北航宇航学院飞设实验报告Word文档格式.docx

1、壳的内表面有分布载荷（Y轴如图3所示）。3.建模过程3.1几何模型的建立1.建立新的数据库，输入全局参数，最大尺寸为6米File/newNew database name: sylindrical shell structureOk Based on modelApproximate maximun model Dimesion: 6.0 Analysis code: MSC.Nastran Analysis type: structure Ok 2.建立名为”shell”的一个新组Group/createNew group name: shell Make current ApplyCanc

2、le 3.绘制一半径为0.5m的圆，并通过面拉伸命令形成壳体 Geometry Action creat Object curve Method 2D CircleCircle radius 0.5 Construction plane list coord 0.3 Center point list 0 0 0 Action create Object surfaceMethod extrudeTanslation vector Curve list curve 1 4.复制刚刚生成的圆柱壳体Action tranformObject surface Method translateSurf

3、ace list surface 1Direction vector Vector magnitude 3 Repeat count 1 5.建立一个新的组取名为”circular_beam” circular beams6.通过复制生成另外两个圆形梁曲线Action tranformObject circle Curve list curve 1 Direction vector Repeat count 2 7.纵向筋的绘制，建立一个名为” longitudinal beams”的新组 longitudinal beams8.沿长度方向创建一条直线Action creatObject cu

4、rveMethod pointStarding point point 1Ending point point 3 9.通过旋转的方法创建8条直线，旋转角度为45Action transformObject curve Method rotate Rotation angle 45 Repeat count 7 Curve list curve 4 图 31几何模型建立完成1.1 显示组”shell”，并设置为当前组Group/postSelect group to post: shell 3.2有限元网格划分 1.将组”shell”设置为当前组 2.生成”mesh seed” Element

5、sAction create Object mesh seedType uniform Number of elements: Number= 32 Curve list curve 1 Number= 30 Curve list surface 1.1 2.1 3. 选择”isomesh”，生成四边形单元Object meshType surfaceElem shape quadMesher IsoMeshTopology Quad4Surface list surface 1 24.显示组“longitudinal beams” 并且设置为当前组 longitudinal beams 5.

6、用curve的方式划分longitudinal beams的网格Action creatType curveTopology bar2curve list curve 4:11 6.显示组“cicular beams” 并设置为当前组 circular beams 7.用curve的方式划分circular beams的网格Object meshType curveTopology bar2curve list curve 1:3 8.节点等效在面的边上重复创建了节点，因此需要将节点等效Action: equivalence Object: allType: tolerance cubeEqu

7、ivalence tolerance: 0.004 Apply 图3-2 有限元网格划分完成3.3 材料属性添加3.3.1 复合材料的添加 1.facesheet和core材料添加 Material create 2d orthotropicMethod: manual inputMaterial name: facesheetInput propertiesConstitutive model: linear elasticElastic modulus 11: 1e11 Elastic modulus 22: 1e10 Poisson ratio 12: 0.1 Shear modulus

8、 12: 1.5e10 coreConstitutive model=: inear elasticElastic modulus 11=: 100 Elastic modulus 22=: 100 0.3 50 Shear modulus 23: 1e6 Shear modulus 13:图3-3 core材料属性图3-4 facesheet材料属性 2.复合材料属性添加，用core和facesheet材料铺成复合材料 create composite laminate compsite_layersLaminated composite Material namethichnessorie

9、ntation1facesheet 3e-4452facesheet-45core5e-345Input date 图3-5 复合材料建立完成 3.铜的材料属性添加 isotropic copper Elastic modulus= 1e11 Poission ratiao= 0.33 4.创建单元属性并将单元属性赋给壳单元 Group/post shell Properties create 2D shell Property set name: composite shell Options: lanminlate m:composite_layersSelect members: ele

10、 1:960 copper shell homogenous m:copperThickness: 2E-3 ele 961:19205.建立本地坐标圆柱系在壳的地步中心点建立一个本地圆柱坐标系，编号1，用于定义纵向L型梁的指向。 GeometryObject coord Method 3point Coord ID list 1 Type cylindricalRefer. Coordinate frame coord 1 Origin 0 0 0 Point on axis 3 0 0 1 Point on plan1-3 1 0 0 6.创建L型的单元属性并将其赋给L型梁单元 creat

11、e 1D beamProperty set name copper_beamInput properties Beam library Action create Object standard shapeMethod nastran standardNew section name L L W= 10e-3H= 10e-3t1= 3e-3 t2= 3e-3 Ok Section name L Material name m:copper Bar orientation coord 1 Select application region: ele 1921:2400 Apply Action:

12、 1D L-beamAction createNew section name rectangle W= 10e-3 Ok Section name rectangle ele 2401:2496 3.4 固定边界条件建立 Loads/BCs create displacement nodal New set name: fixed_nodeInput dataTranslation Rotations , , Analysis coordinate frame: coord 0Selet applicaytion region FEM Application region: node 1:2

13、9: Add 图3-6固定边界加载完成3.5 建立壳内表面压力场1.创建一个变化的标量场 Field create spatial pcl functionField name: linear_loadField type: scalarCoordinate system type: RealCoordinate system: coord 0 Scalar function: 200*abs（Y）Create the pressure load that will reference the field function. Loads/BCs pressure element uniform

14、 surface_load Target element type: 2D Loads/BCs set scale factor 1 Pressure:Bot surf pressure f:linear_load ele 1:图3-7 内表面加变化的压力载荷2.压力载荷和边界条件组装到名为“shell_loads”的工况里面。 Load casesLoad case name: shell_load Type static Assign/prioritize load/BCs: Disp_fixed_node Press_shell_load3.6 将建好的模型提交给Nastran分析 An

15、alysi analyze entire modle full run Job name: cylindrical_shellSolution type: linear static Subcase select Available load cases:3.7 读取并查看分析结果 Analysis access results attach XDB result entities Available jobs:Select results fileSelect results file: cylindrical_shell.XDB Results quick plot Select results cases: cylindracal_shell Select fringe result: stress tensor Quanlity: magnitude Select deformation result: displacements translational4.结果分析 各部位各层应力变形图如下图4-1 z1层图4-2 z2层图4-3 复合材料第1层图4-4 复合材料第2层图4-5 复合材料第3层图4-6 复合材料第4层图4-7 复合材料第5层