(硕士气动热环境研究)气动加热环境下结构动态特性及动响应分析

硕士学位论文气动加热环境下结构动态特性及动响应分析ANALYSISOFDYNAMICCHARACTERISTICSANDRESPONSEUNDERTHEAERO-THERMALENVIRONMENT张晓蕾哈尔滨工业大学2011年6月国内图书分类号：TM631+.2学校代码：10213国际图书分类号：621.3密级：公开工学硕士学位论文气动加热环境下结构动态特性及动响应分析硕士研究生：张晓蕾导师：于开平教授申请学位：工学硕士学科、专业：一般力学与力学基础所在单位：航天学院航天工程与力学系答辩日期：2011年6月24日授予学位单位：哈尔滨工业大学ClassifiedIndex：TM631+.2U.D.C.：621.3DissertationfortheMasterDegreeinEngineeringANALYSISOFDYNAMICCHARACTERISTICSANDRESPONSEUNDERTHEAERO-THERMALENVIRONMENTCandidate：ZhangXiaoleiSupervisor：Prof.YuKaipingAcademicDegreeAppliedfor：MasterofEngineeringSpeciality：GeneralMechanicsandFoundationofMechanicsAffiliation：DepartmentofAerospaceEngineeringandMechanics,SchoolofAstronauticsDateofDefence：June,24th,2011Degree-Conferring-Institution：HarbinInstituteofTechnology哈尔滨工业大学硕士学位论文摘要本文主要对高速飞行器结构在气动加热环境下的动态特性及动响应进行了研究。随着高超声速飞行器技术的发展，飞行任务的气动热环境更加恶劣，飞行器结构受热环境的影响也越来越大。因此对结构热环境下动态特性的研究也日益迫切。首先，文章介绍了梁板结构关于热-结构非耦合振动的理论，并给出了解析解的求解过程。在此基础上推导了一种求解存在热应力情况下结构附加刚度矩阵的求法。基于此，结构热环境下的动响应问题得以用有限元方法求解。通过对梁结构热振动理论解的扩展，得出用有限元方法求解结构热振动问题必须采用体单元。其次，将用温度梯度引起的热应力作为预载荷求解结构刚度矩阵，及用非线性求解方法将整个过程分为多个载荷增量步，再基于每步多次迭代求解结构热问题两种方法应用到相同的结构中，分别得出两者的优缺点。另外，文中对典型TPS结构在热环境下进行了随机响应分析。最后，本文对复杂结构模型简化及有限元建模的难点提出了一些解决办法：适当的建立壳单元，并用RSSCONSurf-Vol来连接两种不同类型的单元；固体火箭发动机药柱的建模可以采用轴线上多个集中质量进行简化，并用一个RBE2单元及多个RBE3单元将这些集中质量按权值分配到发动机壳体上。文中对结构在气动热环境下动态特性及动响应的研究将对实际工程工作有一定的指导意义。关键词：动态特性，温度梯度，气动热环境，有限元-I-哈尔滨工业大学硕士学位论文AbstractThispapermainlyresearchesondynamiccharacteristicsandresponseofhigh-speedspacecraftstructuresunderaero-thermalenvironment.Withthedevelopmentofhypersonictechnologyandthedeteriorationofthetaskenvironment,theinfluenceofthermalenvironmentonthespacecraftstructuresbecomesmoreandmoresignificant.Thusitisbadlynecessarytostudyonthedynamiccharacteristicsofstructuresunderthermalenvironment.Firstly,thetheoryofthermal-structuraluncoupledvibrationofbeamsorplatesisintroduced,andtheprocessofobtainingtheanalyticalsolutionisgiveninthispaper.Thenamethodtogettheadditionalstiffnessmatrixofastructure,withinthecircumstancesofthermalstressisderived,basedonwhichthedynamicproblemscanberesolvedbyfiniteelementmethod(FEM).Accordingtotheextensionoftheanalyticalsolutions,solidelementshouldbeadoptedwhenusingFEMtoresolvethermalvibrationproblems.Secondly,twomethodsareusedtoanalyzethesamestructure.Oneistogetthestructuralstiffnessmatrix,treatingthethermalstressduetoatemperaturegradientasapre-load.Theotherisanonlinearmethod,inwhichthewholeprocessisseparatedintoseveralloadincrementalstepsandmulti-iterationisappliedforeachstep.Theadvantagesanddisadvantagesofboththetwomethodscanbeseeneasilythroughthisprocess.Inaddition,therandomproblemofakindoftypicalTPS(ThermalProtectionSystem)platesisanalyzed.Finally,severalmethodsofsimplifyingandmodelingaregiven.SuchascreatingshellelementsproperlyandconnectingtheseshellelementstosolidelementswithRSSCONSurf-Volelements,buildingcertainnumbersoflumpedmasselements,whichshouldbeconnectedtotheshelloftheenginewithaRBE2elementandseveralRBE3elements,asthesimplificationofthesolidpropellantgrain.Theworksabouttheanalysisofdynamiccharacteristicsandresponseofhigh-speedspacecraftstructuresunderaero-thermalenvironmentinthispapercanbeimportantforpracticalapplications.Keywords:dynamiccharacteristics,temperaturegradient,aero-thermalenvironment,finiteelementmethod(FEM)-II-哈尔滨工业大学硕士学位论文目录摘要.........................................................................................................................IABSTRACT...................................................................................................................II第1章绪论.............................................................................................................11.1课题来源....................................................................................................................................11.2课题背景....................................................................................................................................11.3国内外研究现状及进展............................................................................................................21.3.1热环境下的结构温度分布计算........................................................................................31.3.2热环境下飞行器结构振动特性问题................................................................................41.3.3热防护系统........................................................................................................................51.4研究内容....................................................................................................................................71.5本章小结....................................................................................................................................7第2章热环境下结构振动计算基本理论.................................................................82.1梁的热振动................................................................................................................................82.2板的热振动..............................................................................................................................112.3结构热振动计算刚度矩阵的形成.......