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试验 实验 发动机 压力 测试 装置 设计

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毕业设计（论文）-试验发动机压力测试装置设计,试验,实验,发动机,压力,测试,装置,设计

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【外文资料原文】MULTIOBJECTIVEOPTIMALFIXTURELAYOUTDESIGNINADISCRETEDOMAINABSTRACTTHISPAPERADDRESSESAMAJORISSUEINFIXTURELAYOUTDESIGNTOEVALUATETHEACCEPTABLEFIXTUREDESIGNSBASEDONSEVERALQUALITYCRITERIAANDTOSELECTANOPTIMALFIXTUREAPPROPRIATEWITHPRACTICALDEMANDSTHEPERFORMANCEOBJECTIVESCONSIDEREDARERELATEDTOTHEFUNDAMENTALREQUIREMENTSOFKINEMATICLOCALIZATIONANDTOTALFIXTURINGFORMCLOSUREANDAREDEFINEDASTHEWORKPIECELOCALIZATIONACCURACYANDTHENORMANDDISTRIBUTIONOFTHELOCATORCONTACTFORCESANEFFICIENTINTERCHANGEALGORITHMISUAEDINAMULTIPLECRITERIAOPTIMIZATIONPROCESSFORDIFFERENTPRACTICALCASES,LEADINGTOPROPERTRADEOFFSTRATEGIESFORPERFORMINGFIXTURESYNTHESISIINTRODUCTIONPROPERFIXTUREDESIGNISCRUCIALTOPRODUCTQUALITYINTERMSOFPRECISIONANDACCURACYINPARTFABRICATIONANDASSEMBLYFIXTURINGSYSTEMS,USUALLYCONSISTINGOFCLAMPSANDLOCATORS,MUSTBECAPABLETOASSURECERTAINQUALITYPERFORMANCES,BESIDESOFPOSITIONINGANDHOLDINGTHEWORKPIECETHROUGHOUTALLTHEMACHININGOPERATIONSALTHOUGHTHEREAREAFEWDESIGNGUIDELINESSUCHAS321RULE,AUTOMATEDSYSTEMSFORDESIGNINGFIXTURESBASEDONCADMODELSHAVEBEENSLOWTOEVOLVETHISARTICLEDESCRIBESARESEARCHAPPROACHTOAUTOMATEDDESIGNOFACLASSOFFIXTURESFOR3DWORKPIECESTHEPARTSCONSIDEREDTOBEFIXTUREDPRESENTANARBITRARYCOMPLEXGEOMETRY,ANDTHEDESIGNEDFIXTURESARELIMITEDTOTHEMINIMUMNUMBEROFELEMENTSREQUIRED,IESIXLOCATORSANDACLAMPFURTHERMORE,THEFIXELSAREMODELEDASNONFRICTIONALPOINTCONTACTSANDARERESTRICTEDTOBEAPPLIEDWITHINAGIVENCOLLECTIONOFDISCRETECANDIDATELOCATIONSINGENERAL,THESETOFFIXTURELOCATIONSAVAILABLEISASSUMEDTOBEAPOTENTIALLYVERYLARGECOLLECTIONFOREXAMPLE,THELOCATIONSMIGHTBEGENERATEDBYDISCRETIZINGTHEEXTERIORSURFACESOFTHEWORKPIECETHEGOALOFTHEFIXTUREDESIGNISTODETERMINEFIRST,FROMTHEPROPOSEDDISCRETEDOMAIN,THEFEASIBLEFIXTURECONFIGURATIONSTHATSATISFYTHEFORMCLOSURECONSTRAINTSECONDLY,THESETSOFACCEPTABLEFIXTUREDESIGNSAREEVALUATEDONSEVERALCRITERIAANDOPTIMALFIXTURESARESELECTEDTHEPERFORMANCEMEASURESCONSIDEREDINTHISWORKARETHELOCALIZATIONACCURACY,ANDTHENORMANDDISTRIBUTIONOFTHELOCATORCONTACTFORCESTHESEOBJECTIVESCOVERTHEMOSTCRITICALERRORSOURCESENCOUNTEREDINAFIXTUREDESIGN,THEPOSITIONERRORSANDTHEUNWANTEDSTRESSINTHEPARTFIXTUREELEMENTSDUETOANOVERLOADEDORUNBALANCEDFORCESYSTEMTHEOPTIMALFIXTUREDESIGNAPPROACHISBASEDONACONCEPTOFOPTIMUMEXPERIMENTDESIGNTHEALGORITHMDEVELOPEDEVALUATESEFFICIENTLYTHEADMISSIBLEDESIGNSEXPLOITINGTHERECURSIVEPROPERTIESINLOCALIZATIONANDFORCEANALYSISTHEALGORITHMPRODUCESTHEOPTIMALFIXTUREDESIGNTHATMEETSASETOFMULTIPLEPERFORMANCEREQUIREMENTSIIMULTIOBJECTIVEFIXTURELOCATOROPTIMIZATIONINMANYAPPLICATIONSTHECLAMPISALREADYFIXEDGIVENSOMEPRACTICALCONSIDERATIONSTHENWITHTHECLAMPPREDEFINED,THEBESTFIXTUREWITHRESPECTTOACERTAINPERFORMANCECRITERIONISCONSTRUCTEDBYSELECTINGASUITABLESETOFLOCATORSSUCHTHATASIGNIFICANTIMPROVEMENTOFTHEOBJECTIVEFUNCTIONISREGISTEREDUSINGTHERANDOMINTERCHANGEALGORITHMWECANANALYZETHEIMPACTOFTHEOPTIMIZATIONPROCESSONTHEFIXTURECHARACTERISTICS,ASWELLASWECANSELECTTHEBESTOPTIMIZEDFIXTURESOLUTIONFORASPECIFICCRITERIONINANALYZINGTHEEFFECTOFRANDOMINTERCHANGEALGORITHMONSEVERALPARTS,THERECANBEMADETHEFOLLOWINGSTATISTICALANDEMPIRICALOBSERVATIONSIIIOPTIMALFIXTURECLAMPINGTHISSECTIONDEALSWITHAMORECOMPLICATEDPROBLEMTOSEARCHSIMULTANEOUSLYFORTHEOPTIMALCLAMPANDLOCATORSINORDERTOACHIEVEAREQUIREDFIXTUREQUALITYVARYINGTHECLAMP,ITISOBVIOUSTHATTHENUMBEROFCOMBINATIONSFORPOSSIBLECLAMPLOCATORSCANDIDATESISINCREASINGVERYMUCHITWILLBESHOWNTHATTHISPROBLEMISMANAGEABLEFORTHEPRECISELOCALIZATIONOBJECTIVEFORTHEOTHEROBJECTIVESWEWILLHAVETORESTRAINTHESEARCHOFTHEOPTIMALCLAMPINSIDEOFASMALLSETOFPROPOSEDLOCATIONS,SUCHTHATTHEOPTIMIZATIONPROCEDURECOULDBEHANDLEDIVCONCLUSIONSTHISARTICLEFOCUSESONOPTIMALDESIGNOFFIXTURELAYOUTFOR3DWORKPIECESWITHANOPTIMALRANDOMINTERCHANGEALGORITHMTHEQUALITYOBJECTIVESCONSIDEREDINCLUDEACCURATEWORKPIECELOCALIZATION,MINIMALANDBALANCEDCONTACTFORCESTHEPAPERFOCUSESONMULTICRITERIAOPTIMALDESIGNWITHAHIERARCHICALAPPROACHANDACOMBINEDOBJECTIVEAPPROACHTHEOPTIMIZATIONPROCESSESMAKEUSEOFANEFFICIENTINTERCHANGEALGORITHMEXAMPLESAREUSEDTOILLUSTRATEEMPIRICALOBSERVATIONSWITHRESPECTTOTHEDESIGNAPPROACHESANDTHEIREFFECTIVENESSTHEWORKDESCRIBEDHEREISYETCOMPLETESINCETHEINTERRELATIONSHIPBETWEENTHELOCATORSANDTHECLAMPSHASADETERMINANTROLEONTHEFIXTUREQUALITYMEASURES,AMORECOHERENTANDCOMPLETEAPPROACHTOSTUDYTHEINFLUENCEOFTHECLAMPANDSEARCHOFTHEOPTIMALCLAMPPOSITIONISNEEDEDINFUTUREWORKS在独自领域最佳多功能夹具布置的设计摘要本文论及一个在夹具布置设计的重要问题根据实用要求来选择一套优化的装置，并评估可接受的装置设计。主要宗旨是要考虑与根本要求有关的运动学方面和总的夹具形式形式闭，还要考虑作为工件定位的准确性和标准以及定位布置的联系。高效率的互换算法被使用在多标准优化过程有很多不同的实用案件,因此合适的交换平台能执行综合装置。1简介适当的夹具设计对产品质量方面精确度和准确性在部份制造和装配是关键的夹具系统,通常包括钳位和定位器,必须是可胜任保证成品质量包括安置和保证在机器生产中的加工过程虽然有几个设计指南如321规则,自动化的系统为设计夹具提供的CAD模型在演变。这是一篇描述自动设计夹具之类的3D研究方法文章这部分被认为是固定当前任意复杂几何,并且被设计的夹具必需限制在对元素的最小数字,即六台定位器和钳位。此外,固定器被限制在无非摩擦点接触并且实用的位置总之,夹具之类必需放在假定的潜在准确的位置例如,位置也许由可分辨的工件外表面决定的。首先确定夹具设计的目的,从被提出的的特殊领域,在这个领域可行的夹具设计必需满足形式关闭限制。第二,可接受的夹具设计类被评估在几个标准然后选择最理想的夹具设计。在这工作中是地方化准确性、和定位器是被考虑成工作指标的准则和效率。这些标准包括在一个夹具设计中的关键错误来源、位置误差和不需要的压力在部份夹具原理，这种原理是由一个被超载的或被失衡的力量系统决定的。优选的夹具的设计方法是建立在最宜的实验设计的概念的基础上的。被开发算法高效率地利用递归物产在定位和力量分析评估可接受的设计。算法产生符合一套多个性能要求的优选的夹具设计。2多目标夹具定位器优化在许多应用上夹板已经是固定的被给予一些实用考虑过。然后如果钳位被预定义,最佳的夹具涉及某一表现标准由选择适当的套定位器,这样明显作用的重大改善被认可。使用任意互换算法我们分析夹具表面最佳的压力，这样我们能选择最佳的夹具设计方案标准。通过在几个零件中使用分析任意互换算法的作用,可以使用以下统计和经验的观察。3优选夹具夹紧这个部分应付一个更加复杂的问题同时为了达到夹具质量必需寻找最佳的钳位和定位器。一旦变化钳位，组合的数量为可能的钳位定位器的选择将会明显的增多。很明显为精确定位目标这个问题是易