Report #025921-16-T TECHNICAL REPORT FOR NASA Grant NAG-2-541 NASA Technical Monitor: Alex Woo Institution: Period Covered: Report Author: Report Title: The Radiation Laboratory Department of Electrical Engineering and Computer Science The University of Michigan Ann Arbor, MI 48109-2122 February 1990 - September 1990 John Zapp Examples of Finite Element Mesh Generation using SDRC IDEAS Principal Investigator: John L. Volakis Telephone (313)764-0500

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Table of Contents Page Introduction to IDEAS 1 Pre/Post Processing 2 Mesh Generation 4 Getting Started with IDEAS 6 Mesh Generation 2-D Example Material Properties Mesh Generation 3-D Example Appendix A: Widely Used Global Commands 22 Appendix B: Examples of 2-D and 3-D Meshes 44

Introduction to IDEAS IDEAS (Integrated Design Engineering Analysis Software) offers a comprehensive package for Mechanical design engineers. Due to it's multifaceted capabilities, however, it can be manipulated to serve our needs as electrical engineers. IDEAS can be used to perform the following tasks: ~Solid modeling *System assembly *Kinematics ~Finite element pre/post processing ~Finite element solution ~System dynamics *Drafting ~Test data analysis ~Project relational database Each of IDEAS capabilities is contained in a family. These families, in turn, offer highly interactive, graphics oriented, menu-driven modules. (See figure 1.1). L Family Solid Modeling (I-DEAS Geomod) Engineering Analysis (I-DEAS Supertab) System Dynamics (I-DEAS Systan) Drafting (I-DEAS Geodraw) Test Data Analysis (I-DEAS Tdas) Module Object Modeling System Assembly Mechanism Solution Excitation Definition Response Pre/Post Processing Model Solution Optimization Data Loaders Frame Analysis Component Definition Orthogonality System Assembly Project Documentation Excitation Definition Response Component Loads - single module - - single module - Figure 1.1

Pre/Post Processing As a member of the Engineering Analysis (Supertab) family, Pre/Post Processing allows the user to build finite element models, prepare them for analysis, and display analysis results following the analysis. It is divided into several major areas of functionality, called tasks. (See figure 1.2). Pre/Post Processing -Geometry Definition| Mesh Generation Adaptive Meshing Laminate Modeling Beam Properties. ---..... — Model Preparation Model Checking... Analysis Cases Post Processing. Interfaces Pearl Data Transfer Pearl Data Manage Figure 1.2 Geometry Definition Use the Geometry Definition task to create and manipulate points and curves as the basis for mesh generation. After you create geometry, you can access it in the Mesh Generation task and use it to define the criteria that control automatic mesh generation. This task also allows you to transfer solid object geometry from IDEAS Geomod. Mesh Generation Use the Mesh Generation task to create mesh areas and mesh volumes that control automatic mesh generation. In mesh area, Supertab generates shell elements, and in mesh volumes, solid elements. In each mesh area or volume, you can specify mapped meshing or free meshing. Adaptive Meshing Use the Adaptive Meshing task to redefine mesh areas based on information resulting from a finite element analysis or based on model checking values

The mesh can be adapted with node movement, element splitting, or a combination of both techniques. Result error approximation techniques are also available in this task. Model Preparation Use the Model Preparation task to create nodes, elements, physical property tables, material property tables, coordinate systems, and trace lines. This task also offers the analysis program mask, which allows you to specify the finite element analysis program you plan to use. After you select an analysis program from this menu, Supertab masks all physical and material properties that do not apply to the program you selected. Model Checking Use the Model Checking task to verify your model's validity for analysis. For example, you can use this task to check your model for node coincidence, element coincidence, and element distortion. You can also use this task to calculate your model's bandwidth and wavefront. Post Processing Use the Post Processing task to display and study the results of an analysis, which exist in the model as analysis datasets. This task can generate displays of deformed geometry, contour plots, arrow plots, criterion plots, XY plots, and beam shear-and-moment diagrams. 3

Mesh Generation In Pre/Post Processing, IDEAS offers a complete set of tools for automatic mesh generation, including mapped mesh generation and free mesh generation. Free mesh generation is performed using the Triquamesh algorithm. Both mapped meshing and free meshing can access geometric information in the form of points curves, and surfaces. You can use this geometry to define the mesh generation criteria that Supertab uses in mesh Generation. To create the geometry to be used in mesh generation, you can use one of two methods. The first method utilizes the solid modeling capabilities of IDEAS using Geomod. Once the geometry is created in Geomod, it can be then transfered to the Pre/Post Processing module for manipulation and mesh generation. The second, and more direct method, is using the Pre/Post Processing's Geometry definition task to create points, curves, and surfaces for your mesh geometry. In addition to automatic mesh generation, IDEAS offers an extensive variety of ways to create complex meshes of nodes and elements. Nodes: Single nodes can be created in several ways, you can: *Key in coordinates, with the CREATE command. *Digitize node location, with the DIGITIZE menu. *Generate nodes between nodes, with the BETWEEN_NODES command. *Copy nodes to a new location, with the COPY command. ~Generate nodes at point locations, with the ON_POINTS command. *Generate nodes by reflection existing nodes with the REFLECT command. Elements: Elements can be created using the CREATE menu, and one of the following methods: *Pick nodes to create individual elements with the SINGLE command. ~Copy elements, with the COPY comrmand *Generate elements by reflecting existing elements, with the REFLECT command. *Extrude element faces into solid elements, with the EXTRUDE menu. *Revolve element faces into solid elements with the REVOLVE menu. ~Add a layer of shell elements to a surface of solid elements, with the SURFACE_COATING menu. To generate nodes and elements, Pre/Post Processing processes the information in a mesh-area. A mesh-area is an entity that is operated on by Pre/Post Processing's mesh generation to produce finite elements. A mesharea is topological: it represents a geometric configuration that can be mapped to a parameter space. It does not, however, possess any geometry. The figures geometry must be previously define in order to create a mesh-area. This is due to the fact that a mesh-area is a series of curves that define the closed boundaries of a region to be meshed. 4

Once the geometry of the figure is entered the user must decide which of two types of meshes they require: mapped or free. A free mesh-area can include from three to 100 curves. This mesh-area can describe fairly complicated regions, which can include interior voids, or holes. The user does, however, have control over quite a few specification of the free mesh create. You can: *Define the general size of the elements using the GLOBAL_ELEMENT_SIZE command. *Choose the number of elements per boundary curve by using the ELEMENT_PER_CURVE command. ~Define the size of elements at a point using the LOCAL_ELEMENT_SIZE command. A second type of mesh-area is the mapped mesh area. This is more restrictive than a free mesh-area, because each mapped mesh-area is limited to three or four curves and cannot include interior voids. This curve limitation is not as severe as it might first appear, however, because each curve can be a composite curve. A composite curve is one that you create by merging several simple curves together. By using composite curves, you can model complicated boundaries using only a few curves. Once a mapped mesh area is defined, the users can define how many elements per curve are required. For a body with three sides, all three sides can be defined. For a body with four sides, however, only two adjacent sides can be defined. The computer automatically assigns the other two parallel curves with the same respective values. 5

Getting Started With I-DEAS Follow these instructions to enter I-DEAS: 1. From the operating system, type the command for entering I-DEAS and a <CR>. In our case, on the apollo's, this would be: % ideas <CR> 2. IDEAS asks what type of terminal you are using. To list supported terminals, type M (for "menu") and a <CR>. Typing M lists the entire terminal menu. For our work we will use the terminal type, generic apollo. Enter terminal type# apo <CR> 3. IDEAS clears the screen and asks you for a Model file name. You can type the name of the Model file you created in a previous IDEAS session, or you can type a new name. The Model file name can be at least 7 characters on any operating system; most systems allow more. Do not include an extension to your Model file name; IDEAS supplies this. You can use upper or lowercase. Enter model file name (NONE)# MODEL1 <CR> 4. If you type a new Model file name, IDEAS asks you to verify creating a new file (rather than opening an existing file). Type YES (or a <CR>) to verify a new Model file. The YES contained in parentheses after the prompt means that YES is the default response. You can accept the default response by typing a <CR> only. Y-YES N-NO!-BACKUP $-ABORT New model file OK? (YES)# <CR> 5. IDEAS also asks for the model description for a new Model file. The default is set to the Model file name entered previously. Select it by entering <CR> (description can be up to 80 characters long and can include letters, numbers, and symbols. The description appears in the upper left comer of displays (and hard copies.) Enter model description (MODEL1) Example <CR> 6. The final prompt for a new Model file asks for the system of units you want to use for this Model file. For our Model we will use the default units by entering a <KC>. Enter system of units (METRIC_ABS_(SI)# <CR> 6

7. IDEAS asks what operating mode you want. Your choices are normal operation or program-file operation. Type <CR> to choose the default response, which is normal operation. Program-file operation allows you to collect commands in a program file, or to run a file of commands you have previously collected. Enter operation mode (NORMAL_OPERATION)# <CR> 8. IDEAS asks you what "family" you want. First, wait while IDEAS creates a temporary file. The temporary (scratch) file is where all Model file data is stored. You must enter a SAVE command to copy the temporary files to a permanent database. Then, the product family menu appears. For Mesh Generation, choose Engineering Analysis. This can be done using the cursor by clicking the right mouse button on the screen while the arrow or cross hairs are located on EA, or one can type in the mnemonics, in this case EA. SELECT MENU# EA <CR> 9. IDEAS asks you what module within Engineering Analysis you want. To select a module, type its mnemonic (shown on the left on the menu) or select the menu.with the tablet or mouse cursor. We want to enter the Pre-Post Processing Module for mesh generation. SELECT MENU# P Wait while IDEAS opens the executable for the module you selected. You are now ready to start! 7

About the Mesh Tutorials In the following two tutorials the users can enter the commands in one of two ways. The first is by clicking on the command with the left mouse button when the cursor is located on the command in the menu window. The second method is by typing in the command using its mnemonic symbol. These are displayed in the tutorial in bold, capital print. Note: Only enter what is in bold or capital print. If there is ever confusion with any command entered, there is an appendix with some widely used commands. If the command doesn't appear in the appendix, the user can type HELP (A global command), and a help menu will appear. Continue by clicking on the desired command in either the global menu or current menu. A description of the desired command will appear in the bottom-most right window. 8

MESH GENERATION *An example of Mesh Generation using IDEAS TASK: In this example, we will create the mesh shown in figure 2.10 using the IDEAS Pre-Post Processing module. PREPARATION: Enter IDEAS, create a model file, enter the Engineering Analysis family, and the Pre-Post Processing Module. (See Getting Started). STEP #1: GEOMETRY DEFINITION Our first step in creating a mesh is to define the geometry that we will mesh. SELECT MENU# TAsk SELECT MENU# Geometry_Definiton SELECT MENU# CReate_Wire SELECT MENU# Point SELECT MENU# Position Pick SCREEN_POSITION Key_IN Enter local X,Y,Z (0.0,0.0,0.0)# 10,0 Enter local X,Y,Z (10,0,0.0,0.0)# 0,5 Enter local X,Y,Z (0.0,5.0,0.0)# -10,0 Enter local X,Y,Z (-10.0,0.0,0.0)# 0,-5 Enter local X,Y,Z (0.0,-5.0,0.0)# Done SORC I-OES 4.1: Pr/Post Pocessing DATMALE: NOX VIE: M stared Y( INO Orsl tnniti n 210-G-9 14:44:42 UNITS ON oIrT": No stared lp,1at a: t K Sr Figure 2.1 Now we have created the boundary points of the ojive, (See figure 2.1), use the autoscaling command AU so we can display on the monitor window the points we have just create. This is a Global command. (For help on Global commands type Help and then Global). SELECT MENU# AU SELECT MENU#! (back up to Create_wire menu) SELECT MENU# Arc SELECT MENU# P3 (thru_3_points) Specify start location Pick VISIBLE.C I —AS 4.1:..; ORIa: o stored VIE ITk: GaMtru Oefini tln Pre/Post Processlng 31-JLL-90 11:47:48 UNITS: SI OISAY: No stored OPTIO( Here we want to use the cursor to select our points in order to create an arc. Select the 10,0 point first. Specify intermediate location Pick VISIBLE Select the 0,'5 point with the cursor. Specify end location Pick VISIBLE Select the -10,0 point with the cursor ta1l: 1+'E t.tnatetd Aokm.t: l —1DIOGL S$ L r Figure 2.2 9

Now you have created the upper half of the ojive. (See figure 2.2). procedure to create the lower half of our desired geometry. Exit the Arc entering Done. Next we will define our outer boundary. SOC I-OEAS 4.1: Pre/Post Processing; TUTORI. No stored VIEN Task: sGrOSt in t tiaon Repeat this command by 31-JU-90 11:47:48 OISPLAY: io StId NaO,.tt God — bunsfwr a.1 - Specify start location Pick VISIBLE Done / \. < > - SELECT MENU# /CReate_Wire SELECT MENU# Point SELECT MENU# Position Pick Screen_Position Key_In Enter local X,Y,Z (0.0,0.0,0.0)# Enter local X,Y,Z (f 1.0,6.0,0.0)# Enter local X,Y,Z (11.0,0.0,0.0)# Enter local X,Y,Z (11.0,-6.0,0.0)# Enter local X,Y,Z (- 11.0,-6.0,0.0) Enter local X,Y,Z (-11.0,0.0,0.0)# Enter local X,Y,Z (-11.0,6.0,0.0)# SELECT MENU#! (bacl SELECT MENU# Line SELECT MENU# SIngle_Line 11,6,0,-6 t -11 #,0 t,6 Done kup to C Figure 2.3 (It isn't necessary to enter a coordinate if it is to remain the same as the default value. A comma before the number means that first or X value will remain the same as the previous value.) (See figure 2.3) 'reate_Wire Menu) Pick VISIBLE Select points in pairs, 10,0 to 11,0 first then 11,0 to 11,6; 11,6 to -11,6 and -11,6 to 11,0 and finally -11,0 to -10,0. (See figure 2.4). Continue doing this until we have our inside boundary lines. (See Figure 2.5). Type done when this is completed. We have now completed our geometry. - I-OES 4.1: Pre/Post Processing T: rUTORWI: No stored VI Tnk: Gs tre sf nlteon Moda. 1 Y MWI 31-JUL-90 11:47:4 UNISTS m a Ou oDISPLAY: No staredI,.+,.,d,! ~4L~t I cS-' -OES 4.1: Pr/Post Proesing. stared V1.A:tru Onlition._1:l 1 E 31-JU-90 11:47:48 DISPLAY: M steed.eta aaeCt~ I-C U - A.-w- t vAiml FUR~ * v7 L /\ / L Figure 2.4 Figure 2.5

STEP #2: MESH GENERATION The first step in generating a mesh is defining mesh areas from the geometry. SELECT MENU# /TAsk SELECT MENU# ME (back to main menu, and enter Mesh Generation) SELECT MENU# MA (Mesh Areas) SELECT MENU# CReate Enter mesh-area start label, inc (1,1)# <CR> Ok to use thin shell linear quadrilateral elements# N o Select element family (THIN_SHELL)# <CR> Select element order (LINEAR)# <CR> Select element topology (QUADRILATERAL)# Triangle Enter PHYSICAL PROPERTY TABLE name or no. (1-PHYSICAL PROPERTY TABLE1)# <CR> Ok to use default values to create table? (YES)# <CR> Select material type (ISOTROPIC)# <CR> Enter MATERIAL PROPERTY TABLE name or no. (1-MATERIAL PROPERTY TABEL1)# <CR>* Ok to use default values to create table? (YES) <CR> 3-100 curves required for mesh-area 1 Pick curves Now we must select the curves or lines in this case that border our mesh areas by clicking the mouse on them. This will cause the lines to be highlighted. (See figure 2.6). Once you are done selecting the boundaries of the area, enter Done. Select Curves Pick Visible Done Ok to pick a surface? (NO)# <CR> 3-100 curves needed for mesh area 2 Select the curves for mesh area 2, and repeat the previous procedure for mesh areas 2 through 4. (See Figure 2.7). We have now defined the mesh areas. Next we must define the size of the mesh that we require. SORC I-^ EPS 4.1: Pre/Post Procssing 14-UG-90 14:22:02 SRC I-OEFS 4.1: Pr/Post Processing 14-ALG-90 14:22:02 lTAASE: SNWTS 9P waTs v.ss: lbm so msRd b S^.,t _ _ri-mPiM cs4t 'ow: lw MS.mt: ls t_.y - sr Fi ure 2.6 Figure 2.7 *See note at end of Tutorial 11

SELECT MENU# /MEsh_size SELECT MENU# Free_Meshing SELECT MENU# Global_Element_Size Enter global element length (0.0254)# 1 SELECT MENU# /GEnerate_Mesh Select generation type (SHELLS)# Pick Visible mesh-area <CR> Select mesh-areas 1 and 2 by clicking the cursor around the middle of the mesh area. Enter Done when finished. A mesh should appear on the monitor. Ok to keep nodes and elements? (YES)# <CR> The mesh is now completed. STEP #3: FORMATTING DATA OUTPUT The next step is in getting the data we have just created to a data file we can use. We will create Trace lines so that we know what nodes occur at the boundaries of our geometry. SELECT MENU# TAsk SELECT MENU# MP (Model_Preperation) SELECT MENU# TraceLines SELECT MENU# CReate Enter trace line name or no. (1-TRACE LINE1)# Outer Boundary Pick Visible node Relatedto Selected related entity type (ELEMENT)# CUrve Pick Visible curve Now select the curves that form the outer of them with the cursor. (See figure 2.8). Done when you have finished. rectangular boundary by clicking on each They should become highlighted. Enter Pick Visible curve Done Pick Visible node Done Repeat this procedure for the inner conduction boundary. (See figure 2.9). We are now at our final step, writing out our data file. These files are called universal files. They contain more information in them than we really need. We can, however, control to an extent what we output. 12

SORC I-OES6 4.1: Pre/Post Processng CATAmS: 20ECS VIEW: No stored VE Tr: lht GCratlon 14-IG-90 14: 27:57 OW ITS: M p 5ISF.: b staed SRC IE AS 4.1: Pr/Post Processing ONTOe: 25(ES YIE: no stord VIME Tari: eth Gnoratlon 14-AG-90 14:27:57 OI TS SoPION OISPLAY WNo storvd OPT ~i-d 1:' MiC-D i —actat:d Mit: 1 S L~~~2*.Wf~f~A UIL, 7 I~~ - ~\?t': \r ~' x IK r r~LK/: \ I \? ri \, kx I _ Figure 2.8 Figure 2.9 SELECT MENU# SELECT MENU# SELECT MENU# SELECT MENU# Universal_File ENtityRead/Write OFf_(all) FE_entity_data_sw Enter Finite element entity data switch ON or SELECT MENU# Tracelinedatasw OFF (ON)# Enter Trace line data switch ON or OFF (ON)# <CR> SELECT MENU#! (backup to Universal_File menu) SELECT MENU# Write Enter Universal filename (DEFAULT)# Ok to write new file? (YES)# <CR> <CR> We have now completed our task. To save all of your work on disk enter the SAVE command. To get an output plot of the geometry use the global command HC or hard copy. RC I-OMI 4.1: Pr/Post rocessing AM:: tUeORIe i '; No stavd VY TaZF ntl Mpwrtlcn a.4... 31-JL-90 12:13:32 UNITS;A ON OISPLYW: Nb stard I OGSr mnocl pot:14 1-fE sm.. lm I D I ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ \ Ii I Ii V. ' Figure 2.10 13

*Material Properties If a different material property than the default value is desired, we can modify IDEAS default table for material properties to meet our requirements. Every mesh-area that we create has a material property table. We can, however, create different tables for each mesh area. A material property table consists of a series of around fourteen different properties such as shear strength, elasticity, etc.. We can however simply reassign these to meet our needs by entering our data, epsilon for example, into an elasticity slot. When it is output into the universal file, the data is output as a series of numbers, each representing a property in the table. The data does not include the property name. Therefoe we can read these numbers using our code, assuming we know which ones they are, and use them for analysis. Example: Enter MATERIALS PROPERTY TABLE name or no. (1-MATERIAL_PROPERTY_TABLE1)# MATERIAL# 1 Ok to use default values? (YES)# No From here, enter the property number you would like to assign, and the accompanying value. For example if we needed a mu and an epsilon each with a real and an imaginary part, the first four values of the table would be used. 14

Mesh Generation * A 3-D Example Task: In this example we will create a three dimensional geometry using IDEAS Geomod (See figure 3.1). This geometry will be accessed from Solid Modeling and then transfered to Engineering Analysis where it will be modified using the Pre/Post Processing Module. Our final geometry will then be broken into closed loops call mesh-areas. These mesh-areas in turn will be used to create mesh-volumes which will be automatically meshed by the computer. Preparation: Enter IDEAS, create a model file, and enter IDEAS Solid Modeling family, and Object Modeling module. (See Getting Started. See Solid Modeling tutorial for more information on IDEAS Geomod). Step #1: Geometry Definition SELECT MENU# TAsk SRC I-OES 4.1: PrPostProcessing 20 —90 14:38:02 SELECT MENU# PRofile_2D VTiO:A Ws, 0nA: OP _ON SELECT MENU# CReateprofile Pick 2D or 3D point Key_in Enter X,Y of point (0.0,0.0)#.5,0 Enter X,Y of point (.5,0)# x Enter X,Y of point (.5,0)# 1,0 Enter X,Y of point (1,0)# 1,2 Enter X,Y of point (1,2)# 0,2 Enter X,Y of point (0,2)# 0,1 Enter X,Y of point (0,1)#.5,1 Enter X,Y of point (.5,1)# c SELECT MENU# AU | SELECT MENU# TAsk SELECT MENU# Object_3D SELECT MENU# Create SELECT MENU# Revolve Enter angle about Y (360.0)# 90 Figure 3.1 minimum radius change = 0.0 Enter translation along Y axis, change in radius (0.0,0.0)# <CR> Select edge generation option (PERCENT_OF_CHORD_LENGTH)# <CR> Enter maximum % of chord length deviation (11,0)# <CR> Enter number of sections (4)# <CR> Enter OBJECT color name or no. (11-RED)# <CR> SELECT MENU# STOre Enter OBJECT name or no. (1-OBJECT1)# <CR> SELECT MENU# NM (New model) SELECT MENU# CF (Change family) SELECT MENU# EA (Engineering Analysis) SELECT MENU# P (Pre/Post Processing) SELECT MENU# TAsk SELECT MENU# Geometrydefinition SELECT MENU# CReatewire SELECT MENU# OB (From Object)

SELECT MENU# Get_object Enter WORKING_SET name or no. (1-WORKING_SET1)# <CR> Enter BIN name or no. (1-MAIN)# <CR> Enter OBJECT name or no. (DIRECTORY)# <CR> Enter OBJECT name or no.# 1 SORC I-OE4.1: R Enter curve tolerance (0.00032)# <C R> YaMn: ftWnid tio SELECT MENU# DRaw 1 -SELECT MENU# /View SELECT MENU# RM Enter X,Y,Z degrees (0.0,0.0,0.0)# 25,0,0 SELECT MENU# /LAbel Pick visible point or curve * (all) Pick visible point or curve Done SELECT MENU# COpy_and_orient SELECT MENU# Rotate Pick Visible point or curve Label_range Enter point or curve label range# re/Post Processing 14-AU-90 14:53:50 OISRtY: o tad ON lat e t;d MN s.t 5 1-o: o D ' _ Figure 3.2 Here we will enter a the series of curves C1-C6 and C12-C15. entered individually. When done type D for done. Each one is Pick pivot point Pick VISIBLE Key_in Enter local X,Y,Z (0.0,0.0,0.0)# <CR> Enter local X,Y,Z rotation (0.0,0.0,0.0)# 0,90,0 Pick visible point or curve Done SELECT MENU# AU SELECT MENU# /View SELECT MENU# RM Enter X,Y,Z degrees (0.0,0.0,0.0)# 0,25,0 SELECT MENU# /LAbel Pick visible point or curve * (all) Pick visible point or curve Done SELECT MENU# COpy_and_orient SELECT MENU# Rotate Pick visible point or curve * (all) Pick pivot point Pick VISIBLE Key_in Enter local X,Y,Z (0.0,0.0,0.0)# <CR> Enter local rotation (0.0,0.0,0.0)# 0,0,180 Pick visible point or curve Done SELECT MENU# AU (See figure 3.3) SELECT MENU# /DELete (See Figure 3.2) SORC I-OES 4.1: aOiAS: HELPIt m: No steud VID Tark: GwtmWuinition M1.I- I -fF E I Pro/Post Processing 14-AUG90 15:00:21 UNITS: StO OISIAY: No strd OPTff lated Warkit: 1-MORKINE S Figure 3.3 16

Pick visible point or curve Label_range Enter point or curve label range# Here we will enter the series of curves: C1, C7, C12, C15, C16, C19, C20, C25, C45. Each is entered individually. Type D for done when this is completed. Ok to delete 9 entitie(s)? (YES)# <CR> SELECT MENU# /LAbel Pick visible point or curve * (all) Pick visible point or curve Done SELECT MENU# COpyand_orient SELECT MENU# Rotate Pick visible point or curve Label_range Enter point or curve label range# Here we will enter the series of curves: C3, C17, C14, C18, C4, C13, C5, C36, C2, C35, C39, C32, C37, C34, C48, C50, C38, C33, C47, C46, C49. As before each is entered individually and you should type D for done when you have this is complete. Pick visible pivot point Pick VISIBLE Key_in Enter local X,Y,Z (0.0,0.0,0.0)# <CR> Enter local X,Y,Z rotation (0.0,0.0,0.0)# 0,180,0 Pick visible point or curve Done SELECT MENU# AU At this point we have completed defining our geometry. (See figure 3.4). It is recommended that you save your work so far with the SAVE command. SORC I-OEAS 4.1: Pre/Post Processing 13-AUG-90 14:10:39 HtUSE: HELPIT LITS: SI No sta d VIE DISPLAY: No strd OPTION T:sk: NGor iDfln ttlon E IlFigure 3.4lssociated ikst: I-. MC s Figure 3.4 17

Step #2: Mesh Areas Using the same procedure as in the 2-D mesh example, we will define mesh areas from our geometry. These entities will then be used to define mesh volumes with which the computer will generate a mesh using solid elements. As you can see, our geometry contains eight identical sections or volumes. (See figure 3.4). Our first step is to define the closed looped areas that define each section. There are atotal of 44 meshareas in this geometry. (Note: Some areas are shared by two sections. These areas need to be defined only once.) Use figures 3.5-3.11 to define the first set of mesh areas. Continue using symatry to define all 44 mesh areas. (If you have difficulty selecting a curve, see HELP, SPECIAL_TOPICS, SELECTINGENTITIES or Appendix A). SELECT MENU# /TAsk SELECT MENU# MEshgeneration SELECT MENU# MA (Mesh Areas) SELECT MENU# CReate Enter mesh-area start label, inc. (1,1)# <CR> Ok to use thin shell linear quadrilateral elements# No Select element family (THIN_SHELL)# <CR> Select element order (LINEAR)# <CR> Select element topology (QUADRILATERAL)# Triangle From here take the defaults until IDEAS ask for curve selection. Use the figures 3.5-3.11 for mesh area curve selection. After each sequence of curves entered for a mesh area, enter D for done. Ok to pick a surface? (NO)# <CR> SORC I-O S4.1: Prit. ProctainO 2B -9 14:3 8:58 SC I-E6 4.1: Pro/Pst Procsin 2-s-90 14:36:58 mm 14dviD. Oi surfjiITS:tn OT-.S.: n:OI Wm rS H ISE: 1ijT5RT w ftcv YEN lb stare YEN at" - No s No stored vtNN wtio *vS^_ __'___o -- _,M:: Figure i 35Fire 3 F igure 3.5 Figure 3I. Figure 3.5 ltigure 3.6 18

St| i *', s^ $ i I 9 I/ 0 / r - - ^ 1 ~~ E '> ' w ^ / I ' l i 'V ^J — I s r/- "" s ] tl I~i) i~~~~~y3-*-^~~~~~~~~~~~,~ ".............. Vt ~~~~I u/"\ I i.~~~~~~~~. ~1^l~~~~i I!. ( -.-.-..... _^.-...( I '.i iI ----:/,' 'f, - r i / /r "";. L' i- -;n. I '"-\ \' |.s? | \........! V^ ---ii' ---\11 I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I 0/ h sl~~~~ ~ ~~~~~~ 7 K W) 9 VI~ ~~ ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ bO * \\ I \

Step #3: Mesh Volumes Once you have created all of the required mesh areas, you are ready to create mesh volumes. SELECT MENU# MV SELECT MENU# CReate Enter mesh-volume start label, inc. (1,1)# <CR> Ok to use thin shell linear quadrilateral elements# No From here take the defaults until IDEAS ask for mesh-area selection. Use figure 3.12 to select the mesh-areas in the first volume. There will be a total of eight mesh-volumes, each symetric to the one shown in figure 3.12. SC I-nM 4.1: Pr'P ot PvoCair 2-&G-90 14:36:5 b stre.d M:oArt" o str ^ d Ts*: e~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ntion~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Figure 3.12 20

Step #4: Mesh Generation Our next step is to define the size of our mesh. Once this is completed, a mesh with solid elements can be produced. SELECT MENU# /MEshsize SELECT MENU# Free_meshing SELECT MENU# Global_element_size Enter Global element size (.02542)#.5 SELECT MENU# /GEeneratemesh Select Generation type (SHELLS)# Solids Select mesh-volume Pick Visible Label_range Here enter mesh-volumes 1-8 by number. When done enter D for done. SELECT OPTION# Done_with_preview Ok to continue processing? (YES)# <CR> Ok to keep nodes and elements? (YES)# <CR> You have now completed your 3-D mesh. Enter the SAVE command to store your work. 21

APPENDIX A 22

Widely Used Global Commands SA-SAVE: EX-EXIT: ZM-ZOOM HC-HARD The SAVE command converts the temporary files initialy created by IDEAS when the user enters the program, to permanent files. The EXIT command allows the user to exit the IDEAS program. changes since the last SAVE command will be lost. All: The ZOOM command is used to scale the display so that a rectangular area of the screen, which you define, fills the entire screen. COPY: The HARD COPY command converts the display window to a bitmap file which is written onto the current working directory. This file may be then printed using the prf command once the user is back in the UNIX operation system. AU-AUTOSCALE: The AUTOSCALE command scales the Adisplay so th at the entire model fits on the screen. HE-HELP: The HELP command may be used to find information about any command in the current or global directories. A Special Topics section is also included in the help menu, which contains descriptions on selecting entities, and other topics. 23

I-DEAS Supertab Modeling Tools Creating Entities To create an entity such as a node or element, you use the CREATE command in the menu that is named for the entity you want to create. For example, to create a node, use the NODE menu. In the NODE menu, you will find the CREATE command. A CREATE command is offered by every entity's menu. After you create an entity, you can modify its attributes, using the MODIFY command offered by the entity's menu. For example, after you create a node, you can modify its coordinates or its color. A MODIFY command appears in every entity's menu. Besides modifying an entity, you can also delete it, using the DELETE command in the entity's menu. For example, the NODE menu offers a DELETE command. Other entity management commands are offered in each entity's menu. Selecting Entities for Modeling Operations As you create and work with entities in your model, many commands require you to select the entities on which you want to perform modeling operations. For example, one way to select a group of nodes to modify is to select the nodes associated with select elements. To let you select these nodes, a menu appears that offers this option for selecting nodes. The options in this menu depend on the kind of entities being selected: * Entities other than element free edges and free faces 0 Element free edges * Element free faces Selecting Entities Other Than Element Free Edges and Free Faces The following menu appears when you're prompted to pick entities for an operation (unless the prompt is to pick free edges or free faces of elements): V-VISIBLE L-LABEL RANGE G-CROUP A-ATTRIBUTE S-SCREEN AREA E-ENCLOSED VOLUME R-RELATED TO O-HIGHLIGHT Y-DRAW Z-CHANGE VIEW *-ALL D-DONE!-BACKUP S-ABORT Pick visible (entity) You can select the entities to be modified by first choosing the method you want to use to select them. After you choose a selection method, the program prompts you to enter the necessary information. By entering this information, you select one or more entities to be processed. Next, you can select more entities, using either the same selection method or a different one. The following list describes each method: * V-VISIBLE This option prompts "Pick visible (entity)". Use the terminal's screen picking device to pick entities visible on the screen. 24

I-DEAS Supertab Modeling Tools * LABELRANGE This option prompts "Enter (entity) label range". Enter the label of the entity you want to select. To select a series of entities, enter the labels of the first and last entities in the series plus an increment, if you need an increment other than one. An increment may be positive negative. For example, you can enter 8,2,-6, selecting the entities labeled 8 and 2. * GROUP This option prompts "Enter group name or no.". Enter the name or number of a stored group (including a group from the old stack), the processed group, or the current group. 77 means that you are selecting all the entities of the requested type in the group. For examphi if you are picking elements, all elements in the selected group are selected. * ATTRIBUTE This option prompts "Choose attribute". Choose an attribute from the menu that accompar. the prompt. These are attributes of the entity you want to select. This means you are select all of these entities that share the specified attribute. * SCREENAREA This option automatically selects all the visible entities that appear inside a screen area that you specify. To define a screen area, you can choose one of four methods: D -DIAGONAL POINTS This method prompts for two screen points. These two points will define the corners of a rectangle on the screen. All the entities visible in that rectangle are selected. When you de the second point of the rectangle, you have the opportunity to select or reject the entities which cross the area boundary. If you select P-PART INSIDE, which appears at the oromf for the second point, those entities partially inside the area are selected. IP-INSIDE:POLYGON / OP-OUTSIDEPOLYGON INSIDEPOLYGON and OUTSIDEPOLYGON prompt for 3 to 50 screen points. These points connected to define a polygon. All the entities visible and inside/outside of that polygon ax selected. When you define each point of the polygon, you have the opportunity to select c reject the entities that cross the polygon boundary. If you select P-PART_INSIDE, those entities partially inside the polygon are selected. IC-INSIDE _CIRCLE / OC-OUTSIDECIRCLE INSIDE CIRCLE and OUTSIDECIRCLE prompt for a point that defines a circle center and point to define the circle radius. All the entities visible inside/outside of the circle are selected. When you define the radius of the circle, you have the opportunity to select or reject the entities that cross the screen boundary. If P-PARTINSIDE is selected, those en partially inside the circle are selected. S -SIDE.OF.LINE This method prompts for two points that define a line across the screen. After picking twc points, you are prompted to pick which side of the line from which to select entities. All entities visible on the side of the line you pick are selected. When you define the side of hLr to use, you have the opportunity to select or reject the entities that cross the line. If p.. S-SELECTONLINE, those entities that cross the line are selected. NOTE If dynamic viewing is on, don't rotate or zoom the viewport after you begin defining a screen area (for example, by using dials). 25

I-DEAS SuDertab Modeling Tools NOTE If you're using SCREEN AREA to pick face pressures, the screen area must include the entire element on which the face pressure exists. If the entire element is not within the screen area, the face pressure will not be picked. *ENCLOSED-VOLUME This option automatically selects all entities inside a volume that you define, with respect to model coordinates. All entities in the volume are selected regardless of whether they are visible on the screen. You can choose from three methods to define a volume, listed below. After defining the volume, you are prompted "Ok to include (entities) which cross volume boundary?". This lets you include or reject the entities partially inside the volume. D -DIAGONAL POINTS This method prompts you to pick two model locations. These two points define the diagonals of a volume. If the volume was defined in a cartesian coordinate system, the volume will be rectangular. If the volume was defined in a cylindrical coordinate system, the volume will be cylindrical. If the volume was defined in a spherical coordinate system, the volume will be spherical. CE-CECNTERDELTAS This method prompts you to pick a volume center point and enter the length of the volume in each of the three coordinate directions. CO-COORDINATE MIN MAX This method lets you define a volume by entering the minimum and maximum dimensions of the volume in each of the three coordinate directions. * RELATEDTO This option prompts 'Pick related entity type". Choose a related entity from the menu that accompanies the prompt. This means that you selecting all of these entities related to the entities that you specify. For example, if you are selecting elements, you could pick nodes, so that you effectively select all elements related to the nodes you pick. * HIGHLIGHT This option lets you highlight the entities which you have already selected. For example, if you select 50 nodes by a label range and select O-HIGHLIGHT, these 50 nodes are highlighted on the screen. * DRAW This option is the same as the global DRAW command. If the current display was generated by a SKETCH CROUP command, this option repeats the SKETCH-GROUP command. * CHANCE VIEW This option gives you direct access to the VIEW menu. If the AUTO DRAW switch is on, the display is automatically redrawn. * ALL This option selects all occurrences of this entity type. For example, you can select all elements in a model. * DONE This option terminates the entity selection process. 26

Creating Geometry in the Geometry Definition Task Setting Defaults for Points For points, you can set defaults for the following attributes: Label: number assigned to the next point created. Increment of label: increment used to compute the label of the next point created. Color: color of the next point created. Symbol: symbol used to display the next point created. Generation coordinate system: the coordinate system used to generate points based on a point's location. To set defaults for points, use the DEFAULTS-POINT command in the CREATE WIRE, POINT menu. Setting Defaults for Curves For curves, you can set defaults for the following attributes: Label: number assigned to the next curve created. Increment of label: increment used to compute the label of the next curve created. Color: color of the next curve created. Line style: type of representation used to display the next curve created (solid or dashed). Line weight: thickness of line used to display the next curve created. Order: the order of the polynomial used to compute the next spline created. Start symbol: the symbol displayed at the beginning of the next curve created. End symbol: the symbol displayed at the end of the next curve created. Center symbol: the symbol displayed at the center of the next circle or arc created. Defining points symbol: the symbol displayed at the location of each point used to define the next spline created. The default is NONE. Line length: the method used to define the length of a line. Line length can be: Implied: Line length is set to the value appropriate for the creation method you're using. For some creation methods, this may mean the line length is infinite. From/To: You must specify both end points of the line. The starting point of the line is found by a normal projection from the first point you select (during line creation), to the new line. The ending point is found by a normal projection from the second point you select, to the new line. Infinite: unbounded lines are created. Merge option: how existing curves are handled when you merge curves (delete the old curves, or retain the old curves). Split option: how existing curves are handled when you split curves (delete the old curves, or retain the old curves). ro set defaults for curves, use the DEFAULTS CURVE command in the CREATE WIRE menu. If you use the RESET_DEFAULTS command, all default attributes revert to their orginal status, as when you first opened the new Model file. Creating Points A point is a location in 3D space. Each point is defined by the following attributes: * Number (label) * Symbol used to display the point * Three coordinates that define its location with respect to the work plane active when the poiru was created * Color 27

Creating Geometry in the Geometry Definition Task Each point has a unique definition, because no two points in a working set can have the same number. To create points, use the POINT command in the CREATE WIRE menu. It offers a menu that lets you pick the locations where you want to create points. It offers a menu that lets you choose how you want to create points: POSITION Create points at user-define locations. POSITION offers a menu that lets you pick the locations where you want to create points. I-DEAS offers several options for selecting point locations. For an explanation of these options, see "Using the Entity Selection Menu" in this chapter. BETWEEN POINTS Create points by interpolating between existing points. First, select a set of one or more points; this is called the first master set. Then, select a corresponding second master set of points; for each point in the first set, you select a corresponding point in the second set. Next, enter the number of points you want to generate between each pair of points. Finally, enter a starting label and increment for the points to be generated, and select the coordinate system you want to use to generate the points. ON SURFACE Create points that lie on a surface. First, select the surface on which you want to create points. Then, select the option you want to use for defining point locations: CURSORLOCATION At screen locations on the displayed surface. If the surface is visible in the display, select any location on the surface. At each location, a point is created by projecting the screen location to the displayed surface. PARAMETRIC VALUES At parametric coordinates on the surface. Enter the parametric coordinates (s,t) of the point. Pre/Post Processing creates a point at the surface location defined by the coordinates. SPECIFY XYZ At the XYZ coordinates of the point. Enter the XYZ coordinates of the point. Pre/Post Processing creates a point at the surface location nearest the XYZ coordinates that you enter. ON CURVE Create points that lie on a curve. First, select the curve on which you want to create points. Next, select the locations on the curve at which you want the points to exist. ONNODE Create points that are coincident with nodes. Select the nodes on which you want to create points. REFLECT Create points by reflecting the locations of existing points about a plane. First, select the points that you want to reflect. Then, enter a starting label and increment for the points to be generated. Next, define the plane about which you want to reflect the points. Finally, enter the distance from the plane within which you don't want to reflect points. For example. if you don't want to reflect points that lie on the plane, you could enter a value of 0.001 (assuming other points are less than 0.001 units from the plane). 28

Creating Geometry in the Geometry Definition Task COPY USING CS Create points by copying the locations of existing points and translating the new points. First, select the points you want to copy. Then, enter the number of copies you want to create. Next, enter a starting label and increment for the new points. Finally, select the coordinate system you want to use the generate the points and enter a delta value for each of the three coordinate directions. For example, to copy a point to a new location that's four units away in the x direction, select the cartesian coordinate system and enter a delta value of x=4. Digitizing Points You can digitize point locations from a tablet. To digitize points, use the DIGITIZE menu, located in the CREATE WIRE menu. For more information about digitizing, see "Digitizing Nodes and Points" on page 3-12. Creating Lines A line is a straight curve. You can create two types of lines: bounded and unbounded. A bounded line has a definite length, from one set of coordinates to another set of coordinates. An unbounded line has infinite length. Each line is defined by the following attributes: * Number (label) * Bounded flag * Length (if bounded) * Linestyle * Color * A starting coordinate and ending coordinate, for a bounded line, or two coordinates through which the line passes, for an unbounded line Each line has a unique definition, because no two lines in a working set can have the same number. For most line creation commands, the type of lines created depends on the "line-length mode" in which you're working. You can set the creation mode by using the CURVE-DEFAULTS menu, or you can use the Q-LINE-LENGTH option in the menu offered when you select a line creation method.;- - - ~ NOTE The type of lines created (bounded or unbounded) usually depends on the mode in which you're creating lines. To create lines, use the LINE command in the CREATEWIRE menu. It offers the following ways to create lines: POINT TO POINT Bounded lines, connected end-to-end. Select the starting point; then, select the ending point of the first line. Next, select the ending point of the next line. The ending point of the previous line becomes the starting point of this line. Continue creating lines by selecting the next ending point. For this command, all lines are bounded. You can start a detached line by selecting NEW- LINE-START from the menu offered when you select POINT-TO-POINT. 29

Creating Geometry in the Geometry Definition Task SINGLE LINE Bounded lines. Select the starting point and ending point for each line you want to create. X DIRECTION Lines parallel to the x axis of the active work plane, passing through a location. Select the location through which the line must pass. For this command, the implied mode works like the infinite mode. Y DIRECTION Lines parallel to the y axis of the active work plane, passing through a location. Select the location through which the line must pass. For this command, the implied mode works like the infinite mode. Z DIRECTION Lines parallel to the z axis of the active work plane, passing through a location. Select the location through which the line must pass. For this command, the implied mode works like the infinite mode. VECTOR POINT Lines parallel to a vector. Select the location through which the line must pass; then, define a vector to which you want the line to be parallel. For this command, the implied mode works like the infinite mode. If you use this command to create lines in the infinite mode, you are prompted to select start and end locations through which the line should pass. PARALLEL TO LINE POINT Lines parallel to an existing line, through a point. Select the line to which you want the new line to be parallel; then, select a location through which the line must pass. If you use this command to create lines in the implied mode, the length of each new line is equal to the length of the selected line. If you use this command to create lines in the infinite mode, you are prompted to select start and end locations through which the line should pass. PERPENDICULAR TO LINE POINT Lines perpendicular to an existing line, through a point. Select the line to which you want the new line to be perpendicular; then, select a location through which the line must pass. If you use this command to create lines in the implied mode, the length of each new line is equal to the length of the selected line. If you use this command to create lines in the infinite mode, you are prompted to select start and end locations through which the line should pass. PARALLEL TO LINE AT DISTANCE Lines parallel to an existing line, separated by a user-specified distance. Select the line to which you want the new line to be parallel; then, key-in the distance from the original line to the new line. To specify the position of the new line, you can use either of two methods: VECTOR METHOD You can define a vector from the selected line to the new line. With this method, the new line and the selected line can be on different planes. SIDE ON WORK PLANE You can select on which side of the selected line the new line will be created. With h method, the new line is on the same plane as'the selected line. If you use this command to create lines in the implied mode, the length of each new fine equal to the length of the selected line. 30

Creating Geometry in the Geometry Definition Task If you use this command to create lines in the infinite mode, you are prompted to select start and end locations through which the line should pass. TANGENT THRU POINT Lines tangent to any arc or circle, passing through a user-specified location. Select the arc or circle to which you want the line to be tangent; then, select the location through which the line must pass. At this point, one or two infinite tangent lines are drawn. You can select either of the lines, but not both. The line you select is kept, while the other line is discarded. If you use this command to create lines in the implied mode, the length of each new line passes from the first location you select (the through location) to the tangent location. If you use this command to create lines in the infinite mode, you are prompted to select start and end locations through which the line should pass. TANGENT TO 2 ARCS Lines tangent to any two arcs or circles, or a circle and an arc. Select the two arcs or circles to which you want the line to be tangent. Up to four infinite, tangent lines are drawn, from which you can select one that you want to keep. If you use this command to create lines in the implied mode, the length of each new line passes from a location tangent to the first arc or circle, to a tangent location on the second arc or circle. If you use this command to create lines in the infinite mode, you are prompted to select start and end locations through which the line should pass. Creating Circles A circle is a closed arc. Each circle is defined by the following attributes: * Number (label) * Linestyle * Color * Coordinates of center, with respect to the active work plane * Coordinates of one location through which the circle passes, with respect to the work plane active when the circle was created * Unit normal * Radius Each circle has a unique definition, because no two circles in a working set can have the same number. 31

Creating Geometry in the Geometry Definition Task To create circles, use the CIRCLE command in the CREATE WIRE menu. It offers the following ways to create circles: CENTER_RAD I US Single circle. Select a point and enter a radius. The circle is created in the active work plane (local or global), or in a plane parallel to the active work plane. THRU 3 POINTS Single circle. Select three points through which the circle must pass. Intermediate location / - Ending location Starting location /L ___~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 32

Creating Geometry in the Geometry Definition Task THRU 2 PO I NTS Single circle. Select two locations through which the circle must pass. If both locations lie in the active work plane, the circle is created in the active work plane. If either or both locations don't lie in the active work plane, the locations are used to compute a center location and compute a radius. The circle is oriented in the plane parallel to the active work plane, passing through a center location. ----- Second location First location L I~~~~~.I CENTEREDGE Single circle. Select a center location and a location through which the circle must pass. If both locations lie in the active work plane, the circle is created in the active work plane. If either or both locations don't lie in the active work plane, the locations are used to compute a radius. The circle is oriented in the plane parallel to the active work plane, passing through a center location. 33

Creating Geometry in the Geometry Definitinn Task CENTER 2 POINTS Single circle. Select a center location and two locations through which the circle must pass. If the "through" locations are not equidistant from the center location, the radius is determined by the first "through" location. Center location First location m a^S, ~/S ^^ e Second location CONC CIR CENTER Multiple concentric circles. Select the common center location, then key-in the radius for each concentric circle. The circles are created in the active work plane. Center location First circle -\ f --- — /Concentric circle i_ i i i i i i i i i, l < CONC CIR TO ARC Multiple concentric circles, about an existing circle or arc. Select an arc or circle; then, key-in the radius for each concentric circle. The circles are created in the active work plane. Their common center location is the center of the selected arc or circle. / First circle Concentric circle -^-^y ~ 34

Creating Geometry in the Geometry Definition Task TANGENT THRU POINT Single circle tangent to a curve. Select a curve; then, select a location through which the circle must pass. The tangent location is determined by a normal projection from the "through" location. These two locations are used to compute the center location and the radius. The circle is created in the plane parallel to the active work plane, passing through the center location. TAN TO 2 CURVES Single circle tangent to two curves. Select two curves; then, select a point on one of the curves, to which you want the circle to be tangent. If more than one tangent circle can be created, you can select which circle you want to keep. ~Firj~st~ circle _/Second circle First circleon of tangency Location of tangency l - i -t 35

Creating Geometry in the Geometry Definition Task Creating Arcs An arc is an open curve with a constant radius. Each arc is defined by the following attributes: * Number (label) * Linestyle * Color * Coordinates of center, with respect to the active work plane * Coordinates of the starting location of the arc, with respect to the work plane active when the arc was created * Coordinates of the ending location of the arc, with respect to the work plane active when the arc was created * Unit normal * Radius Each arc has a unique definition, because no two arcs in a working set can have the same number. To create arcs, use the ARC command in the CREATEWIRE menu. It offers the following ways;c create arcs: GENERAL ARC General arc. Select the center of the arc. The result is an arc with a curvature of 45 degrees and a radius of one unit (exception: if the system of units is MM, the radius is 10 units). A menu lets you modify this arc before the arc creation process is complete. THRU 3 POINTS Single arc. Select three locations through which the arc must pass. Ending location Intermediate location, -\ __ Starting location j 36

Creating Geometry in the Geometry Definition Task RADIUS START END Single arc. Enter the radius of the arc; then, select two locations through which the arc must pass. Finally, select the approximate center of the arc you want to place the center of the arc. The resulting arc is constructed in a counter clockwise fashion, relative to the normal vector. Side of arc for center \ ^~~/ o Ending location // / Starting location, ^/- L,L i --- —-----— ~:_________________________.____.____l_ CENTER START END Single arc. Select the location of the center of the arc; then, select the starting point and ending point of the arc. The resulting arc has a curvature that is less than or equal to 180 degrees. If the start and end locations are not equidistant from the center location, the radius is equal to the distance from the center to the start location. + -- Center location Ending location Starting location |t\ f r i xArc L 37

Creating Geometry in the Geometry Definition Task CONC ARC TO ARC Single concentric arc. Select the arc to which you want the new arc to be concentric; then, enter a radius for each new arc. To create the new arc, the center point, plane normal, and sweep angle of the existing arc are used. Original arc ~~~\ \^~ ^ Concentric arc L Creating Splines A spline is a closed or open curve whose shaped is defined by a higher order polynomial. The order of the polynomial is set in the CURVE DEFAULTS menu, located in the CREATE-WIRE menu. Its value can be from three to eight. Each spline is defined by the following attributes: * Number (label) * Linestyle * Color * Coordinates of each location through which the spline passes, with respect to the work plane active when the spline was created Each spline has a unique definition, because no two splines in a working set can have the same number. To create splines, use the SPLINE command in the CREATEWIRE menu. It let you select the locations through which the spline must pass. To create a spline, you can select from three to 251 defining locations. Location through which the spline passes 38

Element Library rhin Shell A thin shell element is shown in Figure 8-13. A thin shell element is available with linear, parabolic, or cubic order. Its topology may be either triangular or quadrilateral. 4 3 3 Linear 1 2 1 2 Ouadrilateral Triantle 6 Parabolic a 4 1 3 1 3 2 2 Ouadrilateral Triangle 9 8 10 A 7 a 6 11 6 Cubic 12 1____4 - -4 Quadrilateral Trianfle Qa&UaumL IanzLc Figure 8-13. Thin Shell Element A thin shell element may have the physical properties shown in Table rial properties, see the Appendix. 8-18. For a listing of mate To create a thin shell element, pick the nodes required to define the element's connectivity, in the sequence shown in Figure 8-13. 39

Universal File Datasets 498 499 500 501 502 503 504 505 509 511 512 520 800 801 802 Cross-Sections Joint System Assembly Status Component - Header System Header System Hierarchy Nodes System Instance Orientations System - Animations Geomod - Auxiliary Function Data System - Rigid Bodies System Markers Object - Points Working Set Header Working Set Curves Working Set Points 499 500 501 502 503 504 505 509 511 512 520 800 801 802 Joint System Assembly Status Component - Header System Header System Hierarchy Nodes System Instance Orientations System - Animations Geomod - Auxiliary Function X System - Rigid Bodies System Markers Object - Points Working Set Header Working Set Curves Working Set Points IDEAS Supertab Datasets: Written Read 15 18 55 56 57 71 82 92 705 706 731 735 743 744 747 748 749 752 753 754 755 756 757 759 760 761 800 801 802 Nodes Coordinate Systems Data at Nodes Data at Elements Data at Nodes on Elements Elements Trace Lines Surfaces Mesh Areas Mesh Volumes Physical Properties Node/Element - Geometry Associativity Supertab Points Supertab Curves Material Properties Associated Element Data Model Header Permanent Groups Case Sets Constraint Sets Restraint Sets Load Sets DOF Sets Ply Properties Laminate Definitions Global Element Length Working Set Header Working Set Curves Working Set Points 15 18 55 56 57 71 82 92 705 706 731 735 743 744 747 748 749 752 753 754 755 756 757 759 760 761 800 801 802 Nodes Coordinate Systems Data at Nodes Data at Elements Data at Nodes on Elements Elements Trace Lines Surfaces Mesh Areas Mesh Volumes Physical Properties Node/Element - Geometry Associativity Supertab Points Supertab Curves Material Properties Associated Element Data Model Header Permanent Groups Case Sets Constraint Sets Restraint Sets Load Sets DOF Sets Ply Properties Laminate Definitions Global Element Length Working Set Headers Working Set Curves Working Set Points 40

Chapter 27. Current Universal File Datasets The following datasets are the current datasets which are processed by I-DEAS. Dataset 15 Universal Dataset Type: 15 Name: Nodes Status: Current Written Written Written Written Read Read Read Written Written written Read Read Read Written Written Read by: by: by: by: by: by: by: by: by: by: by: by: by: by: by: by: I -DEAS I -DEAS I -DEAS I -DEAS I -DEAS I -DEAS I -DEAS I -DEAS I -DEAS I -DEAS I -DEAS I -DEAS I - DEAS I - DEAS I -DEAS I -DEAS Level Level Level Level Level Level Level Level Level Level Level Level Level Level Level Level 4 4 4 4 4 4 4 3 3 3 3 3 3 2.5 2.5 2.5 Frame Supertab Tdas Systan Supertab Systan Tdas Frame Supertab Systan Supertab Tdas Systan Supertab Systan Supertab Revision date: 30-AUG-1987 Record 1: FORMAT(4110,1P3E13.5) Field 1 -- node label Field 2 -- definition coordinate system number Field 3 -- displacement coordinate system number Field 4 -- color Fields 5-7 -- 3-Dimensional coordinates of node in the definition system Record 1 is repeated for each node in the model. Example: -1 15 1 2 100 0 0 0 O 0 0 0 O 8 O.OOOOOE+00 8 5.00000E-01 0000OE+00 0.OOOOOE+00 0.OOOOOE+00 -5.00000E-02 8 1.20000E+01 1.20000E+01 -4.50000E+00 41

Universal File Datasets Dataset 71 Universal Dataset Type: 71 Name: Elements Status: Current Written Written Written Read Read Read Read Written Written Read Read Written Read by: by: by: by: by: by: by: by: by: by: by: by: by: I - DEAS I -DEAS I -DEAS I -DEAS I - DEAS I -DEAS I - DEAS I -DEAS I -DEAS I - DEAS I -DEAS I -DEAS I -DEAS Level Level Level Level Level Level Level Level Level Level Level Level Level 4 4 4 4 4 4 4 3 3 3 3 2.5 2.5 Frame Supertab Tdas Frame Supertab Systan Tdas Frame Supertab Supertab Systan Supertab Supertab Revision date: 19 - NOV-1987 Record 1: Record 2: FORMAT(7I10) Field 1 Field 2 Field 3 Field 4 Field 5 Field 6 Field 7 FORMAT(8110) Fields 1-n -- element label -- fe graphical description id -- fe descriptor id -- physical property table number -- material property table number -- color -- number of nodes on element -- node labels defining element Records 1 and 2 are repeated for each element in the model. Example: -1 71 1 11 2 31 39 19 12 12 32 40 1 13 2 33 41 1 11 1 16 2 34 42 1 15 1 21 1 35 43 1 19 8 20 8 36 44 8 18 8 19 16 37 45 8 17 15 38 46 14 124 9 19 10 -1 42

Current Universal File Datasets Dataset 82 — ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~l l..l.versal Dataset vype: 82;'ae: Trace Lines status: Current tr tten by: I-DEAS rtten by: I-DEAS written by: I-DEAS read by: I-DEAS.ead by: I-DEAS Read by: I-DEAS written by: I-DEAS Read by: I-DEAS Read by: I-DEAS written by: I-DEAS Level Level Level Level Level Level Level Level Level Level 4 4 4 4 4 4 3 3 3 2.5 Supertab Systan Tdas Supertab Systan Tdas Systan Systan Tdas Systan _ _ _ _ Revision date: 19-NOV-1987 Record 1: FORMAT (3110) Field 1 Field 2 Field 3 FORMAT (80A1) Field 1 -- trace line number -- number of nodes defining trace line (maximum of 250) -- color -- Identification Line Record 2: Record 3: FORMAT (8110) Field 1 - nodes defining trace line = > 0 draw line to node = 0 move to node ( a move to the first node is implied) Notes: 1.) MODAL-PLUS node numbers must not exceed 8000. 2.) Identification line may not be blank. 3.) Systan'only uses the first 60 characters of the identification text. 4.) MODAL-PLUS does not support trace lines longer than 125 nodes. 5.) Supertab only uses the first 40 characters of the identification line for a name. Example: -1 82 1 TRACE LINE1 1 -1 5 2 1 3 4 5 43

APPENDIX B 44

un I nunOL. III-OJILL VIEW: No stored VIEW Task: Model Preparation Model: 1-FE MODEL1 UNIIS: DISPLAY: No stored OF AscncOci F-tted Work-cPt- 1-WnPKTK~hk. - - - - - -. -.. - - -- - I I k-J 1,1-%-A F 14 %_Ip II ".~~ - -- --- t, ~r vq- r %I'-LI 1 cn.v-.: CT 'Wii. -., ".._7 -4.S~~~~~~~~~~~~~~~~~~~~i^~~~~~~~~~~~~~~~~~yId x 10~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 1: ~~~~~~~~~~~~~~~~~~~

DATABASE: VIEW Task: Model:,\ I L~UL-nO -. 1.: CYLO: No stored VIEW Mesh Generation 1-FE MODEL1 rpe/rost Process i ng 6-JUL-90 14:10:O UNITS: DISPLAY: No stored OP Ac,-c,-()t,]Atp~ri bnrklzot- llllnDkVThli-....... —......-. - — " - - ----------- -, --- —---—,, --- —-----------— _ ___I____ * I Lt~-i. t A, 'r.u k. j. 1 nUdllM 'l.z - ~~ cr Ijyj= 1.? *'~~ I I_ 1.."l F k -; - - u - - -. - -. -.. - J- -.. -.. - -.. - - - -... -. - - - 0) X tf I'! sm Sr, 1~~~ — Y — ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~.....:.,I.. I 'ry~~~~~" -J T 'r.7r —?-!)r - r -2 'f --- --- -- --:.. r~ '"; )~ ~ i: ~! ~~; ~~~( ~:.1Ji~r i~ ' ".. r*:: ~~ ~~ ~~ r~ ~~ ~ r~ ~~ ~~ I Y L

DATABASE: VIEW: Task: Model: QUAD MESH No sfored VIEW Mesh Generation 1-FE MODEL1 UNITS: DISPLAY: No stored OP Acnn i tHpd Wnr-kcPt- 1 -WnRKTNFr L I. - -- - - -. -. ~~~~~~~~~~~~~I I LJ,%- A U WC I A. I %-II II I V 1 4 L

. - - -.. - %ff%- z DATABASE: OGIVE3D VIEW: No stored VIEW Task: Mesh Generation Model: 1-FE MODEL1 r-,J — UL-,-U 1I. 1. L-. UNITS DISPLAY: No stored OP Associated Workset: 1-WORKING 4: CO I Y

DATABASE VIEW Task: Model: bUKU 1-ULHb. 1:: WINGER: VIEW1 Model Checking 1-FE MODEL1 ere/rost rrocess ng 26-JUL-90 10: 41: UNITS: DISPLAY: No stored OP Acnn ai 'f Wnrkciot 1- i lnDVTMrl,IV', -,.v.,v - I I DvI\r.IVIV

DATABASE VIEW Task: Model: SURC I-UEAS q.1:: MISSILE3D: No stored VIEW Mesh Generation 1-FE MODEL1 Pre/Post Processing 25-JUL-90 10:45:( UNITS DISPLAY: No stored OP ARcnnia ted WnrkPet 1-WflRKTNt; I I %JJw.0A iV %f A 'qw I %.j%. % JL vw -o $ra 0 - I I I I Y

bUKU I-ULHb I.i: DATABASE: 3DMESH#2 VIEW: No stored VIEW Task: Mesh Generation Model: 1-FE MODEL1 pre/Fost Irocess ing 29-JUN-90 11:20:. UNITS DISPLAY: No stored OP Associated Workset: 1-WORKING L

blUKU I-ULHtb '.1: DATABASE: 3DMESH#2 VIEW: No stored VIEW Task: Model Checking Model: 2-FE MODEL2 Pre/Most Process ng 9-JUL-90 14:37:: UNITS DISPLAY: No stored OP Associated Workset: 2-WORKING i

UNIVERSITY OF M\cHIGAN 3 9015 02527 7792 THE UNIVERSITY OF MICHIGAN DATE DUE JAN 041993 4i t!at rlst S/s-( 1:3f b/e /s~S I~~~~~~~~~~~