第3章ANSYS 的前处理技术3.1有限单元类型的选取有限元类型选取指令：ET, ITYPE, Ename, KOP1, KOP2, KOP3, KOP4, KOP5, KOP6, INOPRDefines a local element type from the element library.ITYPEArbitrary local element type number. Defaults to 1 + currentmaximum.EnameElement name (or number) as given in the element library in Chapter4 of the ANSYS Elements Reference. The name consists of a categoryprefix and a unique number, such as BEAM3. The category prefix of the name (BEAM for the example) may be omitted but is displayed upon output for clarity. If Ename = 0, the element is defined as a null element.KOP1, KOP2, KOP3, KOP4, KOP5, KOP6KEYOPT values (1 through 6) for this element, as described in the ANSYS Elements Reference.INOPRIf 1, suppress all element solution printout for this element type 举例：PLANE13 has a 2-D magnetic, thermal, electrical, piezoelectric, and structural field capability with limited coupling between the fields. PLANE13 is defined by four nodes with up to four degrees of freedom per node. The element has nonlinear magnetic capability for modeling B-H curves or permanent magnet demagnetization curves. PLANE13 has large deflection and stress stiffening capabilities. When used in purely structural analyses, PLANE13 also has large strain capabilities. See PLANE13 in the ANSYS, Inc. Theory Reference for more details about this element. Other coupled-field elements are SOLID5, SOLID98, and SOLID62.KEYOPT(1)Element degrees of freedom:0-- AZ degree of freedom2-- TEMP degree of freedom3-- UX, UY degrees of freedom4-- UX, UY, TEMP, AZ degrees of freedom6-- VOLT, AZ degrees of freedom7-- UX, UY, VOLT degrees of freedomKEYOPT(2)Extra shapes:0-- Include extra shapes1-- Do not include extra shapesKEYOPT(3)Element behavior:0-- Plane strain (with structural degrees of freedom)1-- Axisymmetric2-- Plane stress (with structural degrees of freedom)KEYOPT(4)Element coordinate system defined:0--Element coordinate system is parallel to the global coordinate system1-- Element coordinate system is based on the element I-J side KEYOPT(5)Extra element output:0-- Basic element printout1-- Repeat basic solution for all integration points2-- Nodal stress printout3.2 点、线、面的产生方法3.2.1 电磁铁磁场分析步骤1：画出欲求解电磁场物体的结构图步骤2：求关键点（能决定物体形状的点的坐标）/PREP7 ！开始前处理程序/UNITS, SI ！选取国际单位EMUNIT, MKS ！选取（米、千克、秒）电磁单位制LOCAL，11，0 ！选取直角坐标系统LOCAL, KCN, KCS, XC, YC, ZC, THXY, THYZ, THZX, PAR1, PAR2 Defines a local coordinate system by a location and orientation. DATABASE: Coordinate SystemKCNArbitrary reference number assigned to this coordinate system. Must be greater than 10. A coordinate system previously defined with this number will be redefined.KCSCoordinate system type:0 or CART —Cartesian1 or CYLIN —Cylindrical (circular or elliptical)2 or SPHE —Spherical (or spheroidal)3 or TORO —ToroidalXC, YC, ZCLocation (in the global Cartesian coordinate system) of the origin of the new coordinate system.THXYFirst rotation about local Z (positive X toward Y).THYZSecond rotation about local X (positive Y toward Z).THZXThird rotation about local Y (positive Z toward X).PAR1Used for elliptical, spheroidal, or toroidal systems. If KCS = 1 or 2, PAR1is the ratio of the ellipse Y-axis radius to X-axis radius (defaults to 1.0 (circle)). If KCS = 3, PAR1 is the major radius of the torus.PAR2Used for spheroidal systems. If KCS = 2, PAR2 = ratio of ellipse Z-axis radius to X-axis radius (defaults to 1.0 (circle)).x 1步骤3: 由点联线LSTR, 1, 2 ! L1 第一条线（Straight line）LSTR, 2, 3LSTR, 3, 4LSTR, 4, 1LSTR, 5, 6 ! L5LSTR, 6, 7LSTR, 7, 8LSTR, 8, 5LSTR, 9, 10LSTR, 10, 11 ! L10LSTR, 11, 12LSTR, 12, 9LSTR, 6, 13LSTR, 13, 14LSTR, 14, 15 ! L15 LSTR, 15, 10LSTR, 11, 16LSTR, 16, 17LSTR, 17, 18LSTR, 18, 7 ! L20 LSTR, 19, 20LSTR, 20, 21LSTR, 21, 22LSTR, 22, 19LSTR, 14, 19 ! L25 LSTR, 15, 16LSTR, 17, 22 ! L27步骤4: 指定线段剖分单元边长(根据磁场分析精度的需要) LESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIVSpecifies the divisions and spacing ratio on unmeshed lines.NL1Number of the line to be modified. If ALL, modify all selected lines [LSEL]. If NL1= P, graphical picking is enabled and all remaining command fields are ignored (valid only in the GUI). A component name may also be substituted for NL1.SIZEIf NDIV is blank, SIZE is the division (element edge) length. The number of divisions is automatically calculated from the linelength (rounded upward to next integer). If SIZE is zero (or blank), use ANGSIZ or NDIV.ANGSIZThe division arc (in degrees) spanned by the element edge (except for straight lines, which always result in one division).NDIVIf positive, NDIV is the number of element divisions per line.SPACESpacing ratio. If positive, nominal ratio of last division size to first division size (if > 1.0, sizes increase, if < 1.0, sizesdecrease). If negative, |SPACE| is nominal ratio of centerdivision(s) size to end divisions size. Ratio defaults to 1.0(uniform spacing). For layer-meshing, a value of 1.0 normally is used. If SPACE= FREE, ratio is determined by other considerationsKFORCKFORC 0-3 are used only with NL1 = ALL. Specifies which selected lines are to be modified.0—Modify only selected lines having undefined (zero) divisions.1—Modify all selected lines.2—Modify only selected lines having fewer divisions (including zero) than specified with this command.3—Modify only selected lines having more divisions than specified with this command.4—Modify only nonzero settings for SIZE, ANGSIZ, NDIV, SPACE, LAYER1, and LAYER2. If KFORC= 4, blank or 0 settings remain unchanged.LAYER1Layer-meshing control parameter. Distance which defines thethickness of the inner mesh layer, LAYER1. Elements in this layer are uniformly-sized with edge lengths equal to the specifiedelement size for the line (either through SIZE or line-length/NDIV).A positive value for LAYER1 is interpreted as an absolute length,while a negative value in interpreted as a multiplier on thespecified element size for the line. As a general rule, theresulting thickness of the inner mesh layer should be greater than or equal to the specified element size for the line. If LAYER1 = OFF, layer-meshing control settings are cleared for the selected lines. The default value is 0.0LAYER2Layer-meshing control parameter. Distance which defines thethickness of the outer mesh layer, LAYER2. Elements in this layer transition in size from those in LAYER1to the global element size.A positive value of LAYER2 is interpreted as an absolute length,while a negative value is interpreted as a mesh transition factor.A value of LAYER2 = -2 would indicate that elements shouldapproximately double in size as the mesh progresses normal to LAYER1.The default value is 0.0.KYNDIV0, No, and Off means that SmartSizing cannot override specifieddivisions and spacing ratios. Mapped mesh fails if divisions do not match. This defines the specification as “hard”.1, Yes, and On means that SmartSizing can override specifieddivisions and spacing ratios for curvature or proximity. Mapped meshing can override divisions to obtain required matchingdivisions. This defines the specification as“ soft”.一般采用将线段指定划分为多少个单元, 即只用下述指令中的红色部分, 其他部分不管.LESIZE, NL1, SIZE, ANGSIZ, NDIV, SPACE, KFORC, LAYER1, LAYER2, KYNDIV根据对电磁铁磁场分布的定性分析, 可确定各线段有限元网格剖分的稀密程度。
