

Select individual nodes ( key e ): Multiple nodes can be selected by clicking the left mouse button. Selection will be ended by pressing right (or middle) mouse button or pressing the key r respectively p to alter the selection method. The cursor symbol is a square.

Rectangular area ( key r ): Opposite corners of a rectangular area should be marked. All nodes within this area are selected. The cursor symbol is a corner.

Polygon area ( key p ): All the vertices of a polygon area have to be marked with the left mouse button. Pressing right button or the keys e respectively r closes the polygon. The polygon is plotted. All nodes within this polygon are selected. The cursor symbol is a rubber band line.

During a single selection process several individual nodes or nodes belonging to distinct rectangular areas or polygon areas can be selected. The selection is ended by pressing the right mouse button.

The kind of selection can be altered during the selection process by pressing one of the following keys:

e: Change to selection of individual nodes

r: Change to selection of rectangular areas

p: Change to selection of polygon areas

Key input during the selection process will be recognized only when input focus is within the graphical window.

When selecting individual nodes the view can be varied before each selection. If there are more than one selectable point in the square area around the pointer in case of wire frame plot, this point is used that is nearest to the cursor position. In case of hidden surface plot, there may be some invisible points near the pointer, therefor in this case, the point is used that is nearest to the camera position. Note: If there is no visible point in the square, an invisible point may be selected. With hidden surface plot only selection of individual points is allowed.

All selected nodes are marked by a colored symbol. In case of selecting a node by mistake this selection can be made undone by immediately pressing key d when the cursor is within the graphics window and the graphic window has input focus.

In case of a graphical selection is made active from within the dialog box for node or element selection the height of the square area around the pointer can be specified within pixel units in a pop up window.

External node and element Ids, Node elements

Node and elements get automatically an ID continuously as the are defined. Using command Sort Ids can explicitly assigned to nodes and elements. For the assignment of loads, restrictions and properties, the external Ids are used, for that reason it is preferable to use only Ids continuously beginning by 1, so that Ids can directly be used as indices. A not continuos succession of Ids is created, if some nodes or elements are deleted. By saving the data to a disk file, it is checked whether nodes and element Ids are continuously beginning by 1. If this is not the case, a warning is shown in the protocol window. Changing the Ids using command Sort it is checked whether a load file exists and it is asked whether the used Ids in this file should be adjusted.

For the definition of elements first nodes must be defined, to these nodes automatically a node element is assigned because nodes can only be stored in connection with elements. These node elements must explicitly be deleted if they are no longer needed. Saving the file to disk it is checked whether node elements exist and a warning is shown.

Demo files, Tutorials

Command sequences of MAKROS can be recorded to a file and later be reused for demonstration purposes. These demo files use the extension *.dem.

Several demo files are given on the installation CD and can be used as tutorials. Running these demos all dialogs associated with the invoked commands may also be shown with currently used parameter values. To get more details look up command „Demo file“ in the last chapter.

Demo installation

MAKROS will be periodically checked against an available license code provided by a dongle. In case there is no such dongle available, all the functions of MAKROS can be used without any restrictions, however no saving of files or transferring of data to AutoCAD is possible.