CATIA破面修复教程

1、Copyright DASSAULT SYSTEMES 2002,1,Healing Assistant,CATIA Training Foils,Version 5 Release 9June 2002 EDU-CAT-E-HA1-FF-V5R9,Copyright DASSAULT SYSTEMES 2002,2,Course Presentation,Objectives of the course In this course you will learn why, when and how to use the application HA1 Healing Assistant Ta

2、rgeted audience All designers, especially tooling designers Prerequisites Wireframe do it by creating a new Join rather than by modifying the first one, in order to avoid suppressing small edge curves Do not increase the value too much, if needed use Healing Assistant to find the invalid topological

3、 situations (surface connection checker) to close the remaining free sides (Local Join, Local Healing),How to Choose a Merging Distance (2/2),Copyright DASSAULT SYSTEMES 2002,11,Workbench Presentation,In this lesson, you will learn about: The Access to the Healing Assistant Workbench The User Interf

4、ace The Methodology for Healing,Copyright DASSAULT SYSTEMES 2002,12,Accessing the Workbench,1- Start,At any time, the current workbench is indicated by an icon on the right hand side of the screen.,2- Mechanical Design,3- Healing Assistant,Copyright DASSAULT SYSTEMES 2002,13,The User Interface,5 act

5、ions are specific to Healing Assistant, the others are taken from other workbenches,Copyright DASSAULT SYSTEMES 2002,14,Methodology for Healing with the Healing Assistant,Prepare data = put all surfaces to join in an open body, remove unnecessary data,Join all surfaces with a strict tolerance (for e

6、xample 0.01mm),Check all surfaces individually,Optional: measure the gaps between surfaces to evaluate the tolerance of the imported data,Optional: clean all surface boundaries at once to simplify the model,Check for bad topology situations,Repair invalid surfaces,Repair bad topology situations,Anal

7、yze free sides,Close free sides,Create solid,If invalid surfaces,If bad topology,If OK,Copyright DASSAULT SYSTEMES 2002,15,Model Analysis with the Healing Assistant,In this lesson you will learn about: Checking Surfaces Individually Checking for Invalid Topological Situations,Copyright DASSAULT SYST

8、EMES 2002,16,Face Checker,The purpose of the face checker is: To check each surface and find out if it is valid for a given merging distance To sort the surfaces by moving the invalid ones to a new open body,The selection of surfaces to check is the same as for the Join operator,The Sort option can

9、be used when there are multi-cell (multi-face) surfaces among the selected surfaces Move: invalid surfaces are moved to a new open body Split and Move: only invalid faces are moved to a new open body, their complement remains in the original body None: no surface is transferred to a new body,Merging

10、 distance used for the validity checked: the detected surfaces could not be included to a Join with this value of the merging distance,Internal check: if some selected surfaces are multi-cell, you can choose to activate an individual check of each face rather than only a global check of the whole su

11、rface,Angular threshold : not used in R9,WARNING: checking all surfaces with Face Checker and removing the surfaces detected invalid does not ensure that the Join operator will succeed. New invalidities may appear during the Join process itself.,Copyright DASSAULT SYSTEMES 2002,17,Surface Connection

12、 Checker (1/2),You can check the connections between several surfaces or inside a multi-cell surface If only one surface is selected, the operator checks its internal continuities, if several surfaces are selected, only external connections are checked You can measure gaps (in mm), tangency disconti

13、nuities (in degrees) and even curvature discontinuities (in %), Discontinuities greater than a given value are highlighted on screen Use this function to find tangency gaps close to 180 degrees, they are possible causes for the “Bad Topology” message in Join For example, find gaps greater than 179 d

14、egrees,Gaps greater than 0.01mm,Sharp edges with angle greater than 179 degrees,Curvature discontinuities greater than 5 %,Copyright DASSAULT SYSTEMES 2002,18,Surface Connection Checker (2/2),Discontinuities are identified as gaps You can reframe on a gap to analyze it You can transfer gaps to a new

15、 open body for later analysis,Copyright DASSAULT SYSTEMES 2002,19,Exercise Presentation,And now practice on the first and second steps of the lateral fender exercise to learn about : Face checker Surface connection checker,Copyright DASSAULT SYSTEMES 2002,20,Creating Topology,In this lesson, you wil

16、l learn about: Repairing the Invalid Surfaces Repairing the Bad Topology Situations Checking for Free Sides,Copyright DASSAULT SYSTEMES 2002,21,Repairing Invalid Surfaces,Main cases of invalid surfaces are described page 7 You can repair invalid elements by one of these methods Recreate by Split usi

17、ng the boundary and support surface of the invalid surface In particular cases, it may be quicker to discard the invalid surface and to create a new one using the standard surface creation tools of CATIA,General case: recreate the surface by SPLIT Isolate the invalid element Create its full BOUNDARY

18、 (as a datum) If necessary: SMOOTH CURVE to the boundary DISASSEMBLE the boundary, check and repair the curves and JOIN them back UNTRIM the surface SPLIT the surface back.,Simple situations: replace the surface by a new element FILL LOFT or BLEND (specially for ruled surfaces) ,Repairing the invali

19、d elements is usually very easy and quick once they have been located,Copyright DASSAULT SYSTEMES 2002,22,Face Smooth,Invalid surfaces can also be repaired by the Face Smooth command (mono-face surfaces only) It modifies the edges of the boundaries within a tolerance in order to: Fill gaps between e

20、dges up to a given length Correct small tangency breaks up to a given angle Correct curvature discontinuities up to a given % value It can also Suppress very small edges by removing them or concatenating them Reduce the number of curves by concatenating edges which are continuous in tangency,Copyrig

21、ht DASSAULT SYSTEMES 2002,23,Repairing Bad Topology Situations,Surfaces identified as possible causes for bad topology situations have to be sorted out using the connection checker These surfaces must be carefully analyzed to find out if they cause a problem or not They may simply be adjacent surfac

22、es with opposite orientations Bad topology situations can usually be repaired by: Deleting unnecessary surfaces Trimming surfaces Correcting surfaces which cause an inconsistency in orientation Repairing bad topology situations is easy once they have been precisely located on the model,Copyright DAS

23、SAULT SYSTEMES 2002,24,Checking for Free Sides (1/2),You can display the free sides of a surface With the Boundary function to highlight the free sides The Boundary function gives an explicit message when the surface is closed With the Tools/Options/Display/Visualization menu,Copyright DASSAULT SYST

24、EMES 2002,25,Checking for Free Sides (2/2),There are only 4 possible cases of free sides,2: Duplicated element (one copy of the element is integrated to the topology as a non connex domain),1: Gap (including overlap) greater than Join merging distance,4: Missing element,3: Invalid element (not detec

25、ted by the Join operator),Copyright DASSAULT SYSTEMES 2002,26,Exercise Presentation,And now practice on the third step of the lateral fender exercise to learn about : Repairing invalid surfaces Repairing bad topology situations Checking for free sides,Copyright DASSAULT SYSTEMES 2002,27,Closing a To

26、pology,In this lesson, you will learn about: Fixing Unwanted Free Sides of a Topological Surface Fixing Gaps at the Topology Level Fixing Gaps both at the Topology and Geometry Levels,Copyright DASSAULT SYSTEMES 2002,28,Fixing Free Sides (1/3),Once you have created a topology you have to make it clo

27、sed (watertight, seamless) A surface is closed if it can be used to create a solid For that you need to analyze and suppress all free sides,solid created by Close Surface,solid created by Split or Pad/Up to surface,Example: molded part,Example: die face,Copyright DASSAULT SYSTEMES 2002,29,Fixing Fre

28、e Sides (2/3),Missing elements, duplications and invalid elements are easy to correct once they are located,Duplicated element: just remove the unnecessary element from the topology and delete itAs unnecessary copies of duplicated elements are included to the Join as non connex domain, you can also

29、use the Near operator to eliminate the unwanted non connex domains,Missing element: you can create missing elements by Fill or any other surface creation tool,Invalid element: remove the invalid element from the topology and recreate it with Fill or any other surface creation tool,Copyright DASSAULT

30、 SYSTEMES 2002,30,Fixing Free Sides (3/3),Once missing elements, duplications and invalid elements are corrected, only gaps remain You can measure gaps with the Surface connection Checker Gaps can be corrected: Only at the topological level by increasing the join merging distance with Join or with L

31、ocal JoinGaps still exist on the geometry, they are only hidden At both topological and geometrical levels: by removing the face which is badly connected to the others and replacing it by a new one by Healing or Local Healing,To remove a face from a topology, you must use Extract with the Complement

32、ary mode option. The result is a new surface including all faces except the selected one.,Selected face,Copyright DASSAULT SYSTEMES 2002,31,Local Join,Local Join can be used to close a given gap without changing anything to the rest of the surface The concept is to release the tolerance locally, onl

33、y for the selected edges You can also select a Boundary to process all gaps in one shot You can close the gap on the topological level only or both on the topological and geometrical levels,Choose a simple Join (topological level) or a Join + Healing (topological and geometrical levels),List of sele

34、cted edges (all of them must belong to the same surface) or Boundary curve,Not available in R9,New tolerance to be applied to selected edges,Copyright DASSAULT SYSTEMES 2002,32,The Healing Operator,The concept of Healing is to measure connections between faces (same as Join) and to modify the faces

35、when the distance is not within a given tolerance (merging distance) The distance is reduced to the user specified Distance Objective Healing = Join + modification of surfaces to close geometry at shared edges,d HEALING modifies the surfaces to close the geometry d merging distance : the geometry is not closed but HEALING does not modify anything because the topology is also not closed,The process is totally automatic: the whole surface is processed HEALING fi