Building a Model in AnsysWord下载.docx

1、Command（s）:/FILNAME GUI:Utility MenuFileChange JobnameThe /FILNAME command is valid only at the Begin level. It lets you change the jobname even if you specified an initial jobname at ANSYS entry. The jobname applies only to files you open after using /FILNAME and not to files that were already open

2、. If you want to start new files （such as the log file, Jobname.LOG, and error file Jobname.ERR） when you issue /FILNAME, set the Key argument on /FILNAME to 1. Otherwise, those files that were already open will still have the initial jobname. Defining an Analysis Title The /TITLE command （Utility M

3、enuChange Title）, defines a title for the analysis. ANSYS includes the title on all graphics displays and on the solution output. You can issue the /STITLE command to add subtitles; these will appear in the output, but not in graphics displays.Defining Units The ANSYS program does not assume a syste

4、m of units for your analysis. Except in magnetic field analyses, you can use any system of units so long as you make sure that you use that system for all the data you enter. （Units must be consistent for all input data.）For micro-electro mechanical systems （MEMS）, where dimensions are on the order

5、of microns, see the conversion factors in System of Units in the ANSYS Coupled-Field Analysis Guide.Using the /UNITS command, you can set a marker in the ANSYS database indicating the system of units that you are using. This command does not convert data from one system of units to another; it simpl

6、y serves as a record for subsequent reviews of the analysis.Defining Element Types The ANSYS element library contains more than 150 different element types. Each element type has a unique number and a prefix that identifies the element category: BEAM4, PLANE77, SOLID96, etc. The following element ca

7、tegories are available:BEAMCIRCUitCOMBINationCONTACtFLUIDHF （High Frequency）HYPERelasticINFINiteINTERfaceLINKMASSMATRIXMESHPIPEPLANEPRETS （Pretension）SHELLSOLIDSOURCe SURFaceTARGEtTRANSducerUSERVISCOelastic （or viscoplastic）The element type determines, among other things: The degree-of-freedom set （

8、which in turn implies the discipline-structural, thermal, magnetic, electric, quadrilateral, brick, etc.） Whether the element lies in two-dimensional or three-dimensional space.BEAM4, for example, has six structural degrees of freedom （UX, UY, UZ, ROTX, ROTY, ROTZ）, is a line element, and can be mod

9、eled in 3-D space. PLANE77 has a thermal degree of freedom （TEMP）, is an eight-node quadrilateral element, and can be modeled only in 2-D space.You must be in PREP7, the general preprocessor, to define element types. To do so, you use the ET family of commands （ET, ETCHG, etc.） or their GUI path equ

10、ivalents; see the ANSYS Commands Reference for details. You define the element type by name and give the element a type reference number. For example, the commands shown below define two element types, BEAM4 and SHELL63, and assign them type reference numbers 1 and 2 respectively.ET,1,BEAM4ET,2,SHEL

11、L63This table of type reference number versus element name is called the element type table. While defining the actual elements, you point to the appropriate type reference number using the TYPE command （Main MenuPreprocessorCreateElementsElem Attributes）.Many element types have additional options,

12、known as KEYOPTs, and are referred to as KEYOPT（1）, KEYOPT（2）, etc. For example, KEYOPT（9） for BEAM4 allows you to choose results to be calculated at intermediate locations on each element, and KEYOPT（3） for SHELL63 allows you to suppress extra displacement shapes. You can specify KEYOPTs using the

13、ET command or the KEYOPT command （Main MenuElement TypeAdd/Edit/Delete）.Defining Element Real Constants Element real constants are properties that depend on the element type, such as cross-sectional properties of a beam element. For example, real constants for BEAM3, the 2-D beam element, are area （

14、AREA）, moment of inertia （IZZ）, height （HEIGHT）, shear deflection constant （SHEARZ）, initial strain （ISTRN）, and added mass per unit length （ADDMAS）. Not all element types require real constants, and different elements of the same type may have different real constant values.You can specify real con

15、stants using the R family of commands （R, RMODIF, etc.） or their equivalent menu paths; see the ANSYS Commands Reference for further information. As with element types, each set of real constants has a reference number, and the table of reference number versus real constant set is called the real co

16、nstant table. While defining the elements, you point to the appropriate real constant reference number using the REAL command （Main MenuWhile defining real constants, keep these rules and guidelines in mind: When using one of the R commands, you must enter real constants in the order shown in Table

17、4.n.1 for each element type in the ANSYS Elements Reference. For models using multiple element types, use a separate real constant set （that is, a different REAL reference number） for each element type. The ANSYS program issues a warning message if multiple element types reference the same real cons

18、tant set. However, a single element type may reference several real constant sets. To verify your real constant input, use the RLIST and ELIST commands, with RKEY = 1 （shown below）. RLIST lists real constant values for all sets. The command ELIST,1 produces an easier-to-read list that shows, for eac

19、h element, the real constant labels and their values. ELIST ListAttributes + RealConstAttributes OnlyNodes + AttributesNodes + Attributes + RealConstRLIST PropertiesAll Real ConstantsSpecified Real Const For line and area elements that require geometry data （cross-sectional area, thickness, diameter

20、, etc.） to be specified as real constants, you can verify the input graphically by using the following commands in the order shown:/ESHAPE and EPLOT PlotCtrlsStyleSize and ShapePlotElementsANSYS displays the elements as solid elements, using a rectangular cross-section for link and shell elements an

21、d a circular cross-section for pipe elements. The cross-section proportions are determined from the real constant values.Creating Cross SectionsIf you are building a model using BEAM44, BEAM188, or BEAM189, you can use the section commands （SECTYPE, SECDATA, etc.） or their GUI path equivalents to de

22、fine and use cross sections in your models. See Beam Analysis and Cross Sections in the ANSYS Structural Analysis Guide for information on how to use the BeamTool to create cross sections.Defining Material Properties Most element types require material properties. Depending on the application, mater

23、ial properties can be linear （see Linear Material Properties） or nonlinear （see Nonlinear Material Properties）.As with element types and real constants, each set of material properties has a material reference number. The table of material reference numbers versus material property sets is called th

24、e material table. Within one analysis, you may have multiple material property sets （to correspond with multiple materials used in the model）. ANSYS identifies each set with a unique reference number.While defining the elements, you point to the appropriate material reference number using the MAT co

25、mmand. Linear Material Properties Linear material properties can be constant or temperature-dependent, and isotropic or orthotropic . To define constant material properties （either isotropic or orthotropic）, use one of the following:MP Main Menu Preprocessor Material Props Material Models（See Materi

26、al Model Interface for details on the GUI.）You also must specify the appropriate property label; for example EX, EY, EZ for Youngs modulus , KXX, KYY, KZZ for thermal conductivity, and so forth. For isotropic material you need to define only the X-direction property; the other directions default to

27、the X-direction value. For example:MP,EX,1,2E11 ! Youngs modulus for material ref. no. 1 is 2E11MP,DENS,1,7800 ! Density for material ref. no. 1 is 7800MP,KXX,3,43 ! Thermal conductivity for material ref. no 1 is 43Besides the defaults for Y- and Z-direction properties （which default to the X-direction properties）, other material property defaults are built in to reduce the amount of input. For example, Poissons ratio （NUXY） defaults to 0.3,