CATIA,简易教学,快速入门 1-草图设计

草图设计SketcherVersion5Release8

January2002EDU-CAT-E-SKE-FF-V5R8CATIA培训教程CATIATraining

Foils1CopyrightDASSAULTSYSTEMES2002课程介绍CoursePresentation学习本课程的目的Objectivesofthecourse学习如何进行草图设计、如何施加约束、及如何编辑2D轮廓。这些轮廓被用来生成实体（solid）和曲面（surface）。Inthiscourseyouwilllearnhowtosketch,constrain,andedit2Dprofiles.Theseprofilesarethenusedtogeneratesolidsandsurfaces培训对象：初学者TargetedaudienceNewusers

预备知识：CATIA基础教程Prerequisites

CourseCATIABasics1day2CopyrightDASSAULTSYSTEMES2002目录TableofContentsCATIA草图设计介绍IntroductiontoCATIASketcher p.4生成简单的轮廓SketchingSimpleProfiles p.13生成预定义轮廓SketchingPre-DefinedProfiles p.52编辑轮廓EditingProfiles p.58对轮廓的操作OperationsOnProfiles p.68施加约束SettingConstraints p.102草图的管理ManagingSketches p.1263CopyrightDASSAULTSYSTEMES2002CATIA草图设计介绍

IntroductiontotheCATIASketcher这部分学习CATIAV5草图设计用户界面和基本功能。InthislessonyouwillseetheV5CATIASketcheruserinterfaceandbasicfunctions4CopyrightDASSAULTSYSTEMES2002草图设计器是一套帮助用户快速生成2D几何元素的工具。TheSketcherisasetoftoolstohelptheuserquicklygenerate2DGeometry.设计完成的草图用来生成实体（Solid）和曲面（Surface）。ThecompletedSketchcanthenbeusedtogenerateSolidsandSurfaces在草图设计器中，元素间定义的约束允许快速修改草图，因此草图设计器是建立实体（Solid）和曲面（Surface）的基础。ThecapabilitytodefineConstraintsbetweenelementsintheSketcherallowsforquickmodificationoftheSketchandconsequentlytheSolidsorSurfacesthatarebasedonit.其它一些工具，例如启发式约束可以让用户找到更多的设计途经。OthertoolssuchasAnimateConstraintsenabletheusertoexploredesignalternatives为什麽使用草图设计

WhyUsingtheSketcher?5CopyrightDASSAULTSYSTEMES2002你可以在任何一个工作台中选择草图器（Workbench）工具进入草图器YoucanalsoaccesstheSketcherbyselectingtheSketchericonfromanyWorkbenchwhereitispossibletodoasketch进入草图设计工作台的方法：Start>MechanicalDesign>Sketcher然后选择一个plane或者在一个对象上选择一个face。Start>MechanicalDesign>Sketcherthenselectaplaneorafaceonanobject草图设计工作平台SketcherWorkbench6CopyrightDASSAULTSYSTEMES2002草图设计工具SketcherDesigntools...退出到3D空间Exitto3DSpace零件树Parttree标准工具条Standardtools新的草图NewSketch当进入到草图设计工作平台时，在零件树上就生成了一个新的草图标识（Sketch）ANewSketchwillregisterinthePartTreewhenenteringtheSketcherWorkbench约束工具ConstraintsIcons工具＆操作Tools&Operations草图设计界面（¼）：草图设计工作台概述

SketcherInterface(1/4):SketcherWorkbenchgeneral提示行7CopyrightDASSAULTSYSTEMES2002退出草图ExitSketcher轮廓草图Profile矩形，键孔，多边形...圆，椭圆，圆弧Circles,Ellipse,Arcs...样条曲线Spline椭圆Ellipse线Line轴Axis点Points...倒圆Corner导角Chamfer修剪Trimoptions...对称Symmetry投影Projection约束对话框Constraintsdialogbox约束Constraint自动约束AutoConstraint驱动约束AnimateConstraint轮廓Profiles

操作Operations约束Constraints草图设计界面（2/4）草图设计工具

SketcherInterface(2/4):SketcherTools8CopyrightDASSAULTSYSTEMES2002插入菜单或工具条Insertmenuortoolbars草图设计图标SketcherIcons预定义轮廓PredefinedProfiles圆Circles二次曲线Conic线Line点Point草图设计界面（3/4）工具条

SketcherInterface(3/4):Toolbars9CopyrightDASSAULTSYSTEMES2002一旦选择了用于草图设计的支持平面,则此平面平行于屏幕显示（确认激活以下设置Tools+Option+mechanicalDesign+Sketcher+Positionsketchplaneparalleltoscreen）Onceontheplaneonwhichyouwanttosketchhasbeenselected,itisdisplayedparalleltothescreen(ifTools+Option+mechanicalDesign+Sketcher+Positionsketchplaneparalleltoscreenisactive)可以使用鼠标进行缩放,平移和旋转.Itispossibletodozoompanningandrotation(usingthemouse).复位已经旋转的草图平面,选择正视图(NormalView)

即可。Toresetasketchplanerotation,selecttheNormalViewicon如果草图平面已经平行于屏幕显示,选择正视图工具即可显示背面.

IfyouselecttheNormalViewiconwhenthesketchplaneisalreadydisplayedparalleltothescreen,youwillturnthesketchplaneandseeitsotherside.草图设计界面（4/4）草图设计的支持平面

SketcherInterface(4/4):SketcherPlane10CopyrightDASSAULTSYSTEMES2002

草图是一个平面内一组2D元素的集合，一个平面可以支持几个草图。TheSketchistheholdingpointforagroup2Delementsonaspecificplane.TherecanbemorethanoneSketchusingthesameplaneassupport.V-H轴是草图的坐标原点0，0。TheV-HAxisisthe0,0fortheSketch.草图一般包括：轮廓（Profile），约束（Constraints）和尺寸（Dimensions）（尺寸也是约束的一种）。SketchesgenerallyconsistofaProfile,Constraints,andDimensions(atypeofConstraint).轮廓Profile约束Constraints尺寸Dimensions术语Terminology11CopyrightDASSAULTSYSTEMES2002进入到草图设计工作平台。AccesstheSketcherWorkbench生成几何元素CreateGeometricElements使用草图生成实体或曲面。UsetheSketchtoCreateaSolidorSurface约束几何元素ConstraintheGeometricElements选择一个平面、一个实体的face或者一个平面surface作为草图设计平面。Selectaplane,aSolidFace,oraPlanarSurfacetoSketchon当前工作的草图被加入到结构树中。AnIn-WorkSketchisaddedtotheSpecificationsTrees123456一般过程GeneralProcess12CopyrightDASSAULTSYSTEMES2002绘制简单草图SketchingSimpleProfiles学习如何常见的几何元素,以及如何使用草图工作平台中的各种工具。InthislessonyouwilllearnhowtocreatemostoftheSketchergeometricelements.YouwillalsolearnhowtousethevariousworkmodesavailablefortheSketcherWorkbench.

草图设计的辅助工具TheSketcherWorkModes轮廓线

Profile点

Points线

Lines样条曲线

Spline圆和圆弧

CirclesandArcs二次曲线

Conics轴

Axis小节RecapExercise13CopyrightDASSAULTSYSTEMES2002网格/捕捉Grid/Snap标准/构造几何元素Standard/ConstructionGeometry自动约束AutomaticConstraints自动尺寸标注AutomaticDimensions断面视图SectionView数值区ValueFieldsYouwilllearntheSketcherWorkModesbyusing

草图设计辅助工具TheCATIASketcherWorkModes14CopyrightDASSAULTSYSTEMES2002为什麽设置工作模式WhySketcherWorkModes?草图工作模式是绘制草图辅助工具。TheSketcherWorkModesaidyouwhileyousketchthegeometry.这些模式便于数值的输入，便于几何约束和尺寸约束的自动生成，也便于对3D几何元素的显示等。Theyfacilitateinputofvalues,automateGeometrical/DimensionalConstraintscreation,helpvisualize3Dgeometryetc...15CopyrightDASSAULTSYSTEMES2002修改网格点参数，选择菜单栏Tools+Options…然后再从对话框中选择MechanicalDesign选项，再选择Sketcher标签。Tomodifythegridparameters,selectTools+Options…fromthetopofthescreen,selectMechanicalDesignfromthedialogboxthen,selecttheSketchertab.

当生成线（轮廓，线段，圆，圆弧，曲线，……）时，在任何时候都可以激活或不激活捕捉网格点（snaptopoint）

图标。Whencreatinganylines(profile,segment,circle,arc,curve,…),youcanactivateordeactivatethesnaptopointiconatanytime.

当snaptopoint图标激活时，光标只捕捉网格点(graphicalcreation).但是此时如果输入坐标值，系统不考虑网格点，而是按照输入的坐标值定位点。Whenthesnaptopointiconisactive,thecursoronlysnapsonthepointsofthegrid(graphicalcreation).Ifyouentercoordinateswhenthesnaptopointiconisactive,thesystemdoesnottakeintoaccountthegridandplacethepointinaccordancewiththecoordinatesyouhaveentered.12345使用网格/捕捉UsingGrid/Snap16CopyrightDASSAULTSYSTEMES2002标准+构造几何元素Standard+ConstructionElements标准/构造几何元素Standard/ConstructionGeometry有两种几何元素：标准几何元素和构造几何元素。Twotypesofelements:StandardorConstruction标准几何元素代表大多数通常情况下建立的几何元素。Standardelementsrepresentthemostcommonlycreatedelements构造几何元素是为了便于绘制草图的辅助元素。Constructionelementsaimathelpingyouinsketchingtherequiredprofile.Theyfacilitateyourdesign建立标准几何元素和构造几何元素的方法相同。Creatingstandardorconstructionelementsisbaseduponthesamemethodology.点击图标可以在两个模式之间切换。Clickingtheiconswitchesfromonemodetotheother17CopyrightDASSAULTSYSTEMES2002对于轮廓的第一个点，可以输入水平和垂直坐标，按tab键可以在水平或垂直坐标输入区输入坐标值。Fortheprofilefirstpoint,youcandefinetheHorizontalandVerticalcoordinates.BypressingthetabkeyyouaccesstheHorizontalcoordinatefield,soyoucanenterit.Bypressingthetabkeyoncemore,youaccesstotheVerticalcoordinatefield,soyoucanenterit在草图设计中，可以在此工具条中键入精确的坐标值、长度值或角度值。Duringsketching,youcanenterexactcoordinates/lengths/anglesintheToolsbar.对于轮廓的第二个点，也可以用tab键输入坐标输值，还可以通过键入第一点和第二点之间的距离和/或键入这条线段与水平坐标轴之间的角度来定义第二个点。Fortheprofilesecondpoint,youcanalsousethetabkeytoenteracoordinate,butyoucanalsodefinethesecondpointoftheprofilebyenteringthelengthofthesegmentbetweenthefirstandthesecondpointand/orbyenteringtheanglebetweentheHorizontalaxisandthesegmenttobecreated.当生成圆弧时，在工具条中可以键入圆弧的端点的水平和垂直坐标值，也可以键入半径值，可以通过按tab键在各个输入区之间切换。Whenprofilinganarc,thetoolsbarallowsyoutoentertheH

andVcoordinatesofthelastpointofthearcbutyoucanalsoenteraradius.Youcanenterthesecoordinatesbyusingthetabkey.如果确定了下面坐标中的一个(H,V,L,A或R)，则除了这个确定的数值外其他参数可随光标移动而改变。

Ifyouenteronlyoneofthecoordinates(H,V,L,AorR)youfixit,thismeansthattheotherparameterscanmovegraphicallybutnotthefixedone.

123数值区ValueFields以绘制轮廓线为例Forexample,inusingtheProfiletool...18CopyrightDASSAULTSYSTEMES2002自动尺寸标注AutomaticDimensions尺寸约束激活时，以下尺寸标注自动建立。----倒圆尺寸----导角尺寸----在数值输入区键入的尺寸Whenactivated:-cornerdimensions-chamferdimensions-dimensionsenteredintothevaluefieldsareautomaticallycreatedduringgeometryconstruction.选择尺寸约束（DimensionalConstraints）工具Insketcher,selecttheDimensionalConstraintsIcon多选矩形的两个边。Multi-selecttwoedgesofexistingrectangle2选择倒圆（Corner）工具SelectCornericon移动倒圆到要求的位置单击鼠标确定。Movethecornerpreviewtodesiredlocationandclick4激活尺寸约束（DimensionalConstraints）WithDimensionalConstraintson不激活尺寸约束（DimensionalConstraints）WithDimensionalConstraintsoff1319CopyrightDASSAULTSYSTEMES2002自动约束AutomaticConstraints2几何约束（GeometricalConstraints）激活。

WithGeometricalConstraintsOn几何约束（GeometricalConstraints）不激活。

WithGeometricalConstraintsOff1在草图空间建立几何元素时，根据鼠标位置的不同，在新生成的几何元素和已存在的几何元素之间会产生不同的约束，当出现满足要求的约束时，点击鼠标保存约束（即新生成的几何元素）。Starttosketchthegeometry.VariationsofvalidConstraintswillbeproposeddependingonwheretheMouseiswithrespecttotheexistinggeometry.WhenyouseetheConstraintyourequire,clickontheMousetostoretheConstraint(andthenewgeometry).注意在几何约束GeometricalConstraints关闭时，相切约束也可建立。NoticethatTangencyConstraintsarecreatedevenwhenGeometricalConstraintsisOff在Tools/Options/MechanicalDesign/Sketcher/Constraint/SmartPick

中指定你想搜索的约束。InTools/Options/MechanicalDesign/Sketcher/Constraint/SmartPickspecifywhichConstraintsyouwantdetected在草图设计中，选择几何约束图标（GeometricalConstraints）。Insketcher,selecttheGeometricalConstraintsIcon320CopyrightDASSAULTSYSTEMES2002截面视图SectionView选择工具条中切开草图平面CuttingPlane工具，可显示零件的截面视图，CutByPlaneInordertoseeaSectionViewofthepartwhilesketching,clickontheCuttingPlanecommandintheCutByPlaneToolbar.这只是个观察工具，在实体和剖切平面之间没有交线生成。Thisispurelyavisualizationtool,nointersectioncurvesarecreatedfromtheintersectionoftheSolidwiththeCuttingPlane.如果想在实体外形间建立约束（或者标注尺寸），可使用3D元素求交（Intersect3DElements）工具。IfyouneedtoConstrainto(orDimensionofffrom)theintersectedoutlineoftheSolid,usetheIntersect3DElementsTool21CopyrightDASSAULTSYSTEMES2002这部分学习如何生成轮廓线元素。YouwilllearnhowtocreateaProfileelement草图中的轮廓线ProfileintheSketcher3D空间看到的轮廓线Profileseenin3D轮廓线Profiles22CopyrightDASSAULTSYSTEMES2002

轮廓可以是：Aprofilecanbe:“封闭轮廓”（首尾元素相连）"Closed"(thelastelementconnectsupwiththefirstelementintheseries)

“开放轮廓”（首尾元素不相连）"Open"(thefirstandlastelementsintheseriesarenotincontact).

如果轮廓是封闭的，那么在轮廓的内部还可以包含其他轮廓Ifaprofileis"Closed",itcanhaveotherprofilescontainedinsideitsboundaries

轮廓线内还有轮廓线时，从外向内的布尔运算是加减交替进行的。Aprofile,withinaprofile,isshownheretoillustratehow"InnerDomains"work.Noticethereversalsofthebooleanoperationsbetweenadditionandsubtractionasweprogressfromtheoutsideinwards开放轮廓线Openprofile什么是轮廓线WhatareProfiles?

封闭或开放轮廓Closedoropen?轮廓线是一系列相互连接的平面几何元素，例如点，线，曲线。Aprofileisaseriesofadjacentplanargeometricelementssuchaspoints,lines,andcurves轮廓线常用于拉伸出基本草图特征（Sketch-Based）。ProfilesareusedtoextrudeSketch-BasedFeatures内部轮廓Innerprofiles

内部轮廓Innerprofiles23CopyrightDASSAULTSYSTEMES2002选择轮廓线profile工具InSketcher,SelectProfileicon选择线line工具（默认），然后点击两点生成线。Selectthelineicon(default)andclickontwopointstocreateline2选择相切圆弧tangentarc工具，再选择结束点。Selectthetangentarcicon,selectendpoint3水平约束Horizontalconstraint相切约束Tangencyconstraint选择线line工具，垂直拖拽生成线再点击鼠标。Selectthelineiconanddragverticallytocreatelineandclick5选择三点圆弧ThreePointArc工具，并选择两点画弧SelecttheThreePointArciconandclickontwopointstocreatearc4水平拖拽并点击鼠标生成线，在生成最后一个圆弧时，在圆弧的起点处先点击，再拖拽，再释放，这样CATIA自动进入到相切圆弧模式（tangentarc），而不是使用相切圆弧图标生成圆弧的。Draghorizontallyandclicktocreateline.RatherthanusingtheTangentarcicontocreatethefinalarc,click,dragandreleaseatthebeginningofthearcandCATIAgoesintothetangentarcmodeautomatically.61建立轮廓线CreatingProfiles24CopyrightDASSAULTSYSTEMES2002学习建立点的不同方法。Youwilllearnthevariousmethodstocreatepoints点Points25CopyrightDASSAULTSYSTEMES2002草图中生成点的方法

HowarePointsCreatedintheSketcher?草图中有两种方式生成点：PointscanbecreatedintheSketcherintwoways: -由用户生成Bytheuser -由系统生成Bythesystem当用户生成线时，系统会自动生成线的端点。当用户生成圆时，中心点被自动生成。Whentheusercreatesaline,theline’sendpointsareautomaticallycreatedbythesystem.Whentheusercreatesacircle,thecenterpointiscreated.这些自动生成的点可以被修改，方法是双击再键入新的数值。Thecoordinatesoftheseautomaticallycreatedpointscanlaterbemodifiedbydouble-clickingandenteringnewvalues.作为选择，用户可以首先直接生成点，然后再通过选择这些点来生成线或其他的几何元素。Alternatively,theusercanfirstcreatethepointsdirectly.Hecanthencreatealineoranyothergeometrybyselectingthesepoints.26CopyrightDASSAULTSYSTEMES2002在要生成点的位置点击鼠标。Clickthelocationwhereyouwantthepoint2在草图设计中，选择指定点（PointbyClicking）工具Insketcher,selectthePointbyClickingCoordinatesicon为了便于定位点，选择捕捉网格点（SnaptoPoint）工具，当要定位点的位置时，鼠标只捕捉网格点。Foreaseofplacingthepoints,selecttheSnaptoPointiconsothecursorwillsnaptothegridwhiletryingtolocatethepoint1指定点PointbyIdentification27CopyrightDASSAULTSYSTEMES2002填入直角坐标或极坐标。FillinthedesiredCartesianorPolarcoordinates2在草图设计中，选择由坐标生成点（PointbyusingCoordinates）工具

Insketcher,selectthePointbyclickingCoordinatesicon1如果激活尺寸约束模式（DimensionalConstraints），自动建立极坐标尺寸约束或直角尺寸约束。IftheDimensionalConstraintsmodeison,PolardimensionswillautomaticallybecreatedinthecaseofPolarinput.(CartesiandimensionscreatedinthecaseofCartesianinput)由坐标生成点PointsbyCoordinates28CopyrightDASSAULTSYSTEMES2002学习生成线的不同方法。Youwilllearnthevariousmethodstocreatelines线Lines29CopyrightDASSAULTSYSTEMES2002在CATIAV5中线的定义WhatisaLineinCATIAV5?在CATIAV5中，一个线段在结构树中用三个结点描述，两个点和一个线。InCATIAV5,alinesegmentisdescribedintheSpecificationsTreebythreenodes-twopointnodes(Point.1andPoint.2)andonelinenode(Line.1).线由它的父对象----点来支持lineissupportedbyitsparents-thepoints.当点的位置修改时（或者通过双击键入新的坐标，或者通过拖拽的方法），线的位置也相应改变。Whenthepositionofapointismodified(eitherbydouble-clickingandenteringnewcoordinates;orbydragging),thepositionofthelinewillchangeaccordingly.30CopyrightDASSAULTSYSTEMES2002在草图设计中，选择线（line）工具Insketcher,selectLineicon点击线的起点Clickstartingpointoftheline...…然后点击线的端点。thenclicktheendpoint或者可以在工具条的数值输入区键入值。OR…youcantypethelinespecificationsinthevaluefieldsoftheToolspallet321两点线LinesBetweenTwoPoints31CopyrightDASSAULTSYSTEMES2002选择切线（Bi-TangentLine）工具Insketcher,selecttheBi-TangentLineicon1选择线要与之相切的两个元素。Selectthetwoelementsyouwantthelinetobetangentto...2公切线的生成TheBi-Tangentlineiscreated切线Bi-TangentLines32CopyrightDASSAULTSYSTEMES2002学习如何在草图中生成样条曲线。YouwilllearnhowtocreateaSplineintheSketcher样条曲线Splines33CopyrightDASSAULTSYSTEMES2002使用哪一种样条曲线----是草图样条曲线还是3D样条曲线？

WhichShouldIUse-SketcherSplineor3DSpline?因为3D样条工具即可以在线架曲面（WFS）或表面设计（GSD）中应用，还可以在2D方式下应用（生成的几何元素在一个平面内），那么到底什么时候用草图样条，什么时候3D样条又更适合呢？Sincethe3DSplineTool-availablewithintheWireframe&Surfaces(WFS)orGenerativeShapeDesign(GSD)Workbenches-canalsobeusedina2Dmanner(withGeometryonSupportbeingaplane),whenshouldyouusetheSketcherSplineandwhenisthe3DSplinemoreappropriate?通常情况下，草图样条用以建立实体的草图基础特征。（尽管pad和pocket也可以用3D样条曲线来生成）。Ingeneral,usetheSketcherSplinetocreateSketchesforgeneratingsolidSketch-BasedFeatures.(AlthoughPadsandPocketscanbegeneratedfrom3DSplines)当需要在样条曲线上施加更多的控制时，就要用到3D样条。例如：切失张力，曲率方向，曲率半径。Usethe3DSplinewhenyouneedmorecontrolovertheSpline-i.e.TangentTension,CurvatureDirection,CurvatureRadius.两种样条都可以生成Surface。SurfacescanbegeneratedfromSplinescreatedbyeithermethod.34CopyrightDASSAULTSYSTEMES2002点击一点作为样条曲线的起点。Clickfirstpointtostartthespline2双击确定样条曲线的结束点。Double-ClicktospecifythesplineEndPoint.4…然后点击样条曲线的第二点。thenclickthesecondpointofthespline选择样条曲线（spline）工具Insketcher,selecttheSplineIcon35…然后点击样条曲线的其它点。thenclickforthethirdpointofthespline4双击样条曲线的控制点，对控制点给定一个精确的坐标值，

或者在控制点上生成切矢，然后可以在这个矢量上应用约束，（例如让它平行于一条线）。Double-ClickonaSplineControlPointtospecifyexactcoordinatesortocreateaTangencyvectoratthatpoint.YoucanlaterapplyConstraintsonthisvector(i.e.makeitparalleltoaline).1双击样条曲线的控制点，对控制点给定一个精确的坐标值，或者在定义切矢之后再定义曲率半径。Double-ClickonaSplineControlPointtospecifyexactcoordinatesortodefineaCurvatureafteratangencyvector样条曲线的建立CreatingaSpline35CopyrightDASSAULTSYSTEMES2002选择第一条曲线Selectthefirstcurve2选择第二条曲线Selectthesecondcurve选择连接（connect）工具SelecttheConnecticon31结果如下：Youget:曲线的连接Connectingcurve36CopyrightDASSAULTSYSTEMES2002学习生成圆和圆弧的不同方法Youwilllearnthevariousmethodstocreatecirclesandarcs.圆和圆弧CirclesandArcs37CopyrightDASSAULTSYSTEMES2002CATIA中圆和圆弧的定义

WhatareCirclesandArcsinCATIA?CATIAV5中，一个圆包含两个结点。InCATIAV5,aCircleconsistsoftwonodes:Point.1

表示圆心的坐标Point.1specifyingthecoordinatesoftheCircleCenterCircle.1

表示圆半径Circle.1specifyingtheRadiusoftheCircle除此之外，圆弧还有两个结点。TheArcwillhavetwoadditionalnodes:Point.2表示第一个端点的坐标。Point.2specifyingthecoordinatesofonelimitPoint.3

表示第二个端点的坐标。Point.3specifyingthecoordinatesofthesecondlimit注意：当一个圆被修剪成只剩一部分时，此时结构树上也增加了两个点的描述。实际上它所继承的特性和圆弧是一样的。Note:WhenaCircleisTrimmedleavingonlyaportionofthecompletecircle.TwoadditionalpointsareaddedtotheSpecificationsTree.Infact,therepresentationbecomesthesameasthatofanArc.38CopyrightDASSAULTSYSTEMES2002点击一次定义圆心，然后拖拽鼠标。Clickoncetodefinethecenterpointofthecircle,thendragthecursor2…再点击一次定义圆的大小。andclickagaintodefinethecirclesize选择圆（cirle）工具。Inthesketcher,selecttheCircleicon13基本圆BasicCircles39CopyrightDASSAULTSYSTEMES2002选择三点圆（ThreePointCircle）工具Insketcher,selectThreePointCircleicon选择圆将经过三个点。Clickthreetimestodefine3points.Thecirclewillpassthroughthesepoints2413三点圆CirclesThroughThreePoints40CopyrightDASSAULTSYSTEMES2002选择用坐标圆（CircleusingCoordinates）工具Insketcher,selectCircleusingCoordinatesicon1键入圆心的绝对坐标Entertheabsolutecoordinatesofthecircle2键入半径Enterthesizeoftheradius3坐标圆CircleUsingCoordinates41CopyrightDASSAULTSYSTEMES2002点击第一个点作为圆弧的起点。Clickfirstpointtostartthearc...2然后点击圆弧的端点。Thenclicktheendpointofthearc4…再点击圆弧的第二个点。thenclickthesecondpointofthearc选择三点圆弧（ThreePointArc）工具Insketcher,selectThreePointArcicon31三点弧ThreePointsArcs42CopyrightDASSAULTSYSTEMES2002学习生成二次曲线的不同方法。Youwilllearnthevariousmethodstocreateconics二次曲线Conics43CopyrightDASSAULTSYSTEMES2002可以生成二次曲线的种类

WhichAretheConicsthatCanBeCreated?二次曲线Conic

输入要求RequiredInputs椭圆Ellipse 中心，长轴端点，曲线上的一点Center,MajorAxisLimit,PointonCurve抛物线Parabola 焦点，顶点，起点，端点Focus,Apex,StartPoint,EndPoint双曲线Hyperbola 焦点，中心点，顶点，起点，端点Focus,Center,Apex,StartPoint,EndPoint椭圆Ellipse抛物线Parabola双曲线Hyperbola44CopyrightDASSAULTSYSTEMES2002指定椭圆的中心。Clicktoindicatecenterpointofellipse2工具条中显示主轴端点的坐标。TheToolsToolbarthendisplaysvaluesfordefiningtheellipsemajoraxisendpoint…然后点击一点作为长轴的端点。thenclickthesecondpointforthemajoraxisendpoint选择椭圆（Ellipse）工具Insketcher,selectEllipseIcon3中心点坐标也可以在工具条中输入。CenterpointcoordinatescanalsobeinputintheToolsToolbar1生成椭圆CreatinganEllipse(1/2)45CopyrightDASSAULTSYSTEMES2002点击一点作为短轴的端点。Clicktoindicateforminoraxisendpoint4生成椭圆CreatinganEllipse(2/2)46CopyrightDASSAULTSYSTEMES2002指定抛物线的焦点。ClicktoindicatetheFocusPointoftheParabola2然后确定两个端点。Nextindicatethetwoendpoints…再点击一点作为顶点。thenclickthesecondpointfortheApex选择抛物线（Parabola）工具Insketcher,selecttheParabolaIcon3通常，工具栏随用户输入的步骤显示坐标值。Asalways,theToolsToolbariscontextualandallowstheusertoinputspecificpointcoordinatesduringthecreationsteps41生成抛物线CreatingaParabola47CopyrightDASSAULTSYSTEMES2002确定双曲线的焦点。ClicktoindicatetheFocusPointoftheHyperbola2然后给定两个端点。Nextindicatethetwoendpoints…点击第二点作为中心点。thenclickthesecondpointfortheCenter选择双曲线（Hyperbola）工具Insketcher,selecttheHyperbolaIcon3通常，工具栏随用户输入的步骤显示坐标值。Asalways,theToolsToolbariscontextualandallowstheusertoinputspecificpointcoordinatesduringthecreationsteps5…点击第三点作为顶点。clickthethirdpointfortheApex41生成双曲线CreatingaHyperbola48CopyrightDASSAULTSYSTEMES2002学习生成轴线的方法。YouwilllearnthemethodtocreateanAxisinSketcher轴线Axis49CopyrightDASSAULTSYSTEMES2002轴线的用途WhatistheAxisUsedfor?在建立旋转体（Shaft或

Groove）实体特征时，草图中必须包含轴线。用来围绕轴线旋转的轮廓线必须是封闭的或者其端点和轴线重合。

AnAxiselementmustbeincludedinaSketchfromwhichaShaftorGroovesolidfeatureiscreated.TheProfiletobesweptaroundthisaxismusteitherbeClosedorhaveitsendpointsCoincidenttotheaxis.草图轴线也可作为旋转曲面的旋转轴线（但不是必须的）。一条独立的直线或者实体的棱边也可以用来作为旋转轴线。这种情况下，该草图不必是封闭的或其端点与旋转轴线重合。AnAxisdrawnintoaSketchcanalsobeused(butnotrequired)togenerateaSurfaceofRevolution.AseparateLineorSolidEdgecanalsoservetospecifytheaxisofrevolution.Also,theProfileneednotbeClosednorCoincidenttotheaxisinthiscase.50CopyrightDASSAULTSYSTEMES2002轴线不能转换成构造元素。Axescannotbeconvertedintoconstructionelements选择轴线（Axis）工具Insketcher,selectAxisicon确定轴线的起点。Clickthefirstlocationforstartingpointoftheaxis...2…然后确定端点。thenclicktheendlocation轴线可随时用于镜向命令或者生成旋转体（grove或shaft）。Youwillneedaxeswheneverusingasymmetrycommandorcreatingagroveorshaft.使用上面的草图应用shaft命令，CATIA将使用上面定义的轴线生成旋转体。Usingtheshaftcommandonourprofilesketch,CATIAproducesashaftusingtheaxiswedefined31生成轴线CreatinganAxis51CopyrightDASSAULTSYSTEMES2002预定义轮廓草图

SketchingPre-DefinedProfiles这部分学习如何生成预定义轮廓。InthislessonyouwilllearnhowtoSketchthePre-DefinedProfiles预定义轮廓草图SketchingPre-DefinedProfiles小节RecapExercise52CopyrightDASSAULTSYSTEMES2002学习生成预定义轮廓草图的不同方法Youwilllearnthedifferentwaystocreatepre-definedprofiles矩形Rectangle有方向的矩形OrientedRectangle长圆孔ElongatedHole柱形长圆孔CylindricalElongatedHole锁孔KeyholeProfile平行四边形Parallelogram六边形Hexagon生成预定义轮廓草图

SketchingPre-DefinedProfiles53CopyrightDASSAULTSYSTEMES2002预定义轮廓是CATIA提供的工具，它便于生成标准的复杂的形状，只需最少量的输入就可完全描述图形的形状。Pre-DefinedProfilesaretoolstofacilitatethecreationofstandardcomplexshapeswiththeminimalnumberofinputsthatcanfullydescribeallaspectsofthatshape.预定义轮廓减少了鼠标键盘的交互性操作，从而加快了设计速度。ItincreasesproductivitybyreducingMouse/Keyboardinteractions预定义轮廓的介绍

WhatarePre-DefinedProfiles?54CopyrightDASSAULTSYSTEMES2002在生成所有的预定义轮廓时，阅读屏幕左下角的提示总是很有用处的。IncreatingallthePre-DefinedProfiles,itisalwaysusefultoreadthepromptsatthebottomleftcornerofthescreen或者在工具条的数值区键入矩形的描述。OR…youcantypetherectanglespecificationsinthevaluefieldsoftheToolspallet3选择矩形（Rectangle）工具Insketcher,selectRectangleicon确定矩形的起始角点。Clickthestartingcorneroftherectangle...2…然后再点击对角点。thenclickthediagonalcorner1矩形Rectangles55CopyrightDASSAULTSYSTEMES2002或者在工具条的数值区域键入平行四边形的描述。OR…youcantypetheParallelogramspecificationsinthevaluefieldsoftheToolspallet3选择平行四边形（Parallelogram）工具Insketcher,selectParallelogramicon1点击平行四边形起始角点。ClickthestartingcorneroftheParallelogram...2…然后点击第二个角点。thenclickforthesecondcorner…最后点击一点确定平行四边形的宽度和内角。finally,clicktodeterminethewidthandinternalanglesoftheParallelogram4平行四边形Parallelogram56CopyrightDASSAULTSYSTEMES2002或者在工具条的数值区域键入孔的描述。OR…youcantypetheholespecificationsinthevaluefieldsoftheToolspallet3选择长圆孔（ElongatedHole）工具Insketcher,selecttheElongatedHoleicon1指定孔的第一个中心。Indicatethefirstcenterofthehole...2…指定第二个中心。indicatethesecondcenter...…最后，点击确定长圆孔的半径。finally,clicktodeterminetheradiusoftheElongatedHole4长孔ElongatedHole57CopyrightDASSAULTSYSTEMES2002编辑轮廓EditingProfiles这部分学习编辑草图元素的工具。InthislessonwilllearntoolstohelpyoueditSketcherelements修改轮廓的几何元素ModifyingProfileGeometry小节RecapExercise58CopyrightDASSAULTSYSTEMES2002学习如何修改2D草图元素从而相应改变3D零件。Youwilllearnhowmodify2Dsketchelementstopropagatechangesto3Dparts修改轮廓的几何元素ModifyingProfileGeometry修改后AfterChange修改前Before59CopyrightDASSAULTSYSTEMES2002基本草图的特征依赖于构成其的轮廓形状。Sketch-basedfeaturesrelyonprofilesfortheirshape尤其是如果按照零件（part）的设计意图定义了约束，可以通过修改轮廓几何特性非常容易的达到设计改变的目的。

Especiallyifdefinedwiththeproperconstraintsthatrepresentthedesignintentofthepart,theprofilegeometrycaneasilybechangedfordownstreamdesignchanges修改后的体Modifiedcube修改轮廓几何元素的原因

WhyModifyProfileGeometry?草图去掉了一个角Cornerremovedfromsketch用来生成特征的草图做了修改将意味着包含这个特征的所有后续操作都