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Презентация была опубликована 2 года назад пользователемТимур Юдкин

1 S5-1 PAT318, Section 5, March 2005 SECTION 5 GEOMETRIC MODELING

2 S5-2 PAT318, Section 5, March 2005

3 S5-3 PAT318, Section 5, March 2005 BASICS & DEFINITIONS

4 S5-4 PAT318, Section 5, March 2005 MSC.PATRAN combines topological structures to define geometry The topological entities within MSC.PATRAN are Vertices hold positions for an edge, face, and body All topological entities can be cursor selected to perform MSC.PATRAN functions (e.g. Surface 10.2) TOPOLOGICAL STRUCTURES Vertex Edge Face Body

5 S5-5 PAT318, Section 5, March 2005 CASE STUDY: TOPOLOGY OF SIMPLE SOLID Create a 1x1x1 blue parametric solid Click the Geometry Applications button. Set Action/Object/Method to be Create/Solid/XYZ. Apply. Turn on the solid labels using

6 S5-6 PAT318, Section 5, March 2005 Your model should now appear as follows Solid 1Exploded View Look at topological definition CASE STUDY: TOPOLOGY OF SIMPLE SOLID

7 S5-7 PAT318, Section 5, March 2005 Display Point and Solid labels To display the labels, click on the following icon CASE STUDY: TOPOLOGY OF SIMPLE SOLID

8 S5-8 PAT318, Section 5, March 2005 First, look at how the solid faces are topologically labeled Solid 1.2 Solid 1.4 Solid 1.6 CASE STUDY: TOPOLOGY OF SIMPLE SOLID

9 S5-9 PAT318, Section 5, March 2005 Next, look at solid edges, e.g. Solid In this example six solid edges are picked CASE STUDY: TOPOLOGY OF SIMPLE SOLID

10 S5-10 PAT318, Section 5, March 2005 GEOMETRY BUILDING BLOCKS Point (Cyan) A point is a 0 dimensional CAD entity. It represents a location in space. MSC.PATRAN creates points automatically when constructing curves, surfaces, and solids Points are created at vertices, e.g. surface vertices (corners) It is not always necessary to construct entities starting with their points, e.g. surface from points X Y Z 9 Y Z X

11 S5-11 PAT318, Section 5, March 2005 GEOMETRY BUILDING BLOCKS (Cont.) A curve is a general vector function of the single parametric variable 1 ; it can have many types of mathematical forms: Curve (Yellow) (X,Y,Z) = function ( ) A curve has: Two points, with one at each end A parametric coordinate ( 1 ) whose domain is from 0.0 at P1 (its origin) to 1.0 at P2 Meshed with bar elements P2 P1 P( ) Z Y X Z X Y 5 5 Bar Element

12 S5-12 PAT318, Section 5, March 2005 GEOMETRY BUILDING BLOCKS (Cont.) Surface types can be simple (green) or complex/general (magenta) A simple surface is a general vector function of the two parametric variables 1, 2 : Surface (Simple or Complex) (X,Y,Z) = function ( 1, 2 ) A simple surface has: 3 or 4 bounding edges A parametric origin and parametric coordinates whose domains are from 0 to 1 A simple surface with 3 visible edges has a fourth edge that is degenerate 12P2 P1 P4 P3 Z Y X Z X Y P( )

13 S5-13 PAT318, Section 5, March 2005 GEOMETRY BUILDING BLOCKS (Cont.) Simple Surface n A simple surface can be meshed with either the IsoMesh (mapped) or Paver (free) meshers Display line for visualizing surface Surface 1 IsoMesh Mesh of Surface 1 Nodes follow curves of constant parametric value 1 2 1/3 2/3 Curve of constant parametric value Curves From Surface 1

14 S5-14 PAT318, Section 5, March 2005 GEOMETRY BUILDING BLOCKS (Cont.) Complex Surface A complex or general trimmed surface (magenta) has more than 4 edges (N-sided) and can have inner boundaries Not defined parametrically, e.g. 1, 2 not used It is a trimmed parametric surface Must be meshed with the Paver mesher Meshes perimeter of surface first General Trimmed Surface (8 edges) Paver Mesh of Surface Perimeter of surface

15 S5-15 PAT318, Section 5, March 2005 Y Z X GEOMETRY BUILDING BLOCKS (Cont.) Solid (Simple or Complex) Simple or parametric solid (blue) Vector function of the three parametric variables 1, 2, 3 A simple solid has: 4 to 6 bounding faces Parametric origin and coordinates whose domains are from 0 to 1 A simple solid with 4 to 5 visible faces has some degenerate faces Parametric solids are meshed with the IsoMesh (mapped) mesher to generate hex, wedge, or tet elements P 8 P 7 P 6 P 4 P 3 P 2 P 1 P 5 P

16 S5-16 PAT318, Section 5, March 2005 Tetrahedral Mesh B-Rep Solid GEOMETRY BUILDING BLOCKS (Cont.) Complex Solid Complex or non-parametric solids (N-faced) (white) Non-parametric solids can be either Patran native B-Rep (boundary representation) or parasolid B-Rep CAD solids can be accessed as Patran native B-Rep or parasolid B-Rep solids, and can be meshed using the automatic TetMesh algorithm Meshes faces with tri-s, then perimeter of solid with tet-s first Similar to Paver mesher

17 S5-17 PAT318, Section 5, March 2005 Plane Vector GEOMETRY BUILDING BLOCKS (Cont.) Planes, Vectors Infinite planes and vectors are used for certain geometric operations, such as solid break by a plane A plane is uniquely defined by vector representing its normal and a point on the plane A MSC.PATRAN vector quantity is defined by a magnitude, a direction and a point of origin

18 S5-18 PAT318, Section 5, March 2005 IMPORTING AND EXPORTING GEOMETRY

19 S5-19 PAT318, Section 5, March 2005 FILE IMPORT OPTIONS

20 S5-20 PAT318, Section 5, March 2005 FILE IMPORT OPTIONS (Cont.) Geometry kernel type CAD part Standard format

21 S5-21 PAT318, Section 5, March 2005 CATIA CAD MODEL IMPORT n Several types of CATIA files can be imported u CATIA V4 Model: model file, e.g. dogbone.model u CATIA V5 CATPart: part file, e.g. catbone.CATPart u CATIA V5 CATProduct: product file, e.g. crockbone.CATProduct u CATXPRES File: output file, e.g. otherbone.cat

22 S5-22 PAT318, Section 5, March 2005 CATIA CAD MODEL IMPORT (Cont.) n CATIA V4 Model, CATIA Options include u Import to Parasolid: Yes l Imported geometry will be parasolid type geometry l Import NoShow Entities: Yes n CATIA V4 entities classified as NoShow will be imported l Entity Layers n All layers, or selected layers, are imported l Trimmed Surface Type n Select simple (4 edges) or general trimmed l Group Classification n Displays dialog box for directing entities to MSC.Patran groups l Create Groups from Layers n Creates MSC.Patran groups from CAD layers automatically u Group name: prefix_Ln CATIA V4 Model

23 S5-23 PAT318, Section 5, March 2005 CATIA CAD MODEL IMPORT (Cont.) n CATIA V4 Model, CATIA Options include u Import to Parasolid: Yes (continued) l Sew Sheet Bodies n PATRAN Sew: sew sheet bodies using MSC.Patran software n Verify Boundary: similar to Geometry: Verify/Surface/Boundary l Equivalence Edge Vertices n Equivalence vertices during import l Save Transmit File n Save parasolid xmt transmit file created during import CATIA V4 Model (Cont.)

24 S5-24 PAT318, Section 5, March 2005 CATIA CAD MODEL IMPORT (Cont.) CATIA V4 Model (Cont.) n CATIA V4 Model, CATIA Options include u Import to Parasolid: No l Imported geometry will not be parasolid type geometry, but SGM geometry (MSC.Patran native Solid Geometry Model) l Entity Layers n All layers, or selected layers, are imported l Group Classification n Displays dialog box for directing entities to MSC.Patran groups l Create Groups from Layers n Creates MSC.Patran groups from CAD layers automatically u Group name: prefix_Ln

25 S5-25 PAT318, Section 5, March 2005 CATIA CAD MODEL IMPORT (Cont.) CATIA V5 CATPart n CATIA V5 CATPart, CATIA Options include u Import to Parasolid: Yes l Imported geometry will be parasolid type geometry l Attribute Types l MSC.Patran will create a string attribute and attach it to geometry associated to CATIA V5 publication and/or feature l Entity Layers n All layers, or selected layers, are imported l Trimmed Surface Type n Select simple (4 edges) or general trimmed l Group Classification n Displays dialog box for directing entities to MSC.Patran groups l Create Groups from Layers n Creates MSC.Patran groups from CAD layers automatically u Group name: prefix_Ln

26 S5-26 PAT318, Section 5, March 2005 CATIA CAD MODEL IMPORT (Cont.) CATIA V5 CATPart (Cont.) n CATIA V5 CATPart, CATIA Options include u Import to Parasolid: Yes (continued) l Sew Sheet Bodies n PATRAN Sew: sew sheet bodies using MSC.Patran software n Verify Boundary: similar to Geometry: Verify/Surface/Boundary l Equivalence Edge Vertices n Equivalence vertices during import l Save Transmit File n Save parasolid xmt transmit file created during import

27 S5-27 PAT318, Section 5, March 2005 Two buttons Pro/ENGINEER CAD model import Direct Mesh for meshing Pro/ENGINEER solids Import to Parasolid: create parasolid or not Part: individual part; need license Assembly: set of parts; need license Primitive Geometry: created from CAD import into MSC.Patran; no license needed PROENGINEER CAD MODEL IMPORT

28 S5-28 PAT318, Section 5, March 2005 ProENGINEER Options include Entity Types Curve Surface Solid Trimmed Surface Type Select simple (4 edges) or general trimmed Group Classification Displays dialog box for directing entities to MSC.Patran groups Sew Sheet Bodies PATRAN Sew: sew sheet bodies using MSC.Patran software Verify Boundary: similar to Geometry: Verify/Surface/Boundary Equivalence Edge Vertices Equivalence vertices during import PROENGINEER CAD MODEL IMPORT (Cont.) PROENGINEER OPTIONS

29 S5-29 PAT318, Section 5, March 2005 PROENGINEER CAD MODEL IMPORT (Cont.) DIRECT MESH Use Direct Mesh to mesh Pro/ENGINEER solid in Pro/ENGINEER environment Pro/ENGINEER is executed Geometry is accessed in Pro/ENGINEER through its API Meshing is done using Direct Mesh Resulting mesh is read into MSC.Patran Must have Pro/ENGINEER installed, and have the MSC.Nastran preference in MSC.Patran

30 S5-30 PAT318, Section 5, March 2005 UNIGRAPHICS CAD MODEL IMPORT Set Unigraphics as the Source Select desired UG part file Optional filtering (Unigraphics Options…) of entities is available based on entity type (e.g. Sheet Body), MSC.Patran groups from CAD layers, if sewing is to be done, etc.

31 S5-31 PAT318, Section 5, March 2005 Unigraphics Options include Entity Types Wire Body – curve Sheet Body – surface Solid Body – solid Entity Layers All layers, or selected layers, are imported Attribute Import Displays an attribute dialog box with options for import Create Groups from Layers Creates MSC.Patran groups from CAD layers automatically Group name: prefix_Ln Assembly Import Dialog box displayed for selecting what parts of an assembly are to be imported UNIGRAPHICS CAD MODEL IMPORT (Cont.) UNIGRAPHICS OPTIONS

32 S5-32 PAT318, Section 5, March 2005 n Unigraphics Options include (continued) u Sew Sheet Bodies l Unigraphics Sew: Unigraphics sheet bodies may be modified on import to enable Unigraphics software to eliminate gaps between adjacent surface edges l Verify Boundary: similar to Geometry: Verify/Surface/Boundary UNIGRAPHICS CAD MODEL IMPORT (Cont.) UNIGRAPHICS OPTIONS

33 S5-33 PAT318, Section 5, March 2005 EXPRESS NEUTRAL FILE Express Neutral files are intermediate files that are created during a specific CAD model access, i.e. UG Express Translation, CATIA Direct Express Neutral files are portable when created as text files Express Options provide capabilities such as filtering entities, group creation, model preview

34 S5-34 PAT318, Section 5, March 2005 IGES FILE IGES format Supports Point All curve types All surface types, except MSC.Patran composite B-rep solid

35 S5-35 PAT318, Section 5, March 2005 MSC.PATRAN DATABASE ACCESS MSC.PATRAN database content can be transferred between different databases Import option allows the specification of entity type, ID offset, name prefix, and conflict resolution tools Equivalence Option allows common entities in the databases to be equivalenced Preview option provides access to summary information

36 S5-36 PAT318, Section 5, March 2005 MSC.Patran databases can be accessed by selecting MSC.PATRAN DB as the source MSC.PATRAN DATABASE ACCESS (Cont.)

37 S5-37 PAT318, Section 5, March 2005 Importing options (MSC.Patran DB options) controls Which entities to import Specification of entity ID offset. Specification of unique names, e.g. prefix for group names MSC.PATRAN DATABASE ACCESS (Cont.)

38 S5-38 PAT318, Section 5, March 2005 MSC.PATRAN DATABASE ACCESS (Cont.) Merged finite element and geometry models may be equivalenced-Equivalence Nodes/Geometry Options on how MSC.PATRAN will deal with Discrete FEM Fields (discussed later) on import

39 S5-39 PAT318, Section 5, March 2005 MSC.PATRAN NEUTRAL FILE n MSC.Patran 2.5 neutral file u Geometry l Parametric cubic geometry only, e.g ParametricBiCubic u Finite elements l Nodes, elements l Material and element properties l Loads and boundary conditions u Neutral File convention can be selected under Geometry Representation in Preferences / Geometry

40 S5-40 PAT318, Section 5, March 2005 STEP FILE n ISO STEP (Standard for the Exchange of Product Model Data) u Application Protocols (AP) l AP 203: geometry and configuration controlled design data l AP 214: represents all types of geometry, including pipe and harness data, and components l AP 209: finite element model, including composites, and results

41 S5-41 PAT318, Section 5, March 2005 n AP203 / 214, STEP Options include u Import to Parasolid: Yes l Imported geometry will be parasolid type geometry l Trimmed Surface Type n Select simple (4 edges) or general trimmed l Group Classification n Displays dialog box for directing entities to MSC.Patran groups l Sew Sheet Bodies n PATRAN Sew: sew sheet bodies using MSC.Patran software n Verify Boundary: similar to Geometry: Verify/Surface/Boundary l Equivalence Edge Vertices n Equivalence vertices during import l Save Transmit File n Save parasolid xmt transmit file created during import STEP FILE (Cont.) AP 203 / 214

42 S5-42 PAT318, Section 5, March 2005 STEP FILE (Cont.) AP 203 / 214 (Cont.) n AP203 / 214, STEP Options include u Import to Parasolid: No l Imported geometry will not be parasolid type geometry, but SGM geometry (MSC.Patran native Solid Geometry Model) l Entity Layers n All layers, or selected layers, are imported l Group Classification n Displays dialog box for directing entities to MSC.Patran groups

43 S5-43 PAT318, Section 5, March 2005 STEP FILE (Cont.) AP 209 n AP209, STEP Options include u Import to Parasolid: No l Imported geometry and finite element data will not be parasolid l Entity Layers n All layers, or selected layers, are imported l Group Classification n Displays dialog box for directing entities to MSC.Patran groups l Imported Data n Select the types of data to be imported

44 S5-44 PAT318, Section 5, March 2005 FILE EXPORT OPTIONS

45 S5-45 PAT318, Section 5, March 2005 FILE TYPES EXPORTED Parasolid xmt file Specific types of parasolid geometry Curves Surfaces Solids Can specify the parasolid version

46 S5-46 PAT318, Section 5, March 2005 FILE TYPES EXPORTED CATIA V4 Specific entity types Curves Surfaces Solids

47 S5-47 PAT318, Section 5, March 2005 FILE TYPES EXPORTED IGES Specific entity types Curves Surfaces Solids Nodes and elements Coordinate frames No results Select groups for export

48 S5-48 PAT318, Section 5, March 2005 FILE TYPES EXPORTED MSC.Patran 2.5 neutral file Specific entity types Nodes Elements Material properties Element properties No results Parametric cubic geometry only Select groups for export

49 S5-49 PAT318, Section 5, March 2005 FILE TYPES EXPORTED STEP Application Protocols (AP) AP 203 AP 209 AP 214 AP 203, 214 entities Curves Surfaces Solids AP 209 entities Limited geometry Mesh Analysis Results

50 S5-50 PAT318, Section 5, March 2005 MSC.PATRAN GEOMETRY APPLICATION

51 S5-51 PAT318, Section 5, March 2005 Geometry can be constructed in MSC.PATRAN by Editing imported CAD geometry (e.g. Edit/Surface/Sew) Building with respect to existing geometry (e.g. Create/Solid/Extrude) Creating copies of existing geometry (Transform) GEOMETRY CONSTRUCTION Extracting a curve Gliding a surface to create a solid Rotating Mirroring

52 S5-52 PAT318, Section 5, March 2005 GEOMETRY ENGINES IN MSC.PATRAN There are two approaches that can be used in MSC.Patran to create and edit geometry. They are standard and parasolid Standard tools Use MSC.Patran unique code / libraries Has a long history of use Parasolid tools Use parasolid libraries in MSC.Patran Need MSC.Patran parasolid tool license Pages with parasolid tool indicated mean that the approach described uses the parasolid libraries

53 S5-53 PAT318, Section 5, March 2005 ACCESSING GEOMETRY FORMS Create or edit geometry under the Geometry icon in the MSC.Patran main menu.

54 S5-54 PAT318, Section 5, March 2005 GEOMETRY FORM ANATOMY The strategy behind working with the geometry form: Set an objective, such as creating a point Provide the details associated with creating the entity using the specified method... Action Object Method... Surface XYZ Face Revolve Curve XYZ Trimmed Revolve Point Manifold Chain Revolve XYZ Interpolate Extract Project CreateDelete PointCurveSurfaceSolid...

55 S5-55 PAT318, Section 5, March 2005 SELECT MENU MSC.Patran provides an entity selection filter When the cursor is placed in a list box it causes the filter selection menu to be displayed Select menu icons filter entity selection; the only entities selected are of type of chosen filter icon Selections available depend on what is being done, e.g. create a point using XYZ option allows screen picking of only the entities on the front of the model Pick only geometry point or finite element node Pick only geometry point Pick only finite element node

56 S5-56 PAT318, Section 5, March 2005 GEOMETRIC ENTITIES - POINT

57 S5-57 PAT318, Section 5, March 2005 CREATE / POINT / XYZ Create points at X, Y, Z location Locations where points are to be created may be specified by either: (X,Y,Z) coordinates (list of coordinates), e.g. [ ] [0 0 70] Picking a choice from the select menu and following the menu prompts, e.g. Node u 2 1 u 3

58 S5-58 PAT318, Section 5, March 2005 POINT CREATE Create Point 3 at the center of an arc Create a point at the intersection of a curve and a surface Create points non- uniformly on a curve x a 1 3 x Create a point at parametric location a x 1 x x x

59 S5-59 PAT318, Section 5, March 2005 SHOW / POINT / DISTANCE Provide distance between a point and other entity (i.e. point, surface).

60 S5-60 PAT318, Section 5, March 2005 GEOMETRY TRANSFORM* MethodComment TranslateTranslate entity through a specified vector RotateRotate entity about a defined axis through a given angle ScaleUse a multiplicative factor applied to individual coordinate MirrorCreate a mirror image of entity across a defined plane McoordTransform entity in one coordinate frame into another with same relative position PivotTransform entity within a plane defined by a pivot and two points PositionEntity transformed to a set of destination-position-points will maintain its relative position to a set of original-position-points VsumVector sum of the coordinate locations of two sets of existing entities to create a new entity MscaleExisting entity is simultaneously moved, scaled, rotated and/or warped to a new position using a rotation matrix * Transform operations for geometry types point, curve, surface and solid

61 S5-61 PAT318, Section 5, March 2005 GEOMETRIC ENTITIES - CURVE

62 S5-62 PAT318, Section 5, March 2005 Patran has the capability of creating various types of geometry, for example: Implicit form, i.e. conic, elliptical Explicit form, i.e. parametric cubic, Beizier, NURBS Patran uses Neutral File convention to indicate that cubic parametric geometry (parametric cubic geometry) will be created, e.g. with a similar equation for Y and Z Neutral File convention can be selected under Geometry Representation in Preferences/Geometry Some geometry is created using only Neutral File convention, e.g. Create/Curve/Point GEOMETRY TYPES

63 S5-63 PAT318, Section 5, March 2005 CURVE CONSTRUCTION Must use the select menu for picking the curve and point

64 S5-64 PAT318, Section 5, March 2005 CREATE / CURVE / MANIFOLD Manifold refers to creating new geometry on (coincident with) existing geometry, e.g. curve on surface from one point to another point Before After Surface

65 S5-65 PAT318, Section 5, March 2005 CREATE / CURVE / CHAIN Create a composite curve from two or more existing curves and/or edges It retains exactly all the information of the constituent curves Individual curves Chain curve used for trimmed surface Individual curvesChain (composite) curve X Y Z 11 X Y Z

66 S5-66 PAT318, Section 5, March 2005 AUTO CHAINING FEATURE Provide user with interactive, more controllable way to chain curves Chaining starts by selecting a starting curve Decisions on how to proceed with the chaining process are made through the toggles and buttons on the form, i.e. Next (find another possible path for chain), or OK (proceed along the current path) Accessible from Create/Curve/Chain or Create/Surface/Trimmed forms

67 S5-67 PAT318, Section 5, March 2005 EDIT / CURVE / BREAK Creates two curves by breaking an original curve or edge at a parametric position along the curve between 0.0 and 1.0 Trimmed surface 3 Point 21 is created at parametric 0.4 position along u (or c1) direction 3 3 Edge

68 S5-68 PAT318, Section 5, March 2005 CURVE EDIT Must use select menu for picking the curve and point Patran extracts points from all curves, then creates one spline curve from them The parametric coordinate for each curve is represented by a line with a 1 Original curve represented by set of parametric cubic curves (simple math. representation) complex mathematical representation Single curve;

69 S5-69 PAT318, Section 5, March 2005 CURVE SHOW Curve ID 1 Start Point 1 End Point 2 Length Type ParametricCubic First Curve ID 1 Secon Curve ID 2 Angle 45. Minimum Distance 0. Minimum Location1 [ ] Minimum Location2 1on> Curve ID 1 Start Point 1 End Point 2 Length Center [ ] Radius 1. Type Arc Curve ID 1 Start Point 1 End Point 2 Length 1.4 Type ParametricCubic ParametricCubic ParametricCubic

70 S5-70 PAT318, Section 5, March 2005 GEOMETRIC ENTITIES - SURFACE

71 S5-71 PAT318, Section 5, March 2005 PARAMETRIC SURFACE CREATE Curves must be non-intersecting (non-touching)Curves must be end-to-end Must use the select menu for picking both surface and point; fillet is parametric bicubic.

72 S5-72 PAT318, Section 5, March 2005 TRIMMED SURFACE CONSTRUCTION Three options for creating a trimmed surface in MSC.PATRAN Planar Trimmed 2-D Surface Surface Trimmed 3-D Surface Composite Trimmed

73 S5-73 PAT318, Section 5, March 2005 TRIMMED SURFACE CONSTRUCTION (Cont.) When creating a trimmed surface, one must define its edges Chain together curves to form closed loops One outer loop to define the outer boundary As many inner loops as necessary (if any) to define holes/cutouts Define curvature of surface Planar trimmed for a flat surface Surface trimmed requires a parent surface (must be parametric) to define the curvature of the new surface; only one surface permitted For composite trimmed creation must specify all surfaces to be combined

74 S5-74 PAT318, Section 5, March 2005 CREATE TRIMMED SURFACE EXAMPLE The Outer Loop List can have only one curve ID, e.g. Curve 5; the curve must close on itself There can be as many inner loops as needed, e.g. Curve 6, 7; only one curve per inner loop Single surface ID in Surface List, e.g. Surface 1. It is the parent surface and must be parametric (green) Curves and Parent SurfaceResulting Trimmed Surface Parent surface Outer loop

75 S5-75 PAT318, Section 5, March 2005 COMPOSITE SURFACE One composite surface created from a set surfaces Meshing will ignore the original interior vertices and edges Original Surfaces Composite Surface with Mesh

76 S5-76 PAT318, Section 5, March 2005 CREATE COMPOSITE SURFACE A composite surface is created from multiple surfaces Useful for coarse meshing a region of numerous surfaces Can use parametric composite surfaces to create parametric solids, which can be hex meshed User defined boundary features such as vertices, inner loops, and curves at perimeter gaps (Preview Boundary) Vertices Use All Edge Vertices – all vertices at outer perimeter of surfaces in Surface List Vertex List – if only use some vertices, e.g. create parametric surface Inner Loop Option – All, None, Select (some)

77 S5-77 PAT318, Section 5, March 2005 CREATE COMPOSITE SURFACE (Cont.) Preview Boundary Can use Preview Boundary to see if continuous boundary (white) exists around perimeter of surfaces; if not, can add (create) curves, or remove curves or edges from list on the fly to define desired outer perimeter Select menu can only be used to pick curves or edges, or 2 points to define a curve Curve or Edge

78 S5-78 PAT318, Section 5, March 2005 CREATE COMPOSITE SURFACE (Cont.) Options can be used to assist with surface creation Perimeter (boundary) gaps less than Cleanup Tol. will be closed Gap Distance is similar to Cleanup Tol., except it refers to gaps between internal edges of surfaces

79 S5-79 PAT318, Section 5, March 2005 EXAMPLE: COMPOSITE SURFACE Four Non-congruent Surfaces Trimmed Composite Surface Parametric Composite Surface Create composite surfaces Surface 1:4 Surface type Trimmed: use All Edge Vertices Simple: use four corner vertices Options Clean up Tol.=0.071 Gap Distance=0.071 Continued Preview Boundary Add (Two Points icon) Select point pairs at all 4 outside perimeter gaps Remove (Curve or Edge icon) Select all 8 interior edges

80 S5-80 PAT318, Section 5, March 2005 CREATE MIDSURFACE FROM SOLID Create surface midway through thickness of portions of a parasolid solid Use for shell meshing a solid Two modes for creation Automatic Specify the thickness of the regions for which surfaces are to be created Manual Two faces of a given solid between which a mid-surface is to be created must be specified Solid Face List – a face Offset Solid Face List – opposing face Manual Automatic

81 S5-81 PAT318, Section 5, March 2005 SURFACE EDIT Set of bicubic surfaces replaces original surface Complex mathematical representation Can use simultaneously with all surfaces Surfaces have continuous slope

82 S5-82 PAT318, Section 5, March 2005 SURFACE EDIT (Cont.) Point 35 Parametric Surface 6 Trimmed surface with hole Trimmed Surface 8 with hole Parametric surface without hole Trimmed Surface 4 Remove vertex Parametric surface Point 44 Parametric Surface 2 New vertex Trimmed surface

83 S5-83 PAT318, Section 5, March 2005 EDGE MATCH SURFACE Mesh continuity requires adjacent surfaces be congruent Two non-congruent surfaces may be matched along adjacent edges Congruency can also be enforced using Edit/Surface/Break Edit/Surface/Sew includes Edge Match and Edit/Point/Equivalence All surfaces have four edges Add vertex to surface 1 at point 5

84 S5-84 PAT318, Section 5, March 2005 SURFACE TRANSFORM MIRROR OPTION First, select the appropriate select menu icon – coordinate direction 1 Second, click on local Coordinate System 1 in the viewport to specify the mirror plane to be coincident with the local YZ-Plane Third, select the geometry to be mirrored

85 S5-85 PAT318, Section 5, March 2005 VERIFY SURFACE BOUNDARY Plots free and non-manifold surface edges in model Free edge: no congruent adjacent surface edge (magenta circle) Non-manifold edge: shared by more than two surface edges (blue dot) Free edge Non-manifold edge

86 S5-86 PAT318, Section 5, March 2005 GEOMETRIC ENTITIES - SOLID

87 S5-87 PAT318, Section 5, March 2005 SOLID CONSTRUCTION Use nonintersecting parametric surfaces to create parametric solid Use set of any type of surfaces to create an MSC.Patran native B-rep solid Use 5 parametric surfaces to create 6 faced parametric solid Glide a parametric surface along a curve to create a parametric solid

88 S5-88 PAT318, Section 5, March 2005 CREATE PARASOLID B-REP OR PARAMETRIC SOLID BY EXTRUDING SURFACE Extrude a surface (or solid face) to create a solid Select to create either a TetMeshable (Parasolid B-rep) or IsoMeshable (parametric) solid If select TetMeshable the surface can be parametric or trimmed If select IsoMeshable the surface must be parametric Parasolid tool IsoMeshable TetMeshable

89 S5-89 PAT318, Section 5, March 2005 CREATE PARASOLID B-REP OR PARAMETRIC SOLID BY REVOLVING SURFACE Revolve a surface (or solid face) to create a solid Similar to extrude – select either TetMeshable or IsoMeshable Same restrictions on surface types as for extrude Parasolid tool IsoMeshable TetMeshable

90 S5-90 PAT318, Section 5, March 2005 CREATE PRIMITIVE SOLIDS Create Parasolid B-rep solids of various basic shapes Shapes are Block, Cylinder, Cone, Sphere, and Torus Parasolid Solid can be created quickly using this form, or it can be created manually using Geometry/Create/ Solid/B-rep (get Patran native B-rep Solid), then refitting to create a parasolid B- rep solid Primitive solid can only be meshed with the TetMesher Parasolid tool

91 S5-91 PAT318, Section 5, March 2005 SOLID EDIT MethodComment BreakBreak a solid into multiple solids using a selected option such as a surface, parametric location, etc. BlendCreate a set of cubic parametric solids from a set of parametric solids such that the first derivative of shape is continuous across interfaces DisassembleDisassemble a B-rep solid into a set of surfaces (may be parametric or trimmed) RefitReplace an existing complex shaped parametric solid with a set of simple cubic parametric solids. The extent to which the new solids match the original solid depends on how many solids are created. Also, can create a parasolid solid. ReverseReverse the parametric directions associated with the solid BooleanAdd, subtract, or intersect parasolid solids. Parasolid tool Edge BlendCreate fillets or chamfers. Parasolid tool ImprintBreak parasolid faces at edges of other solids. Parasolid tool ShellRemove space from parasolid solid to create walls. Parasolid tool

92 S5-92 PAT318, Section 5, March 2005 EDIT SOLID BY REFIT Edit solid three ways Option To TriCubicNet causes a set of cubic parametric solids to be created to represent the original solid Refit parameters u Density, v Density, w Density* Option To TriParametric is similar to To TriCubicNet except a tolerance is used instead of u Density, etc. Option To Parasolid causes a parasolid solid to be created from the original solid Parasolid tool * Density is the number of solids that will be created in the u, v, w direction.

93 S5-93 PAT318, Section 5, March 2005 SOLID GEOMETRY BOOLEAN Solids to be combined can be Patran native B-rep, parasolid B-rep solid, and/or parametric Solids could have been created in Patran or imported Boolean operations are Add, Subtract, and Intersect Any combination of solid types results in creating a parasolid B-rep solid Parasolid tool Add B-rep Parametric B-rep (from Add) 1 2 3

94 S5-94 PAT318, Section 5, March 2005 GEOMETRIC ENTITIES – COORDINATE FRAME

95 S5-95 PAT318, Section 5, March 2005 DEFINING COORDINATE FRAMES The 3 axes, for each coordinate system, are generically referred to as the 1, 2, 3 axes with the above definitions Rectangular X Y Z Cylindrical R Z Spherical R Z X Y A B C P(X,Y,Z) Z Y X Z R A B C P(R,,Z) R Z R A B C P(R,, ) R

96 S5-96 PAT318, Section 5, March 2005 COORDINATE CREATE MethodComment 3PointCreate a coordinate frame by defining an origin, a point along the axis 3 and a point in the 1-3 plane AxisA point on axis i and another on axis j EulerThree consecutive rotations about user defined axes NormalSpecify an origin and a surface

97 S5-97 PAT318, Section 5, March 2005 CREATE COORDINATE ALIGNED WITH SURFACE NORMAL Creates a rectangular coordinate system Origin at a point on a surface or solid face Coordinate frame axis 3 aligned normal to the surface or face Coordinate frame axis 1 aligned with either parametric direction

98 S5-98 PAT318, Section 5, March 2005

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