基于CATIA的汽車改裝式升降臺數(shù)字樣機建模及應(yīng)用研究中英文翻譯、外文文獻翻譯、外文翻譯

附錄附錄AModifiedCarLiftingPlatformBasedonCATIAModelingandApplicationofDigitalPrototypingDescribestheuseofCATIAV5mechanicalpartsiandzero-dimensionalmodeling,virtualassemblyofthebasicprocesscomponentsandsteps,andwormassembly,forexampleindetail.Theeffectofimprovingthemechanicaldesigntoimprovedesignefficiencyandshortenthedesigncycletime,hassomepracticalsignificance1OverviewCATIAsoftwarefromIBMandDassaultcompanytolaunchhigh-endCAD/CAMsoftware,hasbecometheinternationalaviationindustrypreferreddesignsoftware.Withitsstrongsurfacedesignfeaturesinthemachinery,aircraft,automobile,shipbuildingandotherwidelyuseddesign,CATIAsurfacemodelingcapabilitiesisreflectedinthefeaturesandadvantagesitprovidesaveryrichmodelingtoolstosupporttheusermodelingneeds.Asitsuniquehigh-orderBeziercurveandsurfacefeatures,thenumbercanreach15,canwellmeetspecificindustrydemandingrequirementsofsurfacesmoothness.ApplicationCATlAconstructedsolidmodelcanbedirectlyappliedtootheranalysissoftwareANSYSfiniteelementanalysisCATIAsoftwarewiththree-dimensionalCADsoftwareandotherstandarddatainterfaceforeasydataconversionmodel.CATIAV5isbasedontheWindowsplatform,andtofullyparametricfeaturemodelingtechnologyasthecorefeature-basedmodelingsoftware,whichisconsistentwiththeWindows-stylemenubar,standardshortcuts,contextualmenus,multi-documentinterface,youcanmakethedifferenceWindowsapplicationstosharedata,OLEintegration,soworkquicklyandefficiently,cansignificantlyreducetrainingtime.CATIApartsassemblyisbasic,butalsothemostadvantagesandfeaturesfunctionmodules,includingthecreationofanassembly,addthespecifiedcomponentsorpartstotheassembly,theassemblyrelationshipbetweencomponentstocreate,moveandlayoutoftheassemblymembers,generatedanexplosionofproductsdiagram,assemblyinterferenceandgapanalysisandothermajorfeatures?.2three-dimensionalmodelingbasedonCATIAandassembly2.1DesignsketchesSketchdesignisthestartingpointofthree-dimensionaldesign,anditsessenceisatwo-dimensionalline,surfacedesign,softwaredesignwithatraditionaltwo-dimensionalfunctions.Parametricdesignofthebasicapproachistostartfromscratchdesign,sizeandgeometricconstraintsimposedbycreatingasketchfeature,thenapplythesize-driventechnologytoautomaticallygeneratepartsofthethree-dimensionalsolidmodel,intheuseoftechnologytogeneratetwo-dimensionalcontoursketchesdonothavetooutlinetheexactsizeoftheinput,theparametersinthefuturetogetthedesignprocess.Thus,duringtheproductdesign,youcanalwaysadjustthedesignsize,withoutaclearearlyinthedesignofthedesignsize,enhancetheeaseofCADsoftware,tobetterachieveauser-friendlydesign,butalsoforthedesignofseriesimprovementofproductsandoriginalproductsandparts"borrowed"areconvenient.2.2togeneratethree-dimensionalpartblankCATIAhasastrongthree-dimensionalsolidmodelingfunctionality,theuserplaneinthesketch,afterdrawingtwo-dimensionalgraphics,intothepartdesign(PartDesign)modules,youcanrotate,stretch,lofting,stiffened,andothermethodstogeneratethedraftthree-dimensionalpartstoberough.Constraintscanalsouseparameterizedfunctionstobemodifiedaccordingtoneed.Designerscanchangeforthebodypartblanktoachievethedesignprocessby"drawing"to"design"changes,andCATIAV5providesthree-dimensionalmodelofthespecificfeaturesmakethedesignmoresimilartotheproductionprocess,bettertoachieveacombinationofdesignandprocessing.2.3completethethree-dimensionalmodelingCATIAV5providesfeature-baseddesign,willfeatureasadesignelement,thecharacteristicsoftheproductasacombination,throughtheobjectfromtheclasstobeachievedstepbystepdescriptionofthespecificshapeofthedesign.Aftergeneratingtheroughthree-dimensionalpartscanbeusedtodrilling,slotting,shells,chamfer,plusconvexsets,suchasTwithinternalandexternalthreadsonthe"rough"to"processing",thefinalcompletionofmechanicalpartssolidmodeling.2.4completethevirtualassemblyVirtualassemblyisusingvirtualassemblytechnology,three-dimensionalcomputermodelwillbeassembledtogether,itcanavoidtheapplicationofphysicalprototypes,butalsoforpartsforclearanceandinterferencetesting,reducethesampleerrorrate.Intheproductdesignprocesscanusevarioustechniquessuchasanalysis,evaluation,simulation,andgivefullconsiderationtotheassemblyareasandrelatedproductsduringthevariouspossiblefactors.Productperformanceandfunctionalitytomeettheconditionstoimprovetheproductassemblystructure,thedesignoftheproductnotonlyassembly,andminimizeassemblycostandtotalproductcosts,shortendesigncycles.CATIA-basedvirtualassemblymodelhasparallel,bottom-upandtop-downapproachtoproductdevelopment,thisarticlefocusesonbottom-updesign.Constructthefirstmoduleinthepartsofpartsofthethree-dimensionalmodel,thencomponentsintheassemblymoduletocreateconstraintsbetweentheposition,orientationrelationships,abouttherelationshipbetweenpartstoquantifytheactualwiththevirtualassemblyprocessbetweenthevariouscomponentsentitieslocationconstraintrelationship.Inthisway,partsofthegeometryisbeingusedintheassemblyprocess,andnotsimplybecopiedtotheassembly,totrulyrealizethepartofthe"virtual"assembly.CATIAassemblyworkbenchprovidesaflexibleandintuitivetooltodeterminetherelationshipbetweenparts.Workbenchallowsuserstoassemblethecomponentpartsandvarioussub-assembliescombinedtogethertoformthefinalassemblyintheassemblyenvironment,accordingtothedefinedconstraints,partscanbemodified,analysis,andrelocationHJ.CATIAfeatureswithasingledatabase,regardlessofhoweditorseditpartsandcomponentswherethewholeassemblyofpartstomaintaintheconsistencyofassociation,ifyoumodifythecomponents,assembliesthatreferenceitautomaticallyupdated,real-timecomponentsreflectthelatestchange.Virtualassemblysteps:theassemblyprovidedinCArllAbench,leadersneedtoassemblethepartsandcomponents(CATIAprovidesthemainmethodofinsertingpartsintoparts,intotheproducts,partsandinsertnewcomponentsintoexisting,etc.).Then,theconstraintsonthecomponentsandtheestablishmentofappropriateassemblyrelationship,accordingtotherequirementsofthedifferentpartsoftheassembly,useadifferentconstraintrelations,andfinallygetacompleteassemblymodel.AndPro/EcomparedtotheassemblyprocessusingCATIAhasautomaticallycreatedtwopartstobeassembledtheirdesignbasispointsofoverlapbetweencomponentstofacilitatethedesigneracleardesignbasisbetweentheassemblyandpartsbetweenthebasedifference.3DesignExampleThewormdrive,forexample,theuseofCATIAmodelingandassemblyprocessandmethodsdescribed.3.1tocreatethree-dimensionalmodelwormAnalysisofthestructureofthewormpart,clearlythemainfeaturesofthestructuretodeterminethemodelingsteps.Byrotatingthewormbody,composedofthealveolarandkeywayparts,thebasiccharacteristicsofarotatingbody.3.1.1Createthree-dimensionalmodelofthewormpart(1)indraftmodetodrawshapesaccordingtotheroughshapeofthewormroughsketches,theestablishmentofsizeconstraints,suchassizechanges,chamfer,etc.(ofcourse,alsointheformationofroughchamferaftertheentity).(2)Inthedesignmode,theuseofrotatingparts(Shaft)tooltogeneratewormblank.(3)Accordingtotheworm'sparameters,tocalculatethealveolarpitchwormandthewormscrewaccordingtothemodeofcurvesandsurfacesgeneratedawormwrappedaroundthespiral,astheslotscanningwire.(4)SincetheendofcylindricalwormArchimedesArchimedesspiral,obliqueaxialplanetoastraightline∞],sothewormshaftcanchoosealmostplane,indraftmode,drawatrapezoid(mustbeaclosedcurve),itsdistancefromtheaxisofthebottommarginisjustthewormtoothrootradius,bothsidesoftheedgeandfaceangleof20.(Note:Thepitchatbothsidesoftheedgedistanceshouldbethepitchcirclespacewidth).(5)inthepartdesignmodeusingthenarrowslot(Slot)tooltogenerateanalveolar;usethewholearrayoftoolstowormoutofthealveolarprocess.(6)indraftmodetodrawshapeskeyway,theuseofstretchcutting(Pocket)tooltogeneratekeyslot,tocompletethethree-dimensionalconstructionofthewormMode.3.1.2createthree-dimensionalmodelwormpartsAnalysisofwormpartsofthestructure,clearlyamajorcomponentcharacteristicstodeterminethemodelingsteps.Asthewormgearandringgearteethbythecore2parts,sotheringgearandthetoothshouldbeseparatedfromthecoremodel,andthenassembled.PartsusingCATIAmodelingplatformprovidedbytheringgearandthewormweregeneratedtoothcore.3.2partsoftheassembly3.2.1ImportPartsAssemblyinCATIAprovidestheproductstructureworkbenchtoolbar,useofexistingpartsintothefunctionofthepriorconductivityhasbeendesignedwormandwormparts.3.2.2theestablishmentofbindingAspartoftheimportprocessCAITAhasestablishedaworminthewormandtheaxialprofilewidthof1/2ofthefaceoverlapconstraintrelations,haspledgeditsprofileinthewormdriveofthemain(centersection)onthealignment,inTheonlyothertwotodeterminethedirectionoftheconstraintrelationship.Centerdistancewormgearinaccordancewithrequirements(centerdistancewormandwormgearduringphysicalmodeling,basedonthegeometricparametersofwormandwormcalculated),theestablishmentofthewormandwormwheelaxisoffsetbetweentheaxisofrestrainttoensurethatthedifferencebetweenthedistancetomeetthedesignrequirements.Alongtheaxisofthewormtoestablishwormconstraintrelation,whichistoensure"inthemiddleofthewormandwormgearwormsideoftheaxisofsymmetryperpendiculartotheplane"and"wormwidth1/2symmetryonthealveolarsurfaceprofile"coincidence(Note:duringthewormandwormwheelsolidmodelingcalculationsmustbeaccurate,otherwiseitwillnotbeaccuratewormandwormwheelworkingposition)toensurethatthewormandwormgearinstalledinthecorrespondingposition.GeneratedasshowninFigure1wormdriveassemblymodel.4ConclusionCATIA3Ddesignsoftwaredesigntoolsprovideacompleteandconvenientuserinterface,theinterfaceandoptionsdesignedwithaconsistentstylewithMicrosoftproducts,greatlyreducingtheuserforthesoftwaretolearnandadapttothecycle,toalargeextentimprovedtheoperationofcomplex3Dmodelingsoftwaredefects.Meanwhile,CATIAfeature-based3Dmodelingfunctionsithasthefollowingadvantages:(1)inheritedtheuseofsolidmodelingsoftwareforproductdesign,theusercandirectlyseeonthescreenthetruethree-dimensionalmodeloftheproductcharacteristics,tomodeltheirideasclosertothebodycomposition,moreintuitivedesign.(2)parametricdesignchangestofacilitatethegraphicsize,quicklyplotted,relativetothetwo-dimensionalgraphicsmethods,designedtogreatlyreducetheworkload,especiallyinthesubsequentparametricdesignforthetechnicalstaffprovidesaneasydesign,easytomodifytheplatform,facilitatingproductserialdesign.(3)Thefeature-basedmodelingidea,theuseofBooleanoperatorsseekingintersectinglines,intersectinglines,theengineeringdrawingspeedfaster,moreaccurateline.(4)assemblymethodusingavirtualmachine,youcandirectlychecktheproductdesignspacemechanicalsystemcomponentsandassemblyofinterferenceandtofurthervisualizethedesignandanalysis,concurrentengineeringhasacertainsignificance.

附錄B基于CATIA的汽車改裝式升降臺數(shù)字樣機建模及應(yīng)用研究介紹了利用CATIAV5進行機械零件i維造型以及零、部件虛擬裝配的基本過程與步驟，并以蝸輪蝸桿裝配為例進行詳細說明。對于改善機械設(shè)計的效果、提升設(shè)計效率、縮短設(shè)計加工周期，具有一定的現(xiàn)實意義1概述

CATIA軟件是IBM公司和Dassault公司合作推出的高端CAD／CAM軟件，現(xiàn)已成為國際航空工業(yè)首選的設(shè)計軟件。它以其強大的曲面設(shè)計功能在機械、飛機、汽車、造船等設(shè)計領(lǐng)域得到廣泛應(yīng)用，CATIA的曲面造型功能的特點和優(yōu)勢體現(xiàn)在它提供了極豐富的造型工具來支持用戶的造型需求。如其特有的高次Bezier曲線曲面功能，次數(shù)能達到15，能很好地滿足特殊行業(yè)對曲面光滑性的苛刻要求。應(yīng)用CATlA構(gòu)造的實體模型可直接應(yīng)用于ANSYS等分析軟件中進行有限元分析。CATIA軟件具有與其他三維CAD軟件標(biāo)準(zhǔn)的數(shù)據(jù)接口，方便模型數(shù)據(jù)的轉(zhuǎn)換。

CATIAV5是基于Windows平臺的全參數(shù)化和以特征建模技術(shù)為核心的特征造型軟件，它與Windows保持一致風(fēng)格的菜單條、標(biāo)準(zhǔn)的快捷鍵、上下關(guān)聯(lián)的菜單、多文檔界面、可以使不同的Windows應(yīng)用程序共享數(shù)據(jù)的OLE集成，使工作快速高效，可顯著減少培訓(xùn)時間。零件裝配是CATIA基本的、也是最具優(yōu)勢和特色的功能模塊，包括創(chuàng)建裝配體、添加指定的部件或零件到裝配體、創(chuàng)建部件之間的裝配關(guān)系、移動和布置裝配成員、生成產(chǎn)品的爆炸圖、裝配干涉和間隙分析等主要功能?。

2基于CATIA的三維造型與裝配

2．1草圖設(shè)計

草圖設(shè)計是三維設(shè)計的起點，其實質(zhì)是二維線、面設(shè)計，具有傳統(tǒng)二維軟件設(shè)計的功能。參數(shù)化設(shè)計的基本方法是從草圖設(shè)計開始，通過施加尺寸和幾何約束生成草圖特征，再應(yīng)用尺寸驅(qū)動技術(shù)自動生成零件的三維實體模型，在利用草圖技術(shù)生成二維輪廓時不必輸入輪廓的準(zhǔn)確尺寸，可以在以后的參數(shù)設(shè)計過程中得到。這樣，在進行產(chǎn)品設(shè)計時，可以隨時根據(jù)需要調(diào)整設(shè)計尺寸，而不必在設(shè)計之初就明確各設(shè)計尺寸，增強了CAD軟件的易操作性，更好地實現(xiàn)了人性化設(shè)計，而且對于設(shè)計系列產(chǎn)品及原產(chǎn)品的改進和零部件的"借用"都方便。

2．2生成三維零件毛坯

CATIA具有很強的三維實體建模的功能，當(dāng)用戶在草圖平面繪制二維圖形后，進入零件設(shè)計(PartDesign)模塊，可以通過旋轉(zhuǎn)、拉伸、放樣、加肋、拔模等方法生成所需的三維零件毛坯。同時還可利用參數(shù)化約束功能，根據(jù)需要隨時進行修改。設(shè)計者可以直接針對零件毛坯進行形體改變，實現(xiàn)了設(shè)計過程由"繪圖"向"設(shè)計"的轉(zhuǎn)變，而且CATIAV5提供的各項具體功能使三維模型的設(shè)計更類似于生產(chǎn)加工過程，較好地實現(xiàn)設(shè)計與加工的結(jié)合。

2．3完成三維造型

CATIAV5提供基于特征的設(shè)計，即將特征作為設(shè)計的單元，將產(chǎn)品視為特征的有機結(jié)合，通過由類到對象的逐步描述來實現(xiàn)具體的形狀設(shè)計。在生成三維零件毛坯后，可利用打孔、開槽、抽殼、倒角、加凸臺、內(nèi)外螺紋等T具對"毛坯"進行"加工"，最終完成機械零件實體造型。

2．4完成虛擬裝配

虛擬裝配是利用虛擬裝配技術(shù)，在計算機上將三維模型裝配到一起，這樣可避免物理原型的應(yīng)用，也可對零部件進行間隙和干涉檢驗，減少樣品差錯率。能在產(chǎn)品設(shè)計過程中利用各種技術(shù)手段如分析、評價、仿真等，并充分考慮產(chǎn)品的裝配環(huán)節(jié)及其相關(guān)過程中各種可能因素的影響。在滿足產(chǎn)品性能與功能的條件下改進產(chǎn)品的裝配結(jié)構(gòu)，使設(shè)計出的產(chǎn)品不但可以裝配，并盡可能降低裝配成本和產(chǎn)品總成本，大大縮短設(shè)計周期。

基于CATIA的虛擬裝配模式有并行、自下而上和自上而下的產(chǎn)品開發(fā)方法，本文重點介紹自下而上的設(shè)計方法。先在零件模塊中構(gòu)造各零件的三維模型，然后在裝配模塊中建立零部件之間的位置約束、定位關(guān)系，即將零件間的實際配合關(guān)系量化為虛擬裝配過程中的各零部件實體之間的位置約束關(guān)系。這樣，零部件的幾何體是在裝配過程中被利用，而并不是簡單地被復(fù)制到裝配中，真正地實現(xiàn)了零件的"虛擬"裝配。

CATIA的裝配工作臺提供靈活、直觀的工具，用來確定各零件間的關(guān)系。裝配工作臺允許用戶將各個組成零件和各種子裝配件組合到一起形成最終的裝配體，在裝配環(huán)境中，根據(jù)定義的約束，零件可以被修改、分析以及重定位HJ。CATIA具有單一數(shù)據(jù)庫的特性，不管如何編輯零部件和在何處編輯零部件，整個裝配部件保持關(guān)聯(lián)的一致性，如果修改整個零部件，則引用它的裝配件自動更新，實時反映零部件的最新變化。虛擬裝配的步驟：在CArllA所提供的裝配工作臺上，導(dǎo)人需裝配的零、部件(CATIA提供的插入部件的方法主要有插入部件、插入產(chǎn)品、插入新部件和插入已存在的部件等)。然后，對零部件進行適當(dāng)?shù)募s束并建立裝配關(guān)系，根據(jù)不同零件的裝配要求，選用不同的約束關(guān)系，最后得到完整裝配模型。

與Pro／E相比，使用CATIA進行裝配的過程中已經(jīng)自動建立了2個待裝配零件各自的設(shè)計基準(zhǔn)點的重合關(guān)系，便于設(shè)計者