基于CATIA的汽車(chē)改裝式升降臺(tái)數(shù)字樣機(jī)建模及應(yīng)用研究中英文翻譯、外文文獻(xiàn)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(chē)改裝式升降臺(tái)數(shù)字樣機(jī)建模及應(yīng)用研究介紹了利用CATIAV5進(jìn)行機(jī)械零件i維造型以及零、部件虛擬裝配的基本過(guò)程與步驟，并以蝸輪蝸桿裝配為例進(jìn)行詳細(xì)說(shuō)明。對(duì)于改善機(jī)械設(shè)計(jì)的效果、提升設(shè)計(jì)效率、縮短設(shè)計(jì)加工周期，具有一定的現(xiàn)實(shí)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(guó)際航空工業(yè)首選的設(shè)計(jì)軟件。它以其強(qiáng)大的曲面設(shè)計(jì)功能在機(jī)械、飛機(jī)、汽車(chē)、造船等設(shè)計(jì)領(lǐng)域得到廣泛應(yīng)用，CATIA的曲面造型功能的特點(diǎn)和優(yōu)勢(shì)體現(xiàn)在它提供了極豐富的造型工具來(lái)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(dá)到15，能很好地滿足特殊行業(yè)對(duì)曲面光滑性的苛刻要求。應(yīng)用CATlA構(gòu)造的實(shí)體模型可直接應(yīng)用于ANSYS等分析軟件中進(jìn)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(tái)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(shí)間。零件裝配是CATIA基本的、也是最具優(yōu)勢(shì)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(dòng)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(jì)

草圖設(shè)計(jì)是三維設(shè)計(jì)的起點(diǎn)，其實(shí)質(zhì)是二維線、面設(shè)計(jì)，具有傳統(tǒng)二維軟件設(shè)計(jì)的功能。參數(shù)化設(shè)計(jì)的基本方法是從草圖設(shè)計(jì)開(kāi)始，通過(guò)施加尺寸和幾何約束生成草圖特征，再應(yīng)用尺寸驅(qū)動(dòng)技術(shù)自動(dòng)生成零件的三維實(shí)體模型，在利用草圖技術(shù)生成二維輪廓時(shí)不必輸入輪廓的準(zhǔn)確尺寸，可以在以后的參數(shù)設(shè)計(jì)過(guò)程中得到。這樣，在進(jìn)行產(chǎn)品設(shè)計(jì)時(shí)，可以隨時(shí)根據(jù)需要調(diào)整設(shè)計(jì)尺寸，而不必在設(shè)計(jì)之初就明確各設(shè)計(jì)尺寸，增強(qiáng)了CAD軟件的易操作性，更好地實(shí)現(xiàn)了人性化設(shè)計(jì)，而且對(duì)于設(shè)計(jì)系列產(chǎn)品及原產(chǎn)品的改進(jìn)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(qiáng)的三維實(shí)體建模的功能，當(dāng)用戶在草圖平面繪制二維圖形后，進(jìn)入零件設(shè)計(jì)(PartDesign)模塊，可以通過(guò)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(shí)還可利用參數(shù)化約束功能，根據(jù)需要隨時(shí)進(jìn)行修改。設(shè)計(jì)者可以直接針對(duì)零件毛坯進(jìn)行形體改變，實(shí)現(xiàn)了設(shè)計(jì)過(guò)程由"繪圖"向"設(shè)計(jì)"的轉(zhuǎn)變，而且CATIAV5提供的各項(xiàng)具體功能使三維模型的設(shè)計(jì)更類(lèi)似于生產(chǎn)加工過(guò)程，較好地實(shí)現(xiàn)設(shè)計(jì)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(jì)，即將特征作為設(shè)計(jì)的單元，將產(chǎn)品視為特征的有機(jī)結(jié)合，通過(guò)由類(lèi)到對(duì)象的逐步描述來(lái)實(shí)現(xiàn)具體的形狀設(shè)計(jì)。在生成三維零件毛坯后，可利用打孔、開(kāi)槽、抽殼、倒角、加凸臺(tái)、內(nèi)外螺紋等T具對(duì)"毛坯"進(jìn)行"加工"，最終完成機(jī)械零件實(shí)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(jì)算機(jī)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(duì)零部件進(jìn)行間隙和干涉檢驗(yàn)，減少樣品差錯(cuò)率。能在產(chǎn)品設(shè)計(jì)過(guò)程中利用各種技術(shù)手段如分析、評(píng)價(jià)、仿真等，并充分考慮產(chǎn)品的裝配環(huán)節(jié)及其相關(guān)過(guò)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(jìn)產(chǎn)品的裝配結(jié)構(gòu)，使設(shè)計(jì)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(jì)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(kāi)發(fā)方法，本文重點(diǎn)介紹自下而上的設(shè)計(jì)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(shí)際配合關(guān)系量化為虛擬裝配過(guò)程中的各零部件實(shí)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(guò)程中被利用，而并不是簡(jiǎn)單地被復(fù)制到裝配中，真正地實(shí)現(xiàn)了零件的"虛擬"裝配。

CATIA的裝配工作臺(tái)提供靈活、直觀的工具，用來(lái)確定各零件間的關(guān)系。裝配工作臺(tái)允許用戶將各個(gè)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(kù)的特性，不管如何編輯零部件和在何處編輯零部件，整個(gè)裝配部件保持關(guān)聯(lián)的一致性，如果修改整個(gè)零部件，則引用它的裝配件自動(dòng)更新，實(shí)時(shí)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(tái)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(duì)零部件進(jìn)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(jìn)行裝配的過(guò)程中已經(jīng)自動(dòng)建立了2個(gè)待裝配零件各自的設(shè)計(jì)基準(zhǔn)點(diǎn)的重合關(guān)系，便于設(shè)計(jì)者