S3-1 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation SECTION 3 BASICS OF MSC.NASTRAN AND MSC.PATRAN

S3-2 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation

S3-3 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation PATRAN GRAPHICAL USER INTERFACE n The Patran GUI for the Windows and Unix platforms are shown on the following pages. Except for the color scheme and icon arrangements, the two GUIs are basically identical. n The course material will be presented using the Windows GUI.

S3-4 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation WINDOWS GUI

S3-5 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation UNIX GUI

S3-6 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation THE MAIN MENU Menu Bar Tool Bar History Window Command Line Status Icon Static Green indicates Patran is waiting for user input Rotating Blue indicates Patran is performing a process which can be stopped immediately with the abort icon Rotating Red indicates that Patran is performing a process which can not be interrupted Application Icons

S3-7 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation THE MAIN MENU (CONT.) File Save Print Copy to Clipboard Undo - will undo last command Abort - Stops operation in progress Reset Graphics Refresh Graphics Display and Viewing Icons

S3-8 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation THE VIEWPORT Display Mode Current Group Current Viewport Database Name

S3-9 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation APPLICATION FORMS Action Object Method Select Menu (Filter Buttons)

S3-10 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation APPLICATION FORMS (Cont.) Toggle button is an on/off switch Select databox is used to enter data Data insertion can be made by placing the mouse at the desired location, clicking the left mouse button, and typing in the desired data Existing text can be edited... suffix denotes that a subordinate form will open up upon clicking the button Apply causes action to execute Hyphens indicate action can be undone only immediately after its execution Slide bar assigns a value to associated variable Control icon allows the switching between different actions. In this example, the icon can be set to highlight or split. Causes the content of a form to reset back to default values; the default values may be constant or can change

S3-11 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation ENTITY PICKING n Picking is performed in two ways: u Keyboard entry into a databox u Graphical picking with the mouse

S3-12 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation ENTITY ID SYNTAX SyntaxDescription Point 1 2 3Refers to points 1, 2, and 3 Point 1:9:2Points 1 through 9 by 2 Point 1:#All points Curve 1 2, 3/ 4Different forms for delimiters: space,, and / Surface 3.1References an entity associated with a higher order one (i.e. edge 1 of surface 3, that is similar to a curve) Solid 1:10.2Combinations of entity ID syntax is possible (face 2 of solids 1 through 10) [x y z]Square brackets signifies coordinate specification [xn28, 1, 2]Individual coordinates can reference existing entities, such as x = the x coordinate of node 28 [1, zp5, 3] [1, z5, 3] y = the z coordinate of point 5 When a point is referenced the letter p can be dropped [1, 2, -64.0/20.0]Mathematical operations like division are possible to determine the individual components signifies a vector definition {[ ][ ]}Signifies an axis with first point representing the base and the second determining the direction

S3-13 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation ENTITY GRAPHICAL PICKING n Individual and collective entity picking is controlled by the Picking option under Preferences n For Single Entity Picking, a portion of the selected entity must be within the physical limits of the cursor n For Centroid Single Picking, the closest entity to the location of the cursor will be picked n Additional tools are available to aid the process of picking, such as Cycle picking n The Preselection Settings highlight the Entity and Label (ID #) of the entity before you select it

S3-14 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation CURSOR PICKING Single Entity Move the cursor to the entity label/centroid and press the left mouse button Multiple Picking Hold the shift key down and select the entities with the left mouse button Shift

S3-15 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation CURSOR PICKING (CONT.) Ctrl Rectangle Picking (Click & Drag) Polygon Picking Note: To complete your selection double click the left mouse button Click You can also select this icon from the select menu

S3-16 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation Deselect Cycle Picking Move the cursor to the entitys label/centroid and click on the right mouse button Picking an entity underneath another, or that is close to other entities. Once the cycle picking window appears, make the selection from the window. CURSOR PICKING (Cont.)

S3-17 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation MANIPULATING THE MODEL FOR VIEWING Click on one of these icons then drag with the middle mouse button XY Rotate Z Rotate XY Translate Zoom

S3-18 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation PATRAN ONLINE HELP n Two ways to use on-line help u Use the drop-down help menu to get topical help or help via the world wide web u Press the F1 key to get context sensitive help on a form in question

S3-19 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation PATRAN-NASTRAN WORKFLOW AND FILES MSC.Patran MSC.Nastran Solver K u = F n Solve for u Compute strain n Compute stress.bdf.xdb.op2.db.ses.db.jou.f04.f06. log Pre-Processing n Import/create geometry n Create finite element mesh n Apply boundary condition n Apply loads n Create material properties n Create element properties n Submit model to solver Post-Processing n Deformation plots n Stress fringe plots n Reports

S3-20 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation BASIC MSC.PATRAN FILES File ExtensionFile TypeComments.dbDatabaseOne per model.sesSession FileA Session File is opened at Patran start-up and it is closed when you quit MSC.Patran..db.jouJournal FileOne per model. Record of all PCL commands from database creation to present. Concatenated session files. EXTREMELY useful for rebuilding a database.

S3-21 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation BASIC MSC.NASTRAN FILES File Extension File TypeComments.bdfInput FileContains model definition. Popular extensions are.bdf and.dat.f06Results FileThis is the main Nastran output file. It contains the results of your analysis such as displacements and stresses. It is in ASCII format so it can be viewed in any text editor. It also contains warning messages, error messages, and diagnostic messages to help the user evaluate the quality of the analysis results..f04Execution Summary FileContains a time history of job execution..logOperating System Log File.op2Results FileUsed by Patran for post processing..xdbResults FileUsed by Patran for post processing.

S3-22 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation THE MSC.NASTRAN INPUT FILE n The two files which contain the finite element model definition are u The Patran database file u The Nastran input file n The Nastran input file is useful in a number of ways: u Can be viewed and edited in any text editor u Can include comments to document modeling assumptions and changes u Allows the user to add entries which are not supported in Patran u Useful in debugging a model u Text editing is often the most efficient way to make minor modifications to the model. u The MSC.Nastran input file is often the format used to exchange finite element models between users and companies.

S3-23 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation ORGANIZATION OF THE NASTRAN INPUT FILE n The Nastran input file is arranged in five sections. Nastran Statement File Management Section Executive Control Section Case Control Section Bulk Data Section CEND BEGIN BULK ENDDATA Optional Sections Required Sections Required Delimiters ID A,B Optional Delimiter

S3-24 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation NASTRAN INPUT FILE SECTIONS n Nastran Statement – Used to modify system defaults. Not needed in most runs. n File Management Section – Allocates files, controls restarts and database operations n Executive Control Section – Solution type, time allowed, program modifications, and system diagnostics n Case Control Section – Output requests and selects Bulk Data items such as loadings and constraints to be used n Bulk Data Section – Model definition, loadings, and boundary conditions

S3-25 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation NASTRAN INPUT FILE DELIMITERS n The delimiters are u ID A,BFirst statement in Executive Control Section (optional) u CENDEnd of Executive Control Section, beginning of Case Control Section u BEGIN BULKEnd of Case Control Section, beginning of Bulk Data Section u ENDDATALast entry in the input file

SAMPLE MODEL S3-26 E = 30x10 6 psi = 0.3 A = 4.0 in 2 J = 1.27 in 4 NAS120, Section 3, December 2004 Copyright 2004 MSC.Software Corporation

S3-27 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation ID TRUSS,SAMPLE SOL 101 TIME 5 CEND TITLE = SAMPLE INPUT FILE SUBTITLE = TRUSS STRUCTURE LOAD = 10 SPC = 11 DISP = ALL ELFORCE = ALL SPCFORCE = ALL BEGIN BULK $ $ GRID POINTS DESCRIBE THE GEOMETRY $ GRID GRID GRID GRID $ $ TRUSS MEMBERS MODELED WITH ROD ELEMENTS $ CROD CROD CROD CROD CROD $ PROD MAT E6.3 FORCE SPC SPC ENDDATA NASTRAN INPUT FILE OF SAMPLE MODEL Executive Control Case Control Bulk Data Comments start with a dollar sign

S3-28 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation THE BULK DATA SECTION n The Bulk Data Section contains all data necessary for describing a structural model n Each item described in the Bulk Data section is called an Entry n The Bulk Data entries are not required to be input in any order

FORMAT OF BULK DATA ENTRIES n Each Bulk Data entry has a specific pre-defined format and purpose (described in the MSC.Nastran Quick Reference Guide, Section 5) n Shown below is the CROD entry description from the Quick Reference Guide: S3-29 NAS120, Section 3, December 2004 Copyright 2004 MSC.Software Corporation

S3-30 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation FORMAT OF BULK DATA ENTRIES (CONT.) n Each line contains 80 columns n A Bulk Data entry may span multiple lines n There are three data formats u Integer u Real u Character String n Each field in a particular entry has a required data format. See the Quick Reference Guide for the correct format.

S3-31 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation FORMAT OF BULK DATA ENTRIES (CONT.) n Following representations of the real number are numerically equivalent and acceptable to MSC.Nastran: n Real numbers must be entered with a decimal point. Integers must be entered without a decimal point E212.34E E3.1234E3

S3-32 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation FIELD FORMAT n Each Nastran input file line contains 80 columns. There are three field formats for entering data on these 80 columns: u Small Field Format u Large Field Format u Free Field Format

S3-33 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation FIELD FORMAT (CONT.) n Small Field Format u Each line is divided into 10 fields u Each field is 8 columns wide GRID

FIELD FORMAT (CONT.) n Large Field Format u A high degree of accuracy is required in some MSC.Nastran applications. The large field format is used when the small field format does not provide enough significant digits. u An asterisk after the keyword signifies large field format. GRID* *GRID10 *GRID S3-34 NAS120, Section 3, December 2004 Copyright 2004 MSC.Software Corporation

S3-35 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation FIELD FORMAT (CONT.) n Free Field Format u Fields are separated by commas or blanks (commas are strongly recommended) u To skip a field, use two commas in succession u Integer numbers or character strings with more than eight characters cause a fatal error u Real numbers with more than eight characters are rounded off and will lose some precision Example: GRID,10,,7.5,8.6,9.0,,456

S3-36 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation CONTINUATION ENTRIES n Many input entries require more than one line of input n If this is the case, then continuation entries must be used. n Continuation entries may be generated automatically when the entries are in sorted order. The parent entry may be blank in columns (field 10), and the continuation entry may be blank in columns 2-8 (field 1). For small field entries, the first column of the continuation entry may be blank or contain a + symbol. For large field entries, the first column of the continuation entry must contain a * symbol

S3-37 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation CONTINUATION ENTRIES (CONT.) n Input rules u Unless you use automatic generation, a (+) or (*) is required in column 1, field 1 of a continuation entry. The remaining contents in field 1 of a continuation entry must be identical to the entry in field 10 (columns 2 through 8) of the parent entry (or the preceding continuation entry) u Any entry in the first column of field 10 on the parent entry is ignored by the continuation entry u Small field and large field continuation entries may be used together in defining a single data item entry n An example of the use of continuation is shown on the next page

S3-38 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation CONTINUATION ENTRIES (CONT.) n Two methods of entering a MAT8 entry with continuation are shown below: u Method 1 u Method 2 +M101 +M102

S3-39 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation GENERAL INPUT FORMAT RULES n Input data items in fields 1 and 10 must be left justified. Input data in fields 2 through 9 do not have to be left or right justified. n Errors result if data extends beyond its field into another field. n Input data items must not have any embedded blanks. n All real numbers, including zero, must contain a decimal point. n Many fields have default values. If these fields are left blank, the default values will be used (See the Quick Reference Guide).

S3-40 NAS120, Section 3, May 2006 Copyright 2006 MSC.Software Corporation EXERCISE Perform Workshop 3 Editing a Nastran Input File in your exercise workbook.