ANSYS入门教程加载求解及后处理技术B

第4章加载求解及后处理技术4.1 荷载及其施加4.1.1荷载在ANSYS中荷载包括边界条件和作用力，对结构分析如下：位移、力、压力、温度、荷载即可施加在几何模型（关键点、硬点、线、面、体）上，也可施加在有限元模型（节点、单元）上，或者二者混合使用。

施加在几何模型上的荷载独立于有限元网格，不必为修改网格而重新加载；施加在有限元模型上且要修改网格，则必须先删除荷载再修改网格，然后重新施加荷载。

不管施加到何种模型上，在求解时荷载全部转换（自动或人工）到有限元模型上。

4.1.2 施加自由度约束在结构分析中自由度共有7个，自由度的方向均依从节点坐标系。

约束可施加在节点、关键点、线和面上。

⑴对节点施加自由度约束命令：D,NODE,Lab,VALUE,V ALUE2,NEND,NINC,Lab2,Lab3,Lab4,Lab5,Lab6NODE---拟施加约束的节点号，其值可取ALL、组件名。

Lab---自由度标识符，如UX、ROTZ等。

如为ALL，则为所有适宜的自由度。

V ALUE---自由度约束位移值或表式边界条件的表格名称。

V ALUE2---约束位移值的第二个数，如为复数输入时，V ALUE为实部，而V ALUE2为虚部。

NEND,NINC---节点编号范围和编号增量，缺省时NEND=NODE，NINC=1。

Lab2,Lab3,Lab4,Lab5,Lab6---其它自由度标识符，V ALUE对这些自由度也有效。

各自由度的方向用节点坐标系确定，转角约束位移用弧度输入例如：D,ALL,ALL !对所选节点的全部自由度施加约束D,18,UX,,,,,UY,UZ !对节点18的3个平动自由度全部施加约束D,20,UX,1.0e-4 !对节点20的UX施加约束，且约束位移值为1.0e-4D,22,UX,0.1,,25,,UY,ROTY!对节点22～25的UX,UY,ROTY施加约束，且位移值均为0.1⑷在节点上施加对称和反对称约束命令：DSYM,Lab,Normal,KCNLab---对称标识，如为SYMM则生成对称约束，如为ASYM则生成反对称约束。

ANSYS实体模型加载、求解及后处理步骤计算温度场步骤：1．定义标题和工作文件名1）定义标题：Utility Menu>Change Title2）定义工作文件名：Utility Menu>Change Jobname2.选择单元类型Main Menu>Proprecessor>Element Type>Add/Edit/Delete 出现一个“Element Type”对话框，点击“Add”,又出现一个“Library of Element Type”对话框，选择“Thermal Solid”，在右面的栏中选择“Brick 20Node 90”,单击“OK”。

3．定义材料属性1）设置材料密度Main Menu>Proprecessor>Material Props>Material Models 出现一个“Define Material Mode Behavior”对话框，在右面的对话框中双击“Thermal”，双击其下出现的“Density”，出现“Density for Material Number 1”的对话框，在“DENS”后面输入密度值；2）输入导热系数Main Menu>Proprecessor>Material Props>Material Models出现一个“Define Material Mode Behavior”对话框，在右面的对话框中双击“Thermal”，双击其下出现的“Conductivity”，双击“Isotropic”，出现一个“Conductivity for Material Number 1”的对话框，连续单击“Add Temperature”在“KXX”中输入导热系数值；3）定义比热在“Define Material Mode Behavior”对话框右面输入栏中，双击“Specific heat”，出现一个“Specific heat for Material Number 1”对话框，连续单击“Add Temperature”，在“Temperature”中输入温度，在“C”中输入与温度对应的比热系数；4）输入对流系数在“Define Material Mode Behavior”对话框右面输入栏中，双击“Convection or Film Coef”，出现一个“Convection or Film Coefficient for Material Number 1”对话框，在“Temperature”中输入温度，在“HF”后面输入与温度对应的对流数。

ansys命令流----前后处理和求解常用命令之求解与后处理The ANSYS command stream - before and after the treatment and solving common commands of solving and postprocessing of.Txt is a mountain fox, you told me what all, standing in the place nearest to you, look you smile to others, even if the heart is all the pain just to keep your eye out. The glare of the bottom of every act and every move white, let me understand what is pure damage. 3 /soluU /solu enters the solver3.1 plus boundary conditionsU, D, node, lab, value, Value2, nend, Ninc, lab2, lab3,...... LaB6 defines node displacement constraintsNode: the node number of the pre displacement constraint. If it is all, all selected nodes are fully bound, and nend and ninc. are ignored at this timeLab:, UX, uy, UZ, ROTx, ROTY, Rotz, allThe value of Value, value2: degrees of freedom (default 0)Nend, ninc: node range is: node-nend, the number interval is NincLab2-lab6: applies lab2-lab6 to the selected node with the same value.Note: discussed in the node coordinate system3.2 set the solution optionU, antype, status, ldstep, substep, actionStatic analysis of antype:, static and or 1Buckling analysis of buckle or 2Modal or 3 modal analysisTransient analysis of trans or 4Status: new reanalysis (default), which will be ignored later Rest reanalysis is valid only for static, full, and transionLdstep: specifies which load step to proceed from the analysis and defaults to the maximum runn number (the last step of the analysis point)Substep: specifies which sub step to proceed from the analysis. The default is the highest number of sub steps in the runn file in this directoryAction, continue: continues to analyze the specified ldstep, substepExplanation: there are two types of continuous analysis (interrupted for some reason)Singleframe restart: continues from the stop pointRequired file: jobname.db must be saved immediately after initial solutionJobname.emat cell matrixJobname.esav or.Osav: if.Esav is broken, change.Osav to.EsavResults file: is not necessary, but if so, the results of subsequent analysis will be well attached to itNote: if the initial analysis generates a.Rdb,.Ldhi, or rnnn file. Deletion must be followed by subsequent analysisStep: (1) enter ANASYS with the same job name(2) enter the solver and restore the database(3) antype, rest(4) additional load is specified(5) specify whether to use the existing matrix (jobname.trl) (default rebuild)Kuse: 1 uses an existing matrix(6) solvingMultiframe restart: continues from any result with no result(no need)U, PRED, sskey -- -- lskey... Whether to open the predictor in nonlinear analysisSskey: off does not make predictions (when the degree of freedom is rotated or when SOLID65 is used, default is off)The first step was to predict on (unless there is a rotational degree of freedom or when using the SOLID65 default is on)- - unused variable zoneLskey: off does not predict when crossing load steps (default)On predicts when crossing load steps (at this time sskey must be simultaneous on)Note: the default value for this command assumes that solcontrol is onDoes u autots and key use automatic time steps?Key:on: when solcontrol is on, the default is onOff: when solcontrol is off, the default is off1: records in the.Log file "1" by the program selection (when solcontrol is on and does not occur the autots command"Note: the step size predictor and the two step size are alsoused when using the automatic time stepU, NROPT, option -- -- adptky specifies the options for Newton Ralph Xun Fa's solutionOPTION: AUTO: program selectionFULL: completely Newton Ralph Xun FaMODI: revised by Newton Ralph Xun FaINIT: using the initial stiffness matrixUNSYM: complete Newton Ralph Xun Fa, and allows asymmetric stiffness matricesADPTKY:ON: uses adaptive drop factorOFF: no adaptive drop factor is usedU, NLGEOM, KEYKEY: OFF: does not include geometric nonlinearity (default)ON: including geometric nonlinearityU, ncnv, kstop, dlim, itlim, etlim, cplim, terminate the analysis optionsKstop: 0, if the solution is not convergent, does not terminate the analysis1 if the solution does not converge, terminate the analysis and the program (default)2 if the solution does not converge, terminate the analysis, but do not terminate the programDlim: maximum displacement limit, defaults to 1.0e6Itlim: cumulative iteration limit, default to infinityEtlim: program execution time (seconds) limit, the default is infiniteCplim:cpu time (seconds) limit, default to infinityThe U, solcontrol, key1, key2, Key3, and VTOL specify whether or not to use some nonlinear solutions for default valuesKey1: on activates some optimized default values (default)CNVTOL, Toler=0.5%Minref=0.01 (for force and moment)NEQIT the maximum number of iterations is set between 15~26 depending on the modelARCLEN uses the more advanced method of ansys5.3 than using the arc length rulePRED unless ROTx, y, Z, or SOLID65 are openedLNSRCH automatically opens when exposedCUTCONTROL, Plslimit=15%, npoint=13SSTIF opens when NLGEOM, onNROPT, adaptkey closes (unless the frictional contact exists; the unit 12,26,48,49,52 exists; when the plastic is present and there is a unit 20,23,24,60)AUTOS is chosen by the programOff does not use these default valuesKey2: on checks the contact state (key1 at on)At this point, the time step is based on the contact state of the unit (assuming keyopt (7))When keyopt (2) =on, the time step is guaranteed to be small enoughKey3: stress loading stiffness control, use default values as much as possibleNull: by default, certain units include stress loading, stiffening, and certain ones (excluding)Nopl: does not include stress stiffening for any elementIncp: for some elements including stress load stiffening(check)Vtol:U, outres, item, freq, and CNAME specify the solution information for writing to the databaseItem: all all the solutionsBasic only writes nsol, rsol, nload, STRsNsol node freedomRsol node acting loadNload nodal loads and input strain loads (?)STRs node stressIf n is freq:, it is written once every n step (including the last step)None: does not write entries in this load stepAll: writes every stepLast: writes only the last step (default when static or transient)3.3 define the load stepThe U, nsubst, nsbstp, nsbmx, nsbmn, and carry specify the number of sub steps for this load stepNsbstp: the number of sub steps of this load stepIf automatic time step using autots, the number of the first definition step length; if solcontrol is open, and 3D surface to surface contact element is used, the default is 1-20; if solcontrol is open, there is no 3D contact element, the default is 1 steps; if the solcontrol is closed, the default value is specified as before; not previously specified, the default is 1)Nsbmx, nsbmn: at most, the minimum number of steps (if the automatic time step is turned on)?U time, time specifies the end time of the load stepNote: the end of the first step shall not be "0""U F, node, lab, Ninc, value, Value2, nend, plus concentrated load at the specified nodeNode: node numberLab:, Fx, Fy, Fz, Mx, My, MzValue: force sizeThe second magnitude of the force of value2: (if there is a complex load)Nend, Ninc: apply the same force on the node from node to nend (increment Ninc)Note: (1) the nodal force is defined in the nodal coordinate system, and the positive and negative forces are in direct agreement with the nodal coordinate axisU, SFA, area, lkey, lab, value, and Value2 add loads on the specified surfaceArea: n surface numberAll all selected numbersLkey: if it is the surface of the body, ignore this itemLab: presValue: pressure valueU, SFBEAM, ELEM, LKEY, LAB, VALI, VALJ, VAL2I, VAL2J, IOFFST, JOFFSTApply line load to the beam elementThe ELEM: cell number can be ALL, that is, the selected cellLKEY: surface mounted type number, see unit introduction. For BEAM188, 1 is vertical; 2 is transverse; 3 is tangentialPressure values at VALI, VALJ:, I, and J nodesVAL2I, VAL2J: is useless for the momentIOFFST, JOFFST:, line distance, I, J node distanceU, lswrite, lsnum write the load and load options into the load fileLsnum: the suffix of the load step file name, that is, the number of loading stepsWhen the stat column shows the current step numberInit reset to "1""The default is to add 1 to the current step"3.3.1 attention1. add as much load as possible without focusing so as to avoid singularitiesThe tangential load on the 2. plane must depend on the surface element3.4 load stepsU, lssolve, lsmin, lsmax, lsinc read and solve multiple loading stepsLsmin, lsmax, lsinc: load step file range4 /post1 (general postprocessing)U, set, lstep, sbstep, fact, king, time, angle, and nset set the data read from the result fileLstep: load stepsSbstep: child steps and defaults to the last stepTime: point of time (if the arc length rule does not)Nset:data set numberU, dscale, WN, dmult display deformation ratioWn: window number (or all), defaults to 1Dmult, 0 or Auto: automatically make the maximum deformation picture 5% of the length of the componentU, pldisp, and Kund display the structure of deformationKund:0 only shows the structure after deformation1 shows the structure before deformation and after deformation2 shows the deformation structure and the edge of the undeformed structureU, *get, par, node, N, u, X (y, z) obtain the X (y, z) shift of node n to parameter parEquivalent to the function UX (n), uy (n), UZ (z)Node (x, y, z): get the (x, y, z) node numberArnode (x, y, z): get the surface connected to the node nNote: this command can also be used with the /solu moduleU, fsum, lab, item, summation of nodal forces and moments of a unitLab: empty sum in the whole DeCarr coordinate systemRsys sums up in the current active rsys coordinate systemItem: empty sum for all selected units (not including contact elements)Cont: only sum the contact nodesU, PRSSOL, ITEM, COMP, print BEAM188, BEAM189 cross section resultsDescription: only when the calculation has not yet exited the ANSYS can be used and re entered the ANSYS is not availableItem comp cross section data and component markStress components of S, COMP, X, XZ and YZPRIN, S1, S2, S3, principal stress, SINT stress intensity, and SEQV equivalent stressEPTO COMP total strainPRIN total principal strain, strain strength and equivalent strainEPPL COMP plastic strain componentPRIN principal plastic strain, plastic strain strength, and equivalent plastic strainU, plnsol, item, comp, Kund, fact draw nodes, resulting in a continuous contour lineItem: project (see table below)Comp: componentKund: 0 does not display an undeformed structure1 deformation and deformation overlap2 deformation contours and undeformed edgesFact:'s coefficient of proportionality for exposure to 2D displays defaults to 1Item comp discriptionU, x, y, Z, sum shiftRot, x, y, Z, sum cornersS, x, y, Z, XY, YZ, XZ stress components1, 2, 3 principal stressesInt, EQV stress, intensity, equivalent stressEPEO, x, y, Z, XY, YZ, XZ total displacement components 1,2,3 principal strainInt, EQV strain, intensity, equivalent strainEPEL, x, y, Z, XY, YZ, and XZ elastic strain components 1, 2, 3 elastic principal strainInt, EQV, elastic intensity, elastic equivalent strain EPPL, x, y, Z, XY, YZ, XZ plastic strain componentsU PRNSOL, item, comp print select the node results Item: project (see above)Comp: componentU, PRETAB, LAB1, LAB2,...... Plotting unit table data along the length of units along LAB9LABn: null: column names specified by all ETABLE commandsColumn name: the column name specified by any ETABLE commandU, PLLS, LABI, LABJ, FACT, KUND, drawing unit table data along the unit length directionUnit table name of LABI: node IUnit table name of LABJ: node JFACT: display scale, default to 1Kund: 0 does not display an undeformed structure1 deformation and deformation overlap2 deformation contours and undeformed edges5 /post26 (time course postprocessing)U, nsol, NVAR, node, item, comp, nameIn the time course, the ordinal number of the node variable is defined in the processorNVAR: variable number (from 2 to NV (defined by numvar))Node: node numberItem compU, x, y, ZRot, x, y, ZU, ESOL, NVAR, ELEM, NODE, ITEM, COMP, and NAME store the results into variablesNVAR: variable number, more than 2ELEM: unit numberNODE: the node number of the unit determines which amount to store the unit and, if empty, gives the average valueITEM:COMP:NAME: 8 character variable name, defaults to ITEM plus COMPU, rforce, NVAR, node, item, comp, and name specify the node force data to be storedNvar: variable numberNode: node numberItem compF, x, y.zM, x, y, ZName: gives this variable a name, 8 charactersU, add, IR, IA, IB, IC, name, - - - -, facta, factb, factc Add the IA, IB, and IC variables to the IR variableIR, IA, IB, IC: variable numberThe name of the name: variableU, /grid, keyKey: "0" or "off" without network"1" or "on" XY network"2" or "X" is only X-ray"3" or "Y" has only y linesU, xvar, nN: "0" or "1" takes the X axis as the time axis"N" represents the X axis variable "n"""-1"?U, /axlab, axis, lab define the axis of the markAxis: "X" or "Y""The lab: flag can be up to 30 characters longU, plvar, NVAR, nvar2,...... Nvar10 draws the variable to be displayed (as a ordinate)U, prvar, nvar1,...... Nvar6 lists the variables to display6 PLOTCONTROL menu commandU, PBC, ilem,...... The key, min, Max, and ABS display symbols and values on the displayThe displacement constraint added by item: uRot corner constraintKey: 0 does not display symbols1 display symbols2 display symbols and valuesThe U, /SHOW, FNAME, EXT, VECT, and NCPL determine the graphicaldisplay of the device and other parametersFNAME: X11: screenFile name: each graphic will generate a series of graphic filesEach of the JPEG: graphics generates a series of JPEG graphics filesDescription: there is no need to use this command, graphics files need to be calculated and then output7 parametric design languageU, *do, par, ival, Fval, and inc define the beginning of a do loopPar: loop control variablesIval, Fval, Inc: start value, final value, step size (positive, negative)U *enddo defines the end of a do loopU, *if, val1, oper, val2, base: conditional statementsVal1 (val2:), the value to be compared (also characters, enclosed in quotes)Oper: logical operation (when the real number is compared, the error is 1e-10)EQ, NE, lt, GT, Le, Ge, ablt, abgtBase: behavior when the oper result is a logical truthLable: user defined line labelsStop: will jump out of ANASYSExit: jumps out of the current do loopCycle: jumps to the end of the current do loopThen: makes up the If-Then-Else structureNote: not allowed to jump out of, jump into a do, if loop to label sentence8 theoretical manualSolution of 1. equations: (1) direct solution; (2) iterative solution(1) direct solution: A. sparse matrix method and B. wave front methodA. sparse matrix method: accounting for large memory, but the number of operations less; by changing the order of stiffness matrix, so that non-zero elements minimumB. wavefront method: small memoryWavefront is the number of equations activated when no cell has been solved(2) iterative solution: JCG method, PCG method, ICCG methodJCG method: solvable real numbers, symmetric and unsymmetric matricesPCG method: efficient solution of various matrices (including morbid state), but only the real and symmetric matrixICCG: similar to JCG, but stronger2. strain density, equivalent strain, stress density, equivalent stress(1) strain density (strain, intensity);Strain densityAre the three principal strains(2) equivalent strainEffective Poisson's ratio: the user is set by the avprin command;0 (if not set)(3) stress density (stress, intensity);Stress density(4) equivalent stressEquivalent stress or if there is (elastic state)。

手把手教你用ANSYS workbench 本文的目的主要是帮助那些没有接触过ansys workbench的人快速上手使用这个软件。

在本文里将展示ansys workbench如何从一片空白起步，建立几何模型、划分网格、设置约束和边界条件、进行求解计算，以及在后处理中运行疲劳分析模块，得到估计寿命的全过程。

一、建立算例打开ansys workbench，这时还是一片空白。

首先我们要清楚自己要计算的算例的分析类型，一般对于结构力学领域，有静态分析（Static Structural）、动态分析（Rigid Dynamics）、模态分析（Modal）。

在Toolbox窗口中用鼠标点中算例的分析类型，将它拖出到右边白色的Project Schematic窗口中，就会出现一个算例框图。

比如本文选择进行静态分析，将Static Structural条目拖出到右边，出现A框图。

在算例框图中，有多个栏目，这些是计算一个静态结构分析算例需要完成的步骤，完成的步骤在它右边会出现一个绿色的勾，没有完成的步骤，右边会出现问号，修改过没有更新的步骤右边会出现循环箭头。

第二项EngineeringData 已经默认设置好了钢材料，如果需要修改材料的参数，直接双击点开它，会出现Properties窗口，一些主要用到的材料参数如下图所示：点中SN曲线，可在右侧或者下方的窗口中找到SN曲线的具体数据。

窗口出现的位置应该与个人设置的窗口布局有关。

二、几何建模现在进行到第三步，建立几何模型。

右键点击Grometry条目可以创建，或者在Toolbox窗口的Component Systems下面找到Geometry条目，将它拖出来，也可以创建，拖出来之后，出现一个新的框图，几何模型框图。

双击框图中的Geometry，会跳出一个新窗口，几何模型设计窗口，如下图所示：点击XYPlane，再点击创建草图的按钮，表示在XY平面上创建草图，如下图所示：右键点击XYPlane，选择Look at，可将右边图形窗口的视角旋转到XYPlane 平面上：创建了草图之后点击XYPlane下面的Sketch2（具体名字可按用户需要修改），再点击激活Sketching页面：在Sketching页面可以创建几何体，从基本的轮廓线开始创建起，我们现在右边的图形窗口中随便画一条横线：画出的横线长度是鼠标随便点出来的，并不是精确地等于用户想要的长度，甚至可能与想要的长度相差好多个数量级。

ANSYS基础教程—加载&求解关键字：ANSYS ANSYS常用命令力载荷求解器多重载荷步信息化调查找茬投稿收藏评论好文推荐打印社区分享本文主要讲述五种载荷类型中剩下一种载荷—集中载荷, 比如应力分析中的节点载荷，包括以下内容：集中载荷、节点坐标、求解器、多重载荷步。

概述·迄今为止, 我们已经知道了如何施加以下类型的载荷:–位移(DOF 约束)–压力和对流载荷(表面载荷)–重力(惯性载荷)–“结构”温度(体载荷)这些载荷占了五种载荷类型中的4种。

本文将讲述剩下的一种载荷—集中载荷, 比如应力分析中的节点载荷。

·将就以下问题进行讨论:A. 集中载荷B. 节点坐标C. 求解器D. 多重载荷步A. 力载荷·一个力就是可以在一个节点或关键点处施加的集中载荷(也可以叫“点载荷”)·和力一样，点载荷适合于线状模型，如梁，桁架，弹簧等。

在实体单元或壳单元中, 点载荷往往引起应力奇异，但当您忽略了附近的应力时，它仍然是可接受的。

记住，您可以通过选择来忽略附近施加了点载荷的单元。

·在左下角展示的二维实体单元中，我们注意到在加力位置出现最大应力SMAX (23,854)。

当在力附近的节点和单元不被选中时，SMAX (12,755)就会移到底部角点处，这是由于在该角点处约束引起的另一处应力奇异。

通过不选底部角点附近的节点和单元，您就可以在上孔附近得到预期的应力SMAX (8,098)。

注意，对于轴对称模型:·在全部360°范围内输入力的值。

·同样在全部360°范围内输出力的值(反力)。

·例如, 设想一个半径为r的圆柱形壳体边缘施加有P lb/in 的载荷。

把这个载荷施加在二维轴对称壳体模形上(比如SHELL51单元), 您就要施加一2πrP的力。

·施加一个力需要有以下信息:–节点号(您可以通过施取确定)–力的大小(单位应与您正在使用的单位系统保持一致)–力的方向—FX, FY, 或FZ使用:–Solution > -Loads-Apply > Force/Moment–或命令FK或F·问题:在哪一个坐标系中FX, FY, 和FZ 有说明？B.节点坐标系·所有的力，位移，和其它与方向有关的节点量都可以在节点坐标中说明。