螺栓预紧结构用Hypermesh做接触实例

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如何在hypermesh中连接柔性单元(二保焊螺栓)如何在hypermesh中实现柔性体-柔性体的连接(二保焊、螺栓)

【包子原创教程】如何在hypermesh中连接柔性单元（二保焊螺栓）如何在hypermesh中实现柔性体-柔性体的连接（二保焊/焊缝、螺栓）教程简介：hypermesh（dyna模块）的柔性单元之间的连接一般用来模拟二保焊/焊缝和螺栓连接，本教程将详细向你介绍如何如何实现这种连接。

二保焊（焊缝）、螺栓连接，一般通过刚性单元rigid模拟，和柔性单元连接。

注意：rigid 单元card image=none，没有材料和属性。

进入rigid面板（1-2）。

点击节点创建rigid单元（3-5）。

2 焊点，通过spot连接，连接柔性单元。

进入spot面板（1-3）。

单击nodes（5），选择焊点所在节点（6-7），一般模型中会给出焊点的位置数据，比如用小球表示。

选择焊点连接的部件（8-9），连接部件的类型（10）选择elems，根据实际情况选择层数，图中total 2表示二层焊（11）。

容差要大于部件之间的距离（12）。

材料类型选择mat100（hexa）（13），输入焊点直径（14）。

焊点单元绿色表示成功，黄色表示失效，红色表示创建失败。

创建焊点材料。

注意，一般不使用自动生成的材料、属性和接触，删除之后重新创建。

创建材料，选择100号材料（15-16），编辑材料参数（17）。

输入材料参数（18-19）。

创建材料属性，选择实体单元（因为焊点是实体）（20-23）。

给焊点单元赋予材料和属性。

创建焊点和部件之间的接触。

进入接触面板（24-25）。

创建接触（26-27），type选择ContactSportweld（28），进入编辑面板（29）。

输入参数，静摩擦因数（FS）和动摩擦因数（FD）（30-31）。

添加主部件，选择被焊点连接的部件（33-34）。

添加从部件，选择焊点单元（35-36）。

单击review检查接触是否正确（38），蓝色显示的是主部件，红色显示的是从部件（38）。

螺栓预紧结构用Hypermesh做接触实例

在很多场合，要将若干个零件组装起来进行有限元分析，如将连杆与连杆盖用连杆螺栓连接起来，机体与气缸盖用螺栓连接起来，机体与主轴承盖连接起来。

如何模拟螺栓预紧结构更符合实际情况，是提高有限元计算精度的关键。

螺栓+螺母的连接与螺钉的连接有所不同，螺栓+螺母的连接方式比较简单，可以假设螺母与螺栓刚性连接，由作用在螺母上的拧紧力矩折算出作用在螺栓上的拉伸力F ，将螺杆中间截断，在断面各单元的节点上施加预紧单元PRETS179，模拟螺栓的连接情况。

对于螺钉（双头螺栓）连接有些不一样，螺钉头部对连接件1施加压应力，接触面是一个圆环面，但栽丝的一端，连接件2受拉应力。

一种方法是在螺纹圆周上施加拉力，相当于螺纹牙齿接触部分，而且主要在前几牙上存在拉力，如第一牙承担60~65%的载荷，第二牙承担20~25%的载荷，其余作用在后几牙，但因螺纹的螺距较小，一般为1.5~2mm ，而单元的尺寸为3~4mm ，因此可以假定在连接件2的表面的螺纹圆周节点上施加拉力。

另一种方法是在连接件2的表面的整个螺纹截面的所有节点上施加拉力，这样可能防止圆周上各节点上应力过大，与实际情况差别较大，应为实际表面圆周各节点只承受60~65%的载荷。

比较好的处理办法是在连接件的表面单元的圆周节点上施加70%的载荷，在第二层单元的圆周节点上施加30%的载荷，但操作比较麻烦。

随着连接件1、2的内部结构和刚度不同，以及连接螺钉的个数和分布的不均匀性，连接件1、2表面的变形不一致，产生翘曲，使表面的节点有的接触，有的分离，而导致接触面的应力分布和应变分布不均匀，因此需用非线性的接触理论来讨论合件的应力问题。

若不考察螺栓头部与连接件1表面的变形，可用将螺栓与连接件1用一个公共面连接，作为由两种不同材料的构件组成一个整体。

螺钉（双头螺栓）与连接件2也用这种方法处理。

图1是一个简单的螺钉连接实体模型。

图2是用hypermesh 划分网格后的模型。

图1 实体模型图2 网格模型该模型由三个零件组成，连接件1（蓝色）、连接件2（橙色），螺钉（紫红）。

螺栓螺纹三维接触有限元分析

机械 2010年第5期总第37卷计算机应用技术・31・———————————————收稿日期：2009－12－06作者简介：李波（1981－），湖北武汉人，硕士研究生，主要研究方向为机械结构分析。

螺栓螺纹三维接触有限元分析李波（华中科技大学机械科学与工程学院，湖北武汉 430074）摘要：在对螺栓螺纹的分析中，一般采用的方法是将螺栓简化为轴对称，建立轴对称有限元模型进行分析，即使是建立三维模型也是忽略了螺纹部分对整个有限元模型分析的影响。

在一些特殊的分析情况下，这样会大大降低分析的精度。

比如，在对螺栓螺纹防松机理方面的研究中，就必须考虑螺纹部分及其接触对整个分析过程的影响，而采用单一的有限元软件又很难完成。

正是基于这一原因，根据UG 、HyperMesh 和ANSYS 软件的特点，综合运用其长处可以完成螺栓螺纹从几何建模、网格划分、分析计算到结果处理的整个过程．实例表明，综合运用各种软件，有利于发挥每种软件的优点，大大提高有限元分析的效率。

关键词：螺栓螺纹；UG ；HyperMesh ；ANSYS ；三维接触中图分类号：TH131.3 文献标识码：A 文章编号：1006－0316 (2010) 05－0031－03Three-dimensional contact ofthreaded bolt finite element analysisLI Bo(Mechanical Engineering College ，Huazhong University of Science and Technology ，Wuhan 430074，China) Abstract ：Generally, we using axis symmetry in the screw thread of bolt finite element analyse. Even though, neglecting the effect of screw thread to the whole three-dimensional finite element model. Reducing precision in some special occasion. For instance ,in research of preventing screw thread of bolt from loosening, it must take into account of the compact of the screw thread and the contact. But it hard to accomplish the mission in using single software. With the issues that finite element analysis using single software is complicated and low efficient ，the UG ，HyperMesh and ANSYS softwares are synthetically applied in the course of modeling ，plotting finite element grids ，calculating and analyzing ，and result dealing based on their respective characteristic ．The example indicates that the comprehensive application of various finite element softwares can exert their corresponding advantages and make the analysis more efficient ．Key words ：threaded bolt ；UG ；HyperMesh ；ANSYS ；three-dimensional contact有限元法是随着计算机的发展而迅速发展起来的一种现代计算方法。

Hypermesh 2017or2019_新建接触步骤

图 6 新建目标面单元类型
新建目标面单元类型，设置如图 6 所示。（根据实际实际情况设置关键字，图中仅为示例）
图 7 新建接触面单元类型新建接触面单元类型，设置如图 7 所示。（根据实际实际情况设置关键字，图中仅为示例）
4. 新建接触面（Contact Surface）
新建并选中接触面，点击“Elements”，如图 8，按照图 9 第三步选择吊带（红色组件）的单元，第四步选择法向面节点（选择的节点尽量多一点），如图 10。新建的接触面即图 11 中的青色部分。
图 13
图 14
图 15
图 16
图 17 在标签区选中新建的接触组，进行如图 18、图 19、图 20、图 21 和图 22 的设置，到这就完成了在 Hypermesh 2017/2019 中新建接触的所有步骤。
图 18 图 19
图 20 图 21
图 22
Hypermesh 2017/2019 新建接触步骤
1. 新建材料
图1 图2
图3 根据图 1、图 2 和图 3 新建材料。
2. 新建目标面属性（Propertity）
图 4 新建目标面属性
图 5 设置实常数按图 4 所示新建目标面属性，实常数保持）
图8 图8
图 9 选择接触面单元图 10 选择法向面的节点
图 11 吊带的接触面按照上述步骤新建安全座的接触面，如图 12 所示。
图 12 安全座的接触面
5. 新建接触组（Group）
按图 13 方式从主菜单中进入 interfaces 界面，并按照图 14 创建接触组,并根据图 15、图 16 和图 17 进行操作，主面（master）对应的是接触面，从面（slave）对应目标面。

hyperworks接触分析

好问题，学习了
报告道具 TOP 8#
/viewthread.php?tid=932569&highlight=contactsurf 2011-5-7
hypermesh中定义接触contact的问题 - CA01：HyperMesh&HyperView--前后... 页码，6/8
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误
CONTACT interface
1 has Slave
node 900 that lies exactly on the
Master surface with OPENGAP option. Impossible to define pushout
direction.
请教下我少做了哪个步骤..谢
谢.
/viewthread.php?tid=932569&highlight=contactsurf 2011-5-7
hypermesh中定义接触contact的问题 - CA01：HyperMesh&HyperView--前后... 页码，2/8

hypermesh中定义接触contact的问题 - CA01：HyperMesh&HyperView--前后... 页码，4/8

hyperworks接触分析实例教程1

hyperworks接触分析实例教程1Pre-Processing for Pipes Impact using RADIOSS Block - RD-3520For this tutorial it is recommended that you complete the introductory tutorial, Getting Started with HyperMesh - HM-1000. Working knowledge of the creation and editing of collectors and card images are a definite pre-requisite. Familiarity with the interfaces panel, and the creation of boundary conditions are useful, although not required.ObjectiveIn this tutorial you will learn how to set up a RADIOSS input file in HyperMesh for analyzing the impact response between two pipes. The modeling steps that are covered are:Model DescriptionThe units used in this tutorial are milliseconds, millimeters and kilograms (ms, mm, kg), and the tutorial is based on RADIOSS Block 51.Pipe model ExerciseStep 1: Load the RADIOSS Block User Profile and import the modelIn the following steps, load the RADIOSS Block User Profile, then import a RADIOSS input deck containing the mesh for the two pipes.Selecting the RADIOSS User Profile sets the FE input reader to RADIOSS Block and loads theRADIOSS51 FE output template. It also loads a RADIOSS macro menu with numerous tools specific to this interface. The graphical user interface is tailored to RADIOSS users with panels such as the admas panel on the 1D page, panel names and options renamed or removed to match RADIOSS terminology.The model is loaded and is organized into two component collectors: 1 and 2 (named by HyperMesh). No materials or properties are defined at this time.Creating materials, sections, and parts for the model.?Defining the contact between the two pipes using /INTER/TYPE7.?Applying a translational initial velocity to a pipe using the /INIVEL card.?Applying local constraints to the other pipe using the /BCS card.1.Load the Radioss Block User Profile using the pull down menu Preferences > User Profile > RADIOSS(Block Format) > BLOCK90 ....2.From the files panel, select the import subpanel and import the following RADIOSS deck:/tutorials/hwsolvers/radioss/pipesd00.Notes:On import of a RADIOSS deck, any HyperMesh warning and error messages are written to a fileOn import, any RADIOSS cards not supported by HyperMesh are written to the control cardunsupp_cards . This card is accessed from the control cards panel on the BCs page and is apop-up text editor. The unsupported cards are exported with the rest of the model.Care should be taken if an unsupported card points to an entity in HyperMesh. An example of this is an unsupported material referenced by a /PART card. HyperMesh stores unsupported cards as text and does not consider pointers.On import, HyperMesh renumbers entities having the same ID as other entities. In HyperMesh, for example, all elements must have a unique ID. The message file radiossblk.msg provides a list of renumbered elements and their original and new IDs.Step 2: Understand the relationships between the /PART, /SHELL, /MAT and /PROP cards in HyperMeshA /PART shares attributes such as section properties (/PROP) and a material model (/MAT). A group of shells (/SHELL) sharing common attributes generally share a common part ID (PID).The figure below shows how these keywords are mapped to HyperMesh entities:Map to HyperMesh entities Component, property and material collectors are created and edited from the collectors panel.For the RADIOSS keyword interface, there is only one component card image and it is named Part . There are several property card images, such as P1_shell P2_truss , P14_solid . There are many material card images, such as M1_ELAST , M48_HONEYCOMB .The complete list of card images is available from the collectors panel, as you assign card images to the various types of collectors.A HyperMesh card image allows you to view the image of keywords and data lines for defined RADIOSS entities as interpreted by the loaded template. The keywords and data lines appear in the exported RADIOSS input file as you see them in the card images. Additionally, for some card images, you can define and edit various parameters and data items for the corresponding RADIOSS Block.Use the card (card editor) panel from the permanent menu to review and edit card images. Also, for many entities, their card image can be viewed and edited from the panels in which they are created.Step 3: Create a /MAT card In HyperMesh, a /MAT card is associated to a material collector. To relate it to a /PART card, the material collector needs to be assigned to a component collector.You can assign the material to the component collector as you create the component using the createsubpanel of the collectors panel. In situations where the material was not assigned to the component at the time of creation (and in this case, a dummy material is created with the same name as the componentnamed radiossblk.msg . This file is created in the folder from which HyperMesh is started. The content of the file is also displayed in a pop-up window./SHELL elem_ID part_ID> Organized into component collectors/PART part_ID prop_ID mat_ID > Component collector with a componentcard image/PROP prop_ID > Property collector with a property cardimage/MAT mat_ID>Material collector with a material cardimagecollector), update the component collector's definition by assigning the material in the update subpanel of the collectors panel.In this step, create a material collector with the M1_ELAST card image using the collectors panel. This material will be assigned to both pipes.1.Create/edit a material collector with the name elast1, and a M1_ELAST card image using the createsubpanel of the collectors panel.2.In the card previewer, click [Rho_I] to activate its field.For density, specify 7.8 E-6For Young's modulus [E], specify 208For Poisson's ratio [nu], specify 0.30Note:If you have difficulties completing any task with the creation, update or editing of collectors in this tutorial, refer to the on-line help for the collectors panel by clicking help from the permanent menu. Hint:Any collector that you mistakenly create instead of create/edit can be edited using the card image subpanel of the collectors panel.In this step, we created the material we will use for the analysis. We can now define the /PROP card that will be used to define the properties of the elements in the model.Step 4: Create a /PROP cardIn HyperMesh, the /PROP card is assigned to a property collector. To generate this card, create a property collector using either Property collector icon in the toolbar or from the pull down menu Properties > Create. The model consists of two pipes modeled with shell elements. Create a property collector witha /PROP/SHELL card that will be used for all the elements.1.Create a property collector with the name prop shell, set Type = to surface, set card image= toP1_SHELL, and Thickness = 2.5 card.2.In the card previewer for the /PROP/SHELL card, check 2.5for the shell thickness [Thick].Step 5: Assign the /PART, /MAT and /PROP cards to the elementsAssign the /PART card to the component for the coarse pipe and specify the /PROP/SHELL card ID in it.1.Load the Component Collector Update panel from either the toolbar Component collector or from thepull down menu, select Component > Create.2.Click update subpanel.3.Select the pipe 1 component.4.For card image, select PART.5.Assign the material elast1 and property prop shell.6.Click update.Repeat this procedure for pipe 2.Step 6: Create contact cardsRADIOSS contacts are created in the interfaces panel from the Analysis page or from the pull down menu, selectBCs>Create>Interfaces.A RADIOSS contact is a HyperMesh group. When you want to manipulate an /INTER card, such as delete it, renumber it, or turn it off, you need to work with HyperMesh group entities.In this step, create a contact between the two pipes using /INTER/TYPE7. The pipe with the coarser mesh (2) will be the master surface while the one with finer mesh (1) will be the slave surface. RADIOSS has multiple ways to define master andslave entity types from which to choose; in this example define the master and slave entities as components, doing this the master will be exported as /SURF/PART and the slave asa /GRNOD/PART.First create a group interface with the TYPE7card image using the create subpanel of the interfaces panel.Next, add the master and slave to the group using the add subpanel. Lastly, edit the group’s card image using the card image subpanel, and specify a friction coefficient.Automatically TYPE7 is selected for card image.In this step, we defined the contact between the two pipes as /INTER/TYPE7.Creating boundary conditions for a deck in RADIOSS Block can be efficiently carried out with the BC’s Manager available on the Utility Browser , which can be switched on the screen from the View pull down menu.Every load needs to be stored in a load collector with the corresponding card image. For example, store the velocity loads ina velocity load collector and boundary conditions in the respective collector.1.Create a group with the name contact and the TYPE7 card image using the create subpanel of the interfaces panel.2.From the BCs page, select the interfaces panel or from the pull down menu, select BCs > Create > Interfaces .3.Select the create subpanel.4.In the name= field, enter contact .5.For type=, select TYPE7.6.Optionally select a color.7.Click create .8.From the interfaces panel, select the add subpanel.9.Under master , set the entity type to comps :10.Click the yellow comps selector and select the coarser pipe component 2.11.Click update in the master: field, to the right of the yellow comps selector.12.For slave:, select comps .13.Click the yellow comps selector in the slave:line and select the finer mesh pipe component 1.14.In the slave: field, click update .15.Click review to graphically view the entities in the interface, the master entities of the interface are drawn in blue and the slave entities in red.16.Edit the definition of the group, using the card image subpanel to set the static coefficient to 0.10.17.From the interfaces panel, select the card image subpanel.18.Click edit to review the card image.19.Specify 0.10 for the static coefficient [FRIC].Step 7: Create an initial velocity (/INIVEL/TRA)In this step, we will apply a translational initial velocity to the coarse pipe using /INIVEL/TRA applied to a predefined set of nodes /GRNOD/PART.1.Click on BC’s Manager on the Utility browser.2.From the Boundary Conditions Manager, enter the name tran_vel and select the type as initialvelocity under the Create header.3.For creating a entity set of type GRNOD which is referred to in the INIVEL card, click on Parts button andselect the coarser pipe from the GUI (component ID 2). Click proceed.4.In the BC’s Manager, enter the initial velocity components as 0,0 and -30 for Vx, Vy and Vz fields.5.There is an option for creating/referring the initial velocity card to a local coordinate system. However ifnothing is specified, the global coordinate system is selected by default.6.There is an option to specify the size of the load display on the screen under Label Scale.7.Click the create button. Double check in the model browser for your reference that a load collector andan entity set is created.This completes the creation of an initial velocity for the pipe in the negative global Z direction.Step 8: Create a /BCS and constrain the finer mesh pipeIn this step, we will fully constrain the end nodes of the bottom pipe by using the Boundary Conditions Manager.1.In the BCs Manager under the Create subheading, enter the Name SPC and set Select type asBoundary Condition.2.Now specify the node set of type as GRNOD for the BCS card, switch the entity from parts to Nodesand select the end nodes of the bottom pipe, which are to be constrained.3.Under the Boundary condition components subheading (as illustrated below) activate all thetranslational and rotational check boxes. Click the create button. A load collector with a BCS card is Step 9: Create output definitions and control cardsA window pops up.created and applied the nodes as selected in the above steps. A corresponding node set is created.1.In the Utility menu of the solver browser, click the Engine button.2.Select the options, as shown below.Step 10: Export the modelThis concludes this tutorial. You may discard this HyperMesh model or save it for your own reference. In this tutorial we introduced some of the concepts that govern the HyperMesh interface to RADIOSS. We also use numerous panels that allowed us to do basic modeling in terms of RADIOSS such as defining contacts or boundary conditions.EXERCISE EXPECTED RESULTS3.Click Apply and Close to store the selected options for control and output.1.On Standard toolbar at the top of the HyperMesh window, click Export.2.For File:, click the foldericon and navigate to destination directory where you want to run.3.For Name , enter pipeimpact and click Save .4.Click the downward-pointing arrows next to Export options to expand the panel.5.Click Auto export engine file to export the engine file with the model file.6.Click Export to export both model and engine file.Final deformation and energy balance plotSee alsoSee HyperMesh Tutorials for a complete list of tutorials.。

关于hypermesh中做接触需要注意的一些问题

关于HYPERMESH中做接触需要注意的一些问题研究了两天，终于大概搞出个所以然来。

在Hypermesh中做接触分析，要区分两种状态：1接触体（GA）与目标体(GB)的距离如果小于1e-14，那就需要定义一个局部坐标系，坐标系的X轴是GA->GB的方向。

如果是圆周接触，那就需要定义一个柱坐标系，X轴是径向方向。

1.1在gap单元的property（PGAP）中，U0=AUTO，KA=auto，KB=blank，MU1=blank,MU2=blank。

1.2在control card的GAPPRM中，CKGPDIR=REV(因为距离非常近，有可能GA已经渗透入GB，此时X方向就不能代表GA->GB。

REV选项可以调整这种反向的状态)，GAPGPRJ=NORM，ERRMSG=FULL（输入所有错误信息，可以看出哪里出了问题）。

2GA与GB距离大于1e-14，无需定义局部坐标系。

2.1在gap单元的property（PGAP）中，U0=AUTO，KA=auto，KB=10（一个小一些的值），MU1=blank,MU2=blank。

或U0=0，KA=auto,KB=blank。

2.2在control card的GAPPRM中，CKGPDIR=ERR，GAPGPRJ=NORM，ERRMSG=FULL对于PGAP一些参数的解释：如果要设置非滑移表面，则可以在control card中，设置PARAM,GAPOFFSET = NO。

下面是余秋雨经典励志语录，欢迎阅读。

不需要的朋友可以编辑删除！！关于年龄1.一个横贯终生的品德基本上都是在青年时代形成的，可惜在那个至关重要的时代，青年人受到的正面的鼓动永远是为成功而搏斗，而一般所谓的成功总是带有排他性、自私性的印记。

结果，脸颊上还没有皱纹的他们，却在品德上挖下了一个个看不见的黑洞。

2.我不赞成太多地歌颂青年，而坚持认为那是一个充满陷阱的年代。

陷阱一生都会遇到，但青年时代的陷阱最多、最大、最险。

Ansys workbench 螺栓接触实例操作

8例1 螺栓连接件分析如图所示为一螺栓连接的法兰连接件简图，法兰一端及内侧面固定约束。

载荷1为螺栓预应力1000N载荷2为螺栓预应力1500N载荷3为螺栓预应力2000N根据实际情况，自己设定接触类型，其中摩擦类型接触对时，摩擦系数为0.1 为方便设置，材料均取钢材，求其变形及应力。

边界条件螺栓连接件分析1 导入几何模型，进入DS模块2 材料设置选择默认的材料：Structural Steel3 设置接触螺栓与螺母的接触类型为Bonded螺栓杆与法兰的接触类型为Frictional，摩擦系数为0.1螺栓杆与垫片内壁的接触类型为Frictional，摩擦系数为0.1其余接触类型为No Separation4 网格划分5 选择分析类型·在“New Analysis”中选择结构静力学分析“Static Structural”；6 施加约束与载荷1）施加固定约束·点击“Static Structural”，在“Supports”中选择固定约束“Fixed Support”·选择法兰一端及内侧面固定约束；2）施加载荷·选择载荷1处螺栓杆表面，添加螺栓预应力“Bolt Pretension”大小为1000N ·选择载荷2处螺栓杆表面，添加螺栓预应力“Bolt Pretension”大小为1500N ·选择载荷3处螺栓杆表面，添加螺栓预应力“Bolt Pretension”大小为2000N5 设定求解类型1）求解变形·点击“solution”，点击“Deformation”选择“Total”，求解变形·点击“Stress”，选择“Equivalent (V on-Mises)”，求解等效应力6 单击“Solve”求解7 观察求解结果·点击“Total Deformation”查看变形·点击“Equivalent Stress”查看应力分布例2卡紧散热片的不锈钢扣件受力分析扣紧件是一个不锈钢的卡子，因为散热片同功率部件之间的接触力同最终的散热有很大关系，因此研究力的大小是很有意义的。

hypermesh螺栓连接类型

hypermesh螺栓连接类型
在有限元分析领域中，螺栓连接是一种经常用到的连接形式，它在模型的刚度分析中扮演着关键的角色。

在Hypermesh中，也提供了多种螺栓连接类型来满足用户的设计需求。

本文将对Hypermesh螺栓连接类型进行简单介绍，并分为以下几个方面：
1.孔配准型（Mesh to Node）
这种类型的连接方法可以将单元的网格和节点连接到另一个部件的节点上，通过这种方式实现两个部件的配合效果。

比如，在一些接触问题中，可以使用这种类型的连接方法来模拟金属部件与垫片的连接效果。

孔配准型连接还可以应用于连接螺栓或销钉等细长的零件。

2.面配准型（Mesh to Mesh）
面配准型连接相比孔配准型，更适用于连接面之间的部件。

它可以将两个或多个面之间的网格进行连接，实现高强度连接，广泛应用于连接机器、设备、结构等领域。

3.轴向连接型（Axial）
轴向连接型是一种基于螺栓轴向负载的连接类型。

它可以让用户在有限元分析中快速进行多个螺栓的连接布置和参数计算，从而确保连接的高强度、高刚度和高可靠性。

常见的轴向连接类型包括双头螺栓和单头螺栓。

4.点焊连接型（Weld）
点焊连接型是一种基于点焊的连接类型。

在这种连接类型中，用户可以模拟点焊的强度和刚度，并在有限元分析中应用于模拟车身等结构的焊接连接。

总体来说，Hypermesh螺栓连接类型非常灵活，可以根据用户的具体设计需求，选择不同的连接类型，并进行灵活布局和参数调整。

通过对螺栓连接类型的深入了解和应用，用户可以更好地完成模型建立与分析，提高设计效率，优化设计方案，从而实现高质量的产品设计与开发。

ansys技巧总结_螺栓连接的模拟实现问题

ansys技巧总结_螺栓连接的模拟实现问题
刚做完钢结构节点有限元分析。

效果不错。

我的做法螺栓用psmesh施加预应力，
两块端板间采用接触技术。

螺栓连接的模拟实现问题，还是要看你想研究目的是什么。

如果研究节点的性能可以实体建模用premesh和接触分析，但很耗资源，因为包含接触非线性与材料非线性，我做过一颗螺栓的问题，大概五小时的时间，1G的结果文件。

如做框架分析就约束方程较为简单。

这个问题，我看大家都比较关心，的确这也是一个比较实际的问题
我的看法如下：
一，如果分析螺栓本身，那么用接触分析比较好，国内是实际例子也比较多，就是归于节点分析一类
二。

如果螺栓没有相对构件的平面位移，那么用预紧单元+粘结即可
三，也可以考虑在螺栓位置加较大数量级的对称压力
四，耦合，说白了，就是强制让相关节点的某些自由度一致。

hyperworks接触分析实例教程1

Pre-Processing for Pipes Impact using RADIOSS Block - RD-3520For this tutorial it is recommended that you complete the introductory tutorial, Getting Started with HyperMesh - HM-1000. Working knowledge of the creation and editing of collectors and card images are a definite pre-requisite. Familiarity with the interfaces panel, and the creation of boundary conditions are useful, although not required.ObjectiveIn this tutorial you will learn how to set up a RADIOSS input file in HyperMesh for analyzing the impact response between two pipes. The modeling steps that are covered are:Model DescriptionThe units used in this tutorial are milliseconds, millimeters and kilograms (ms, mm, kg), and the tutorial is based on RADIOSS Block 51.Pipe model ExerciseStep 1: Load the RADIOSS Block User Profile and import the modelIn the following steps, load the RADIOSS Block User Profile, then import a RADIOSS input deck containing the mesh for the two pipes.Selecting the RADIOSS User Profile sets the FE input reader to RADIOSS Block and loads theRADIOSS51 FE output template. It also loads a RADIOSS macro menu with numerous tools specific to this interface. The graphical user interface is tailored to RADIOSS users with panels such as the admas panel on the 1D page, panel names and options renamed or removed to match RADIOSS terminology.The model is loaded and is organized into two component collectors: 1 and 2 (named by HyperMesh). No materials or properties are defined at this time.•Creating materials, sections, and parts for the model.•Defining the contact between the two pipes using /INTER/TYPE7.•Applying a translational initial velocity to a pipe using the /INIVEL card.•Applying local constraints to the other pipe using the /BCS card.1.Load the Radioss Block User Profile using the pull down menu Preferences > User Profile > RADIOSS(Block Format) > BLOCK90 ....2.From the files panel, select the import subpanel and import the following RADIOSS deck:<install_directory>/tutorials/hwsolvers/radioss/pipesd00.Notes:On import of a RADIOSS deck, any HyperMesh warning and error messages are written to a fileOn import, any RADIOSS cards not supported by HyperMesh are written to the control cardunsupp_cards . This card is accessed from the control cards panel on the BCs page and is apop-up text editor. The unsupported cards are exported with the rest of the model.Care should be taken if an unsupported card points to an entity in HyperMesh. An example of this is an unsupported material referenced by a /PART card. HyperMesh stores unsupported cards as text and does not consider pointers.On import, HyperMesh renumbers entities having the same ID as other entities. In HyperMesh, for example, all elements must have a unique ID. The message file radiossblk.msg provides a list of renumbered elements and their original and new IDs.Step 2: Understand the relationships between the /PART, /SHELL, /MAT and /PROP cards in HyperMeshA /PART shares attributes such as section properties (/PROP) and a material model (/MAT). A group of shells (/SHELL) sharing common attributes generally share a common part ID (PID).The figure below shows how these keywords are mapped to HyperMesh entities:Map to HyperMesh entities Component, property and material collectors are created and edited from the collectors panel.For the RADIOSS keyword interface, there is only one component card image and it is named Part . There are several property card images, such as P1_shell P2_truss , P14_solid . There are many material card images, such as M1_ELAST , M48_HONEYCOMB .The complete list of card images is available from the collectors panel, as you assign card images to the various types of collectors.A HyperMesh card image allows you to view the image of keywords and data lines for defined RADIOSS entities as interpreted by the loaded template. The keywords and data lines appear in the exported RADIOSS input file as you see them in the card images. Additionally, for some card images, you can define and edit various parameters and data items for the corresponding RADIOSS Block.Use the card (card editor) panel from the permanent menu to review and edit card images. Also, for many entities, their card image can be viewed and edited from the panels in which they are created.Step 3: Create a /MAT card In HyperMesh, a /MAT card is associated to a material collector. To relate it to a /PART card, the material collector needs to be assigned to a component collector.You can assign the material to the component collector as you create the component using the createsubpanel of the collectors panel. In situations where the material was not assigned to the component at the time of creation (and in this case, a dummy material is created with the same name as the componentnamed radiossblk.msg . This file is created in the folder from which HyperMesh is started. The content of the file is also displayed in a pop-up window./SHELL elem_ID part_ID> Organized into component collectors/PART part_ID prop_ID mat_ID > Component collector with a componentcard image/PROP prop_ID > Property collector with a property cardimage/MAT mat_ID>Material collector with a material cardimagecollector), update the component collector's definition by assigning the material in the update subpanel of the collectors panel.In this step, create a material collector with the M1_ELAST card image using the collectors panel. This material will be assigned to both pipes.1.Create/edit a material collector with the name elast1, and a M1_ELAST card image using the createsubpanel of the collectors panel.2.In the card previewer, click [Rho_I] to activate its field.For density, specify 7.8 E-6For Young's modulus [E], specify 208For Poisson's ratio [nu], specify 0.30Note:If you have difficulties completing any task with the creation, update or editing of collectors in this tutorial, refer to the on-line help for the collectors panel by clicking help from the permanent menu. Hint:Any collector that you mistakenly create instead of create/edit can be edited using the card image subpanel of the collectors panel.In this step, we created the material we will use for the analysis. We can now define the /PROP card that will be used to define the properties of the elements in the model.Step 4: Create a /PROP cardIn HyperMesh, the /PROP card is assigned to a property collector. To generate this card, create a property collector using either Property collector icon in the toolbar or from the pull down menu Properties > Create. The model consists of two pipes modeled with shell elements. Create a property collector witha /PROP/SHELL card that will be used for all the elements.1.Create a property collector with the name prop shell, set Type = to surface, set card image= toP1_SHELL, and Thickness = 2.5 card.2.In the card previewer for the /PROP/SHELL card, check 2.5for the shell thickness [Thick].Step 5: Assign the /PART, /MAT and /PROP cards to the elementsAssign the /PART card to the component for the coarse pipe and specify the /PROP/SHELL card ID in it.1.Load the Component Collector Update panel from either the toolbar Component collector or from thepull down menu, select Component > Create.2.Click update subpanel.3.Select the pipe 1 component.4.For card image, select PART.5.Assign the material elast1 and property prop shell.6.Click update.Repeat this procedure for pipe 2.Step 6: Create contact cardsRADIOSS contacts are created in the interfaces panel from the Analysis page or from the pull down menu, select BCs>Create>Interfaces.A RADIOSS contact is a HyperMesh group. When you want to manipulate an /INTER card, such as delete it, renumber it, or turn it off, you need to work with HyperMesh group entities.In this step, create a contact between the two pipes using /INTER/TYPE7. The pipe with the coarser mesh (2) will be the master surface while the one with finer mesh (1) will be the slave surface. RADIOSS has multiple ways to define master and slave entity types from which to choose; in this example define the master and slave entities as components, doing this the master will be exported as /SURF/PART and the slave asa /GRNOD/PART.First create a group interface with the TYPE7card image using the create subpanel of the interfaces panel.Next, add the master and slave to the group using the add subpanel. Lastly, edit the group’s card image using the card image subpanel, and specify a friction coefficient.Automatically TYPE7 is selected for card image.In this step, we defined the contact between the two pipes as /INTER/TYPE7.Creating boundary conditions for a deck in RADIOSS Block can be efficiently carried out with the BC’s Manager available on the Utility Browser , which can be switched on the screen from the View pull down menu.Every load needs to be stored in a load collector with the corresponding card image. For example, store the velocity loads in a velocity load collector and boundary conditions in the respective collector.1.Create a group with the name contact and the TYPE7 card image using the create subpanel of the interfaces panel.2.From the BCs page, select the interfaces panel or from the pull down menu, select BCs > Create > Interfaces .3.Select the create subpanel.4.In the name= field, enter contact .5.For type=, select TYPE7.6.Optionally select a color.7.Click create .8.From the interfaces panel, select the add subpanel.9.Under master , set the entity type to comps :10.Click the yellow comps selector and select the coarser pipe component 2.11.Click update in the master: field, to the right of the yellow comps selector.12.For slave:, select comps .13.Click the yellow comps selector in the slave:line and select the finer mesh pipe component 1.14.In the slave: field, click update .15.Click review to graphically view the entities in the interface, the master entities of the interface are drawn in blue and the slave entities in red.16.Edit the definition of the group, using the card image subpanel to set the static coefficient to 0.10.17.From the interfaces panel, select the card image subpanel.18.Click edit to review the card image.19.Specify 0.10 for the static coefficient [FRIC].Step 7: Create an initial velocity (/INIVEL/TRA)In this step, we will apply a translational initial velocity to the coarse pipe using /INIVEL/TRA applied to a predefined set of nodes /GRNOD/PART.1.Click on BC’s Manager on the Utility browser.2.From the Boundary Conditions Manager, enter the name tran_vel and select the type as initialvelocity under the Create header.3.For creating a entity set of type GRNOD which is referred to in the INIVEL card, click on Parts button andselect the coarser pipe from the GUI (component ID 2). Click proceed.4.In the BC’s Manager, enter the initial velocity components as 0,0 and -30 for Vx, Vy and Vz fields.5.There is an option for creating/referring the initial velocity card to a local coordinate system. However ifnothing is specified, the global coordinate system is selected by default.6.There is an option to specify the size of the load display on the screen under Label Scale.7.Click the create button. Double check in the model browser for your reference that a load collector andan entity set is created.This completes the creation of an initial velocity for the pipe in the negative global Z direction.Step 8: Create a /BCS and constrain the finer mesh pipeIn this step, we will fully constrain the end nodes of the bottom pipe by using the Boundary Conditions Manager.1.In the BCs Manager under the Create subheading, enter the Name SPC and set Select type asBoundary Condition.2.Now specify the node set of type as GRNOD for the BCS card, switch the entity from parts to Nodesand select the end nodes of the bottom pipe, which are to be constrained.3.Under the Boundary condition components subheading (as illustrated below) activate all thetranslational and rotational check boxes. Click the create button. A load collector with a BCS card isStep 9: Create output definitions and control cardsA window pops up.created and applied the nodes as selected in the above steps. A corresponding node set is created.1.In the Utility menu of the solver browser, click the Engine button.2.Select the options, as shown below.Step 10: Export the modelThis concludes this tutorial. You may discard this HyperMesh model or save it for your own reference. In this tutorial we introduced some of the concepts that govern the HyperMesh interface to RADIOSS. We also use numerous panels that allowed us to do basic modeling in terms of RADIOSS such as defining contacts or boundary conditions.EXERCISE EXPECTED RESULTS3.Click Apply and Close to store the selected options for control and output.1.On Standard toolbar at the top of the HyperMesh window, click Export.2.For File:, click the foldericon and navigate to destination directory where you want to run.3.For Name , enter pipeimpact and click Save .4.Click the downward-pointing arrows next to Export options to expand the panel.5.Click Auto export engine file to export the engine file with the model file.6.Click Export to export both model and engine file.Final deformation and energy balance plotSee alsoSee HyperMesh Tutorials for a complete list of tutorials.。

预紧螺栓连接仿真分析

表 1 螺栓信息
螺栓牌号
公称直径 d （mm）
螺距 P（mm）
螺纹小径 d1 （mm）
M6
6
1
4.917
螺纹中径 d2 （mm）
5.350
螺旋副摩擦系数
f
0.15
螺母环形支承面外径 D0 （mm）
10
ቤተ መጻሕፍቲ ባይዱ
螺母环形支承面内径 d0 （mm）
6.2
螺母与支承面摩擦系数 fc
0.15
-93-
2018-13 (最终).indd 93
有限元模型建模及网格划分
典型对接中预紧螺栓受力情况。
螺栓连接件的典型截面连接型式如下，纵向含 3 个螺栓
预紧力计算
绝大多数螺栓连接在装配时都必须预紧，预紧的目的在
连接。其中：框 A、框 B 及螺栓均用实体单元 solid186 划分
于增强连接的可靠性和紧密性，以防止受载后被连接件间出
网格， solid186 选项参数 KP（2）=1，打开完全积分模式
约束及加载
截取部位端部的面法向的平动自由度约束，这部分通过在端面建局部坐标系实现；在框 B 连蒙皮的外突缘边缘 XYZ 三平动自由度约束；在框 A 外突缘边界建刚性区，载荷步 2 中对刚性区主节点加外载 F。如图 3 所示。
加载分两个载荷步：（1）对每个螺栓通过预紧单元加预紧力。（2）螺栓预紧后加外载 F（拉载 19545.4N）。
现缝隙或发生相对滑移。螺栓拧紧力矩与预紧力之间关系如
以适应实体复杂外型网格划分。螺栓完全用六面体网格划分，
下：
框绝大部分用六面体网格划分，在复杂 R 角过渡区，则采用
=T
F0 2
d2

预紧力作用下的螺栓联接板组装接触刚度分析

km E dA exp B d / L
（4）
式中 A 和 B 是与材料参数有关的常数；对于钢（ E 206.8GPa, 0.291 ）这个值为
A 0.78715 和 B 0.62873 。需要声明的是文献[16]和[11]中提供的刚度图是根据文献[16]
中的有限元结果而不是文献[4]中的曲线拟合。用指数函数来拟合曲线看上去是不合适的，当 d / L 变大时将完全失效。文献[6]提供了一个新的联接板刚度更容易的表达形式。文献[6]假设联接板上的应力可以表示为：
预紧力作用下的螺栓联接板组装接触刚度分析
Niels Leergaard Pedersen（副教授）,Pauli Pedersen（名誉教授，教授） (固体力学与机械工程系丹麦技术大学) 摘要：螺栓联接时结构中最重要的联接方式之一。螺栓和联接板的刚度是控制联接寿命的基本性质。与联接板刚度形成对照，螺栓刚度可以容易的计算出来，但是利用有限元和接触分析，找到联接板的刚度是可能的。在许多联接和实际应用情况下，做一个全部的有限元分析是不合适的。本文研究的目的是寻找螺栓联接刚度的简单表达式，包括联接板宽度是有限的情况。刚度的计算包括接触问题的解决都是基于有限元的，通过与刚度相关位移的定义，我们表达刚度是一个关于结构弹性能的函数。接触分析所使用的方法是不包含迭代过程的，结果与任意有用的结果作比较。提出了一个计算刚度的新方程。
2 L d 3 d 1 1 8 L ( d L) 2 2 2
E
最近 VDI 的建议又有改变。新的建议可以在文献[15]中找到。这个表达式简化后呈现在本文中：
d d a d a , gr km

接触和螺栓预紧力简易说明

接触和螺栓预紧⼒简易说明接触HypermeshStep 1: Launch the ANSYS Contact Manager1. Click the Contact Manager... button on the Utility Menu.The Ansys Contact Manager dialog is displayed at the top-left corner of the screen. At this point, you may want to adjust the size of the HyperMesh window.Step2: Create a new 3D contact1. Click New.. to create a new contact.The Create New Contact Pair dialog is displayed.2. Under Creation method choose Flexible.3. Under Contact type choose 3D.4. Under Create from choose Surface to surface.Step 3: Select the target body component1. Click Pick Target… to choose the target body component.The HyperMesh target selection panel is shown.2. Click the yellow comps button.3. Select the component named anzhuangban4. Click select and click proceed.The faces of the selected target body are extracted and displayed as shown below.Step 4: Select the target surface elements1. In the Target Elements Selection dialog, click the yellow Elements button twice.Target Elements is selected.2. Click proceed.3. Click Next.Step 5: Define the target component detailsThe Target Component Details dialog displays the default target component ID and type. You cannot modify these.1. Click the Next button in the Target Component Details dialog. A full model displays as shown in the following figure below. The Contact Components Selection dialog then displays..Step 6: Select the contact body components1. In the Contact Components Selection dialog, click the yellow Components button twice.The HyperMesh target selection panel is shown.2. Click the yellow comps button.3. Select the component named bolt.4. Click select then proceed.5. Click the Next button in the Contact Components Selection dialog.The edges of the selected contact body will be extracted and displayed as shown in the following figure.The Contact Elements Selection dialog will be displayed.Step 7: Select the contact elements1. Click the yellow Elements button twice.2. The HyperMesh target selection panel is shown.3. Pick one element on top of the upper face of the box.4. Click elems .The HyperMesh extended entity selector will be displayed. Select the by face selection method. The contact surface elements are selected as shown in the figure below.5. Click proceed .6. Click Next in the Selecting Contact Elements dialog. The Defining Contact Element Component dialog will be displayed. Step 8: Define the contact element component1. Click the Next button in the Contact Component Details dialog. The full model will be displayed as shown in the figure below.Step 9: Define the properties1. Click the Next button in the Contact Properties dialog. The Contact Material dialog is displayed..Step 10: Define the contact materialIt is optional to define a new material for the target/contact elements or to select an existing material. To define a new material:1. Under Define Material select the New radio button.2. Enter appropriate material values then click Next.3. 3. Go to Step 11 (below).To select an existing material:1. Under Define Material select the Same as radio button.2. Choose an existing contact material from the drop down menu.3. Click Next.4. Go to Step 11 (below).If do not want to assign any material properties:1. Under Define Material select the None radio button.2. Click Next.Step 11: Review the normalsThe Contact/Target Normal dialog is displayed, as well as the element normals. The target and contact elements normal should point towards each other. If they do not, the solution will not be performed correctly in ANSYS. Please review the normal vector direction and reverse them if needed.To show or hide the normals check or uncheck the appropriate box under Display Component and click the icon.You can adjust the size of the normals by changing the size value then pressing theicon.To reverse a normal check the appropriate box for TARGET or CONTACT and then click theicon.Click OK after reviewing the normals.AnsysContact Manager螺栓预紧⼒1.Select→Comp/Assembly→Select Comp/Assembly→by component name→OK →Replot2. Preprocessor→Modeling→Create→Element→Pretension→Pretensn Mesh→With Option →Divide at node→Picked Element→Box→→OK→→OK→→OK→3 Solution→Define Loads→Apply→Structural→Pret nsn SectnApply。

螺栓连接的有限元建模及仿真分析

螺栓连接的有限元建模及仿真分析辛鹏;万义强;徐琢【摘要】针对螺栓连接结构的仿真分析,建立了单体螺栓连接有限元模型和螺栓法兰有限元模型.理论计算和仿真分析均表明,在施加拧紧力矩后,装配应力主要产生在实体螺栓的螺头、垫圈和被连接件之间;与此同时,最大应力值也出现在螺母与螺杆连接处.模态分析表明,螺栓预紧力的大小对结构的影响很小.对于螺栓法兰连接结构,由装配引起的应力变化和分布也局限在各螺栓附近,其余部位影响甚小.为了提高仿真计算的效率和准确度,建议采用实体螺栓连接模型.【期刊名称】《车辆与动力技术》【年(卷),期】2015(000)002【总页数】5页(P58-62)【关键词】螺栓;法兰连接;预紧力;模态;装配应力【作者】辛鹏;万义强;徐琢【作者单位】北京理工大学机械与车辆学院,北京,100081;北京理工大学机械与车辆学院,北京,100081;北京理工大学机械与车辆学院,北京,100081【正文语种】中文【中图分类】U463螺栓连接作为一种可拆卸式的连接方式，广泛存在于各种机械设备中联结间厚度不大的场合.一般而言，对于各种机械式连接件，在工作过程中，应力集中和疲劳多数发生在连接部位，即螺栓附近，这对螺栓的寿命和连接精度有着重大的影响.因此，分析螺栓连接的应力产生有着重要的意义.由于螺栓连接中，连接件和被连接件相互之间的作用力比较复杂，因此，在有限元分析中，需要有针对性的简化.在螺栓连接中，螺栓预紧力和相互间接触是比较重要的两个特点，它们对结构的静态特性和动态特性的影响非常大.对于螺栓连接结构中的接触应力和连接刚度，许多科研工作者通过理论计算和有限元仿真，并加以试验验证，对螺栓连接进行了大量的研究分析［1］，得到了很多有价值的、可以借鉴的结论.在螺栓连接中，螺纹的接触和应力分析是有限元仿真中的难点.孙宇娟［2-3］等通过对螺纹的建模和分析，得到螺纹轴向载荷和应力分布规律，表明螺纹的形状和螺栓效应对螺栓结构的轴向载荷和应力分布的影响不大.这对我们简化螺栓模型提供了理论上的帮助.通过对螺栓连接应力分布的理论计算，基于有限元分析软件ANSYS，对螺栓连接进行精细化建模，并施以局部接触及螺栓预紧力，通过理论计算结果验证模型的准确性和实用性.1 螺栓连接模型强度计算校核螺栓连接的失效形式主要是螺栓杆部的损坏:在轴向变载荷的作用下，螺栓的时效多为螺栓的疲劳断裂，损坏的地方都是截面有剧烈变化因而有应力集中处.就破坏性质而言，约有90%的螺栓属于螺杆疲劳破坏.据统计资料表明，受变载荷的螺栓，如图1，在从螺母支撑面算起第一圈或第二圈螺纹破坏处损坏的约占65%，在光杆与螺纹部分交界处损坏的约占20%，在螺栓头与杆交界处损坏的约占15%.图1 变载荷受拉螺栓损坏统计例子中，建模螺栓为M10普通钢制螺栓，螺栓危险截面的拉伸应力螺栓危险截面的扭转切应力为式中:tanρv≈0.17，d2/d1≈1.05，tanλ =0.05，得对于钢制螺栓，可根据第四强度理论确定许用计算应力从公式来看，对于M10钢制紧螺栓连接，在拧紧时虽然受拉伸和扭转的联合作用，但计算时可按纯拉伸计算紧螺栓的强度，仅将所受的预紧力增大30%即可.对仅承受预紧力的紧连接螺栓，螺栓危险截面的应力值需小于许用应力式中:F为预紧力，N;d1为螺纹小径，mm;［σ］为螺栓材料的许用应力，MPa.2 螺栓连接有限元模型2.1 螺栓连接模型图2是局部简化版的螺栓连接结构，上下薄板通过M10的螺栓连接.显示螺栓连接处的网格划分及局部细节.对该实体连接模型，考虑到了真实的螺栓预紧力和接触［4］.实体螺栓连接模型是螺纹简化版的有限元模型，采用六面体单元建立螺栓、螺母、垫圈和薄板的详细模型.忽略螺栓和螺母的螺纹，在Hypermesh软件中螺母与上垫圈、螺头与下垫圈、上垫圈与上薄板、下垫圈与下薄板之间的接触采用面-面接触模型模拟［5-7］.预紧力的施加，取螺杆中部横截面插入PRETS179预紧力单元.为了便于观察螺栓螺杆内部因预紧力产生的应力分布，将有限元模型沿螺栓轴面切开，保留一半实体网格并对截面进行约束，以分析截面应力和螺杆应力分布情况，如图3所示.图2 实体螺栓连接整体模型图3 实体螺栓截面模型2.2 螺栓法兰连接模型考虑到单个螺栓连接虽然对研究螺栓内部应力分布情况具有较高的精确度和可信度，但是对由于螺栓连接施加拧紧力矩导致被连接件发生的局部变形，和由此产生的装配应力的分布情况并没有直接体现出来.在生产实际中，装配是一个至关重要的环节.而螺栓连接的广泛应用导致这一问题尤为突出.因此，搞清楚不同的装配过程所产生的装配应力的分布是很有必要的.图4所示为实际生产生活中广泛应用到的螺栓法兰连接结构:图4 螺栓法兰连接整体模型在该法兰连接结构中，上法兰和下法兰由6组圆周均布的M8螺栓连接.该实体模型与简化版的螺栓连接模型类似，是采用六面体solid185单元建立的螺栓、螺母、垫圈和法兰的详细模型.螺头与垫圈、垫圈与法兰、上法兰与下法兰的接触也采用面－面接触模型模拟.2.3 改造过的MPC法兰连接螺栓模型通过研究发现，由于螺栓预紧力的夹紧作用，在螺栓连接附近区域存在较大的应力分布，使得各零件紧密的连接在一起.针对这种情况，可以对实体螺栓法兰连接模型进行改造.删除预紧力单元，采用MPC法连接螺栓、螺母、垫圈以及法兰，如图5所示.并在垫圈下施加均布载荷.图5 MPC法兰螺栓连接模型材料参数的选取根据对热处理后的螺栓的最低要求，对于4.6级普通强度螺栓:屈服强度σy=392 MPa，屈强比值为0.6，ξu=10%;对于6.8级普通强度螺栓:屈服强度σy=588 MPa，屈强比值为0.8，ξu=10%。