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本科生毕业设计（论文）I摘要在化工生产中，分馏塔承受筒体内压、自重、风载荷和地震载荷的作用容易产生载荷振动和诱导振动。当振动频率接近于塔的自振频率时，塔就会发生共振、可能导致设备的破坏。因此，如何减小塔设备受风力作用而产生的诱导振动造成严重的危害，提高塔设备的抗振能力都是需要在设计时予以考虑的问题。本论文的题目是“基于ANSYS的柴油分馏塔的固有频率的计算”。本文以柴油分馏塔为研究对象，应用ANSYS有限元软件对设备进行了固有频率的计算，首先采用SHELL63单元建立分馏塔的三维实体模型，然后用自由分网的方法对其进行网格划分，施加约束和载荷，最后应用模态分析功能求解出柴油分馏塔的固有频率和振型。然后利用集中质量法假设把均布质量作为一个与之相当的集中质量放置在塔的顶端，根据动能平衡的原理以及虚梁法可以确定不等截面悬臂梁式柴油分馏塔自振周期。这一结果表明基于ANSYS的有限元法对柴油分馏塔自振周期的计算准确性高，计算方便，为工程上其他复杂模型固有频率的计算提供了方法依据。关键词：ANSYS；柴油分馏塔；固有频率；振型本科生毕业设计（论文）IIAbstractInchemicalproduction,fractionationtowerwerepronetovibrationandinducedvibrationloadsbeacauseofwithstandingthebodycylinderpressure,deadweight,windloadsandseismicloads.Whenthevibrationfrequencyclosetothetowernaturalfrequency,thetowerresonanceoccurs,whichmayresultinequipmentdamage.Therefore,howtoreducethedamageduetowind-inducedvibrationeffecttoimprovethetower'svibrationcapabilitiesarerequiredtobeconsideredinthedesign.ThethesisiscalculationsofdieseldistillationtowernaturalfrequencyonANSYS,andmainlystudyforthedieseldistillationcolumn.First,IapplySHELL63elementinfiniteelementsoftwareANSYStoestablishthree-dimensionalsolidmodelofdistillationtower,andthentomeshandimposeconstraintsandloading,modalanalysis,andfinallysolvethedieseldistillationtowernaturalfrequenciesandmodeshapes.Thenassumetheuniformqualityasanequivalentconcentratedmassplacedinthetower'stopbasedonLumpedmassmethod,anddeterminethenaturalcycleofdieselfractionatoraccordingtotheprincipleofkineticenergybalanceaswellasvirtualcantileverbeammethod.TheresultsshowthatieselfueldistillationcolumncalculationofthenaturalcyclebasedontheANSYSfiniteelementmethodisofhighaccuracy,easytocalculate,providindamethodofcalculatingthenaturalfrequencyfortheothercomplexmodels.Keywords：ANSYS；Dieselfractionatortower；Naturalfrequencyofvibration；Vibrationmodel本科生毕业设计（论文）III目录第1章绪论.......................................................................................................11.1本课题的研究背景及意义.....................................................................11.2ANSYS软件主要功能............................................................................11.3ANSYS软件简介....................................................................................21.3.1ANSYS的使用环境.....................................................................21.3.2有限元方法简介..........................................................................31.4分馏塔的简介.........................................................................................41.4.1分馏塔的特点..............................................................................41.4.2分馏塔的工作过程......................................................................41.4.3分馏塔分析计算的条件...............................................................5第2章分馏塔实体模型的建立..........................................................................62.1实体造型简介.........................................................................................62.2ANSYS的坐标系....................................................................................62.3建模的原则............................................................................................82.4建模的步骤............................................................................................82.4.1环境设置......................................................................................82.4.2初始化设计变量..........................................................................92.4.3定义单元类型..............................................................................92.4.4定义材料属性：..........................................................................92.4.5定义实常数................................................................................112.4.6创建塔的几何模型....................................................................112.5命令流分析过程...................................................................................14第3章有限元模型的建立................................................................................173.1基础知识..............................................................................................173.1.1网格类型....................................................................................173.1.2选择实体....................................................................................183.2划分网格..............................................................................................19第4章模态分析...............................................................................................224.1模态分析..............................................................................................224.2模态提取法..........................................................................................22本科生毕业设计（论文）IV4.3施加约束..............................................................................................254.4施加载荷..............................................................................................264.5求解......................................................................................................284.6扩展模态...............................................