外文翻译--机械工程设计选材基础知识.doc

英文原文Aknowledge-basedsystemformaterialsselectioninmechanicalengineeringdesignAbstractThispaperstudiesvariousworkonthedevelopmentofcomputerizedmaterialselectionsystem.TheimportanceofKnowledge-basedsystem(KBS)inthecontextofconcurrentengineeringisexplained.ThestudyofKBSinmaterialselectioninanengineeringdesignprocessisdescribed.Thedevelopmentinmaterialsdatabases,whichsometimesserveasmaterialselectionpackages,isalsodiscussed.TheuseofKBSinmaterialselectionandtheapplicationinthedomainofpolymeric-basedcompositearechosenastypicalexamples.2001PublishedbyElsevierScienceLtd.IntroductionMaterialsselectionisatasknormallycarriedoutbydesignandmaterialsengineers.GutteridgeandWater-man1describedtheaimofmaterialsselectionastheidentificationofmaterials,whichafterappropriatemanufacturingoperations,willhavethedimensions,shapeandpropertiesnecessaryfortheproductorcomponenttodemonstrateitsrequiredfunctionatthelowestcost.Forthepurposeofmaterialselection,thousandsofdatawouldbeneededtocharacterizeallthegradesofmaterials.Manyselectionsystemsareavailabletohelpdesignengineerstochoosethemostsuitablematerials.Atthemostbasiclevel,designengineerscouldusetablesofmaterialpropertiesindatabooks.However,datasheetsareincompleteandoncepublished,theyaredifficulttoupdate.DaddandFair-full2describedhowinformationaboutengineeringmaterials,canbedividedintotwomaincategories,i.e.dataandknowledge.Dataisdefinedastheresultsofmeasurements,whereasknowledgerepresentstheconnectionsbetweenitemsofdata,thesourceofthisknowledge,whichcontributestoanunderstandingoftheresults.BoththecomputerizeddatabaseandtheKBSofmaterialselectionwillbedescribedinthefollowingsections.Thematerialdatabaseformaterialsselection2.1.Supportingdataandrigorouslogicforthehypothesisandobservation.Inrecentyears,attentionisbeingmadetotheuseofcomputersystemstostoreandprocessdataregardingthepropertiesofmaterials.Itenablesthedesignerstoachievelargecapacityandrapidretrievalfromacomputerdatabasetoprovideeasyaccesstothematerialsdata.AccordingtoPrada3,materialsarethecommonelementsenumeratingpartsinaproductrealizationprocess.Nowadays,designengineersnormallyrelyonthematerialsthattheyarefamiliarwith.However,whendesignrequirementsexceedtheconstraintsofsuchmaterialsorexceedtheconstraintsonmaterialproperties,concurrentengineeringteamsmustconsideralternativematerials.Withdirectonlineaccesstoamaterialsdatabase,theconcurrentengineeringteamscouldselectmaterialsthatarelighter,strongerandlowerincost.Assumingthattheimpactofsuchsubstitutionscanbeanalyzedorsimulated,theteamscouldeasilymakeanoptimumselectionofmaterialsfortheavailableprocesses,conservematerialsforeachprocessandthus,reducematerialwaste.White4emphasizedtheimportanceofcomputeraidedmaterialsselectionasbookshaveseveraldrawbacksastheyareoftenoutdatedbeforereachingthebookshelves.Itisverydifficulttoindexthemtofindanswersortosortdatainthemannerofyourchoice.Acomputerizedsystem,whichprovidesaccesstomaterialsdata,isnotnecessarilyamaterialsselectionsystem,althoughaccesstodataisessentialtofacilitateselection.2.2.CriticalreviewThissectionreviewsthedevelopmentofcomputerizedmaterialsdatabasesthatenableddesignerstoselectthematerialsinmechanicalengineeringdesignapplication.ThedevelopmentofmaterialdatabaseshasbeenreportedbyHarmer5,Breueretal6-10,Baur11-12,Michael13,Ashby14-15andCebonandAshby16-17.Harmer5reportedthatvariousdatabasesystemshavebeendevelopedforplastics,elastomersandrubberssuchastheCambridgeMaterialsSelector(CMS),CAMPUS,SelectorII,Specula,Cen-base/Materials,Mat.DB,PlasticsDesignLibrary.EngineeredMaterialsAbstracts,FUNDUS,ProspectorPlus,Polymat,SPAO,Pro-Concept,Explorer,Platapolymerically,StandardsInfo-disk,PiuraAbstracts,PackagingScienceandTechnologyAbstracts,Chem-In-tellandWelda-search.Computer-aidedmaterialpre-selectionbyuniformstandards(CAMPUS)isawidelyusedmaterialsdatabaseforplastics6-10.AproductsimilartothatofCAMPUSisadatabaseconcernedwiththeselectionoflongfiberreinforcedplastics.ThissystemiscalledFUNDUSanditallowsthedistributionofmaterialinformationfromtheproducertothedesignerend-user11-13.Assuch,itisofinteresttoallwhoworkwithsheetmoldingcompound(SMC),bulkmoldingcompound?.BMCorglass-matthermoplastic(GMT)materialsasreportedbyBaur11-12andMichaelietal.13.CAMPUSandFUNDUShavefeatures,whichallowtheusertoviewallpropertiesforanylistedproduct,printthedataforanyproductsearchthedatabaseforproductssatisfyingspecificpropertyrequirements,selectandviewpropertiesforcomparison,andsortaccordingtospecificrequirementinascendingordescendingorder.Ashby14,15andCebonandAshby16-17developedacomputerizedmaterialsselectionsystemcalledCambridgeMaterialsSelector(CMS).Thesystemusesmaterialsselectioncharts,whichareawayofdisplayingmaterialpropertydatathroughtheuseofoptimizationprocedures.TheselectionprocessdependsonimplementingperformanceIndices,acombinationofmaterialproperties,whichifmaximized,optimizesperformance.Thechartsaredevelopedtopresentthematerials,andtheperformanceIndices,sothatthemostsuitableselectionofmaterialsandshapecanbecarriedout.MachineDesignThecompletedesignofamachineisacomplexprocess.Themachinedesignisacreativework.Projectengineernotonlymusthavethecreativityinthework,butalsomustinaspectandsoonmechanicaldrawing,kinematics,engineeringmaterial,materialsmechanicsandmachinemanufacturetechnologyhasthedeepelementaryknowledge.Oneofthefirststepsinthedesignofanyproductistoselectthematerialfromwhicheachpartistobemade.Numerousmaterialsareavailabletotodaysdesigners.Thefunctionoftheproduct,itsappearance,thecostofthematerial,andthecostoffabricationareimportantinmakingaselection.Acarefulevaluationofthepropertiesofa.materialmustbemadepriortoanycalculations.Carefulcalculationsarenecessarytoensurethevalidityofadesign.Incaseofanypartfailures,itisdesirabletoknowwhatwasdoneinoriginallydesigningthedefectivecomponents.Thecheckingofcalculations(anddrawingdimensions)isofutmostimportance.Themisplacementofonedecimalpointcanruinanotherwiseacceptableproject.Allaspectsofdesignworkshouldbecheckedandrechecked.Thecomputerisatoolhelpfultomechanicaldesignerstolightentediouscalculations,andprovideextendedanalysisofavailabledata.Interactivesystems,basedoncomputercapabilities,havemadepossibletheconceptsofcomputeraideddesign(CAD)andcomputer-aidedmanufacturing(CAM).Howdoesthepsychologistfrequentlydiscusscausesthemachinewhichthepeopleadaptsthemtooperate.Designspersonnelsbasicresponsibilityisdiligentlycausesthemachinetoadaptthepeople.Thiscertainlyisnotaneasywork,becausecertainlydoesnothavetoallpeopletosayinfactallisthemostsuperioroperatingareaandtheoperatingprocess.Anotherimportantquestion,projectengineermustbeabletocarryontheexchangeandtheconsultationwithotherconcernedpersonnel.Intheinitialstage,designsthepersonneltohavetocarryontheexchangeandtheconsultationonthepreliminarydesignwiththeadministrativepersonnel,andisapproved.Thisgenerallyisthroughtheoraldiscussion,theschematicdiagramandthewritingmaterialcarrieson.Iffrontsues,themachinedesigngoalistheproductioncanmeetthehumanneedtheproduct.Theinvention,thediscoveryandtechnicalknowledgeitselfcertainlynotnecessarilycanbringtheadvantagetothehumanity,onlyhaswhentheyareappliedcanproduceontheproductthebenefit.Thus,shouldrealizetocarriesonbeforethedesigninaspecificproduct,mustfirstdeterminewhetherthepeopledoneedthiskindofproductMustregardasthemachinedesignisthemachinedesignpersonnelcarriesonusingcreativeabilitytheproductdesign,thesystemanalysisandaformulationproductmanufacturetechnologygoodopportunity.Graspstheprojectelementaryknowledgetohavetomemorizesomedataandtheformulaismoreimportantthan.Themerelyservicedataandtheformulaisinsufficienttothecompletelydecisionwhichmakesinagooddesignneeds.Ontheotherhand,shouldbeearnestpreciselycarriesonalloperations.Forexample,evenifplaceswrongadecimalpointposition,alsocancausethecorrectdesigntoturnwrongly.Agooddesignpersonnelshoulddaretoproposethenewidea,moreoveriswillingtoundertakethecertainrisk,whenthenewmethodisnotsuitable,useoriginalmethod.Therefore,designsthepersonneltohavetohavetohavethepatience,becausespendsthetimeandtheendeavorcertainlycannotguaranteebringssuccessfully.Abrand-newdesign,therequestscreenabandonsobsoletelymany,knowsverywellthemethodforthepeople.Becausemanypersonofconservativeness,doesthiscertainlyisnotaneasymatter.Amechanicaldesignershouldunceasinglyexploretheimprovementexistingproductthemethod,shouldearnestlychooseoriginally,theprocessconfirmationprincipleofdesigninthisprocess,withhasnotunifieditaftertheconfirmationnewidea.中文译文机械工程设计选材基础知识摘要本文致力于研究对各种材料选择的电脑化系统发展。并对以基础知识的系统在并行工程环境（KBS）的重要性进行了解释。KBS的研究在材料选择方面由一个工程设计过程来描述。材料数据库的发展，和选材服务，也被讨论到了。在材料选择KBS和使用中的聚合物基复合材料领域的应用是选材典型的例子。2001年由Else-vier科学有限公司出版。1.简介材料选择通常是设计和材料工程师一项任务。加特里奇和水人1中是这样描述选择材料的:经过适当的制造业务，将有尺寸，形状和性能的产品或组件要以最低的成本展示其规定功能的材料选择的目标。对于选材的目的，成千上万的数据将需要所有的材料的特性。许多选择系统可以帮助设计工程师选择最合适的材料。在最基本的层面上，设计工程师可利用材料性能数据手册表。但是，数据表是不完整的，一旦公布，他们是难以更新。多德和范福2描述了有关工程材料的资料，可分为两大类，即数据和知识的分歧。数据被定义为测量的结果，而信息代表之间的数据，在这方面的知识，这有助于对结果的认识源项目的连接。无论是计算机化的数据库和材料选择的KBS将在以下各节描述。2.针对对材料选择的材料数据库2.1支持这一假设的数据和严密的逻辑近年来，关注正在面向计算机系统来存储和处理数据的有关材料的性能。它使得设计者能够在实现大容量和快速的从一个计算机数据库里检索到资料数据。据普拉萨德3，材料是在列举部分产品实现过程的共同要素。如今，设计工程师通常依赖于材料，他们所熟悉的。然而，当超过设计要求这些材料的限制或超过材料特性的限制，并行工程团队必须考虑替代材料。随着直接在线访问材料数据库，并行工程团队可以选择的材料，重量更轻，更强，成本更低。假设，这种替代的影响可以分析或模拟，团队可以轻而易举地把一个可用进程的最佳选择材料，节约每一个程序的材料，因此，减少材料浪费是必须的。白4强调了计算机选型辅助材料的重要性，图书有几个缺点，他们往往在到达的书架得时候已经过时。这使得他们很难找到答案指标进行排序或在您选择的方式的数据。电脑化系统，它提供了访问数据的材料，并不一定是材料选择系统，虽然对数据的访问是必要的，以方便选择。