土木工程翻译NodeStructural.doc

PLANE82 2-D 8-Node Structural SolidElement DescriptionPLANE82 is a higher order version of the two-dimensional, four-node element (PLANE42). It provides more accurate results for mixed (quadrilateral-triangular) automatic meshes and can tolerate irregular shapes without as much loss of accuracy. The 8-node elements have compatible displacement shapes and are well suited to model curved boundaries.The 8-node element is defined by eight nodes having two degrees of freedom at each node: translations in the nodal x and y directions. The element may be used as a plane element or as an axisymmetric element. The element has plasticity, creep, swelling, stress stiffening, large deflection, and large strain capabilities. Various printout options are also available. See the ANSYS, Inc.Theory Reference for more details about this element. See PLANE83 for a description of an axisymmetric element which accepts nonaxisymmetric loading.Input DataThe geometry, node locations, and the coordinate system for this element are shown in PLANE82.A triangular-shaped element may be formed by defining the same node number for nodes K, L and O. A similar, but 6-node, triangular element is PLANE2. Besides the nodes, the element input data includes a thickness (TK) (for the plane stress option only) and the orthotropic material properties. Orthotropic material directions correspond to the element coordinate directions. The element coordinate system orientation is as described in Coordinate Systems.Element loads are described in Node and Element Loads. Pressures may be input as surface loads on the element faces as shown by the circled numbers on PLANE82. Positive pressures act into the element. Temperatures and fluences may be input as element body loads at the nodes. The node I temperature T(I) defaults to TUNIF. If all other temperatures are unspecified, they default to T(I). If all corner node temperatures are specified, each midside node temperature defaults to the average temperature of its adjacent corner nodes. For any other input temperature pattern, unspecified temperatures default to TUNIF. Similar defaults occurs for fluence except that zero is used instead of TUNIF.The nodal forces, if any, should be input per unit of depth for a plane analysis (except for KEYOPT(3) = 3) and on a full 360 basis for an axisymmetric analysis. KEYOPT(5) and KEYOPT(6) parameters provide various element printout options (see Element Solution).KEYOPT(9) = 1 is used to read initial stress data from a user subroutine. For details about these user subroutines, see the ANSYS Guide to User Programmable Features.You can include the effects of pressure load stiffness in a geometric nonlinear analysis using SOLCONTROL,INCP. Pressure load stiffness effects are included in linear eigenvalue buckling automatically. If an unsymmetric matrix is needed for pressure load stiffness effects, use NROPT,UNSYM.A summary of the element input is given in . A general description of element input is given in Element Input.PLANE82 Input SummaryElement Name PLANE82Nodes I, J, K, L, M, N, O, PDegrees of Freedom UX, UYReal Constants None, if KEYOPT (3) = 0, 1, 2Thickness, if KEYOPT (3) = 3Material Properties EX, EY, EZ, (PRXY, PRYZ, PRXZ or NUXY, NUYZ, NUXZ),ALPX, ALPY, ALPZ, DENS, GXY, DAMPSurface Loads Pressures- face 1 (J-I), face 2 (K-J), face 3 (I-K), face 4 (I-L)Body Loads Temperatures- T (I), T(J), T(K), T(L), T(M), T(N), T(O), T(P)Fluences- FL(I), F L(J), FL (K), FL(L), FL(M), FL(N), FL(O), FL(P)Special Features Plasticity, Creep, Swelling, Stress stiffening, Large deflection, Large strain, Birth and death, Adaptive descent.KEYOPT(3) 0- Plane stress1- Axisymmetric2- Plane strain (Z strain = 0.0)3- Plane stress with thickness (TK) real constant inputKEYOPT(5) 0- Basic element solution1- Repeat basic solution for all integration points2- Nodal Stress SolutionKEYOPT(6) 0- Basic element solution1- Surface solution for face I-J also2- Surface solution for both faces I-J and K-L also (surface solution valid for linear materials only)3- Nonlinear solution at each integration point also4- Surface solution for faces with nonzero pressureKEYOPT(9) 0- No user subroutine to provide initial stress (default)1- Read initial stress data from user subroutine USTRESS NoteSee the ANSYS Guide to User Programmable Features for user written subroutinesOutput DataThe solution output associated with the element is in two forms: nodal displacements included in the overall nodal solution additional element output as shown in Element Output DefinitionsPLANE82 Element Output DefinitionsNameDefinitionORELElement NumberYYNODESCorner nodes - I, J, K, LYYMATMaterial numberYYTHICKAverage thicknessYYVOLU:VolumeYYXC, YCLocation where results are reportedY3PRESPressures P1 at nodes J,I; P2 at K,J; P3 at L,K; P4 at I,LYYTEMPTemperatures T(I), T(J), T(K), T(L), T(M), T(N), T(O), T(P)YYFLUENFluences FL(I), FL(J), FL(K), FL(L), FL(M), FL(N), FL(O), FL(P)YYS: X, Y, Z, XYStresses (SZ = 0.0 for plane stress elements)YYS: 1, 2, 3Principal stressesY-S: INTStress intensityY-S: EQVEquivalent stressYYEPEL: X, Y, Z, XYElastic strainsYYEPEL: 1, 2, 3Principal elastic strainsY-EPEL: EQVEquivalent elastic strain 4-YEPTH: X, Y, Z, XYAverage thermal strainsYYEPTH: EQVEquivalent thermal strain 4-YEPPL: X, Y, XY, ZAverage plastic strains22EPPL: EQVEquivalent plastic strain 4-2EPCR: X, Y, XY, ZAverage creep strains22EPCR: EQVEquivalent creep strain 4-2EPSW:Swelling strain22NL: EPEQEquivalent plastic strain22NL: SRATRatio of trial stress to stress on yield surface22NL: SEPLEquivalent stress on stress-strain curve22NL: HPRESHydrostatic pressure-2FACEFace label11EPEL(PAR,PER,Z)Surface elastic strains (parallel, perpendicular, Z or hoop)11TEMPSurface average temperature11S(PAR,PER,Z)Surface stresses (parallel, perpendicular, Z or hoop)11SINTSurface stress intensity11SEQVSurface equivalent stress11LOCI: X, Y, ZIntegration point locations-Y1. Surface output (if KEYOPT(6) is 1, 2 or 4)2. Nonlinear solution (if the element has a nonlinear material)3. Available only at centroid as a *GET item.4. The equivalent strains use an effective Poissons ratio: for elastic and thermal this value is set by the user (MP,PRXY); for plastic and creep this value is set at 0.5.Assumptions and RestrictionsThe area of the element must be positive. The element must lie in a global X-Y plane as shown in PLANE82 and the Y-axis must be the axis of symmetry for axisymmetric analyses. An axisymmetric structure should be modeled in the +X quadrants. A face with a removed midside node implies that the displacement varies linearly, rather than parabolically, along that face. See Quadratic Elements (Midside Nodes) in the ANSYS Modeling and Meshing Guide for more information about the use of midside nodes.Product RestrictionsWhen used in the product(s) listed below, the stated product-specific restrictions apply to this element in addition to the general assumptions and restrictions given in the previous section.ANSYS/Professional. The DAMP material property is not allowed. Fluence body loads are not applicable. The only special feature allowed is stress stiffening. KEYOPT(6) = 3 is not applicable.PLANE82 2 维 8 节点结构实体单元单元说明 PLANE82 是 2 维 4 节点单元 (PLANE42) 的高阶版本。对于四边形和三角形混合网格，它有较高的结果精度；可以适应不规则形状而较少损失精度。本 8 节点单元具有一致位移形状函数，能很好地适应曲线边界。本单元有8个节点，每个节点有 2 个自由度，分别为 x 和 y 方向的平移，既可用作平面单元，也可以用作轴对称单元。本单元具有塑性、蠕变、辐射膨胀、应力刚度、大变形以及大应变的能力。有多种打印输出选型可用。关于本单元的更多细节见 ANSYS 公司理论手册 中的 PLANE82。关于能承受非轴对称载荷的轴对称单元的说明见 PLANE83。PL输入数据在图 82.1: PLANE82 单元几何 中给出了本单元的几何形状，节点位置和坐标系。将节点 K, L 和 O 定义为同一节点可以形成三角形单元。类似的，但只有 6 个节点的单元是 PLANE2。除了节点外。单元输入数据还包括一个厚度 (TK) (仅对平面应力问题) 以及正交异性材料特性。正交异性材料的方向与单元坐标系方向一致，单元坐标系的方向在 坐标系 中说明。单元载荷在 节点和单元载荷 中说明。压力可以作为单元边界上的面载荷输入，如图 82.1: PLANE82 单元几何 中带圆圈数字所示。正压力指向单元内部。可以输入温度和流量作为单元节点处的体载荷。节点 I 处的温度 T(I) 默认为 TUNIF。如果不给出其它节点处的温度，则默认等于 T(I)。如果给出了所有角节点的温度，各中间节点的温度默认为其相邻角节点温度的平均值。对于任何其它的温度输入方式，未给定的温度默认为 TUNIF。对于流量的输入与此类似，只是默认值用零代替了 TUNIF。 对平面问题，除了 KEYOPT(3) = 3 的情况外，本单元如有节点力，应输入每单位厚度的力值；对轴对称问题应输入整个圆周 (360) 的力值。KEYOPT(5) 和 KEYOPT(6) 参数提供了不同的打印输出选项 (见 单元解)。 通过 ISTRESS 或 ISFILE 命令可以对本单元施加初始应力。进一步的信息见 ANSYS 基本分析指南 中的初始应力载荷。另外，将 KEYOPT(9) 设置为 1，可以通过用户子程序 USTRESS 来读取初始应力。关于用户子程序的细节见 ANSYS 用户程序特性指南。 在进行几何非线性分析时，可以使用 SOLCONTROL,INCP 命令来包含压力载荷刚度的影响。在线性特征值屈曲分析中自动包括压力载荷刚度效应。如果需要非对称的压力载荷刚度效应矩阵，使用 NROPT,UNSYM 命令。 在 PLANE82 输入汇总 中给出了本单元输入数据的一个汇总。在 单元输入 中给出了本单元输入数据的一般说明。对于轴对称问题，见 轴对称单元。PLANE82 输入汇总 节点：I, J, K, L, M, N, O, P 自由度 UX, UY 实常数 如果 KEYOPT(3) = 0, 1, 或 2 - 无 如果 KEYOPT(3) = 3 - 输入厚度 THK 材料特性EX, EY, EZ, PRXY, PRYZ, PRXZ (或 NUXY, NUYZ, NUXZ), ALPX, ALPY, ALPZ (或CTEX, CTEY, CTEZ或THSX, THSY, THSZ), DENS, GXY,DAMP 面载荷 压力 - 边 1 (J-I), 边 2 (K-J), 边 3 (I-K), 边 4 (I-L) 体载荷 温度 T(I), T(J), T(K), T(L), T(M), T(N), T(O), T(P) 流量 FL(I), FL(J), FL(K), FL(L), FL(M), FL(N), FL(O), FL(P)特殊特征 塑性、蠕变、辐射膨胀、应力刚度、大变形、大应变、生死单元、自适应下降、初应力输入KEYOPT(3) - 单元行为: 0 - 平面应力 1 - 轴对称 2 - 平面应变 (Z 向应变 = 0.0) 3 - 带有厚度实常数 (TK) 输入的平面应力 KEYOPT(5) - 额外单元输出0 - 输出基本单元解 1 - 输出各积分点的基本单元解 2 - 输出节点应力 KEYOPT(6) - 额外表面结果输出 0 - 输出基本单元解1 同时输出 I-J 边的表面解2- 同时输出 I-J 边和 K-L 边的表面解 (仅对线性材料有效)3 - 同时输出各积分点处的非线性结果 4 - 对有非零压力的各边输出表面结果KEYOPT(9) - 初应力子程序选项 (只有直接输入 KEYOPT 命令才可用) 0 - 不使用用户子程序提供初应力 (默认)1 - 从用户子程序 USTRESS 读入初应力数据 (如何写用户子程序见 ANSYS 用户程序特性指南)PLANE82 输出数据与单元有关的结果输出有两种形式：包括在整个节点解中的节点位移。附加的单元输出，见表 82.1 PLANE82 单元输出定义。PLANE82 单元输出定义名称定 义OREL单元号YYNODES角节点 - I, J, K, LYYMAT材料号YYTHICK平均厚度YYVOLU:体积YYXC,YC结果输出点位置Y3PRES压力，P1 在节点 J,I；P2 在 K,J；P3 在 L,K； P4 at I,LYYTEMP温度 T(I), T(J), T