复合材料层合板分析ppt课件

1、WS-1WORKSHOP Define a Composite MaterialNAS121, Workshop , May 6, 2019WS-2NAS121, Workshop , May 6, 2002nProblem DescriptionnA 1 in. x 1 in. composite plate is loaded with 2000 #/in. in the Y direction on the top edge, 1000 #/in. in both the X direction and Y direction on the right hand side edge.nT

2、he left side reacts the loads with X, Y, Z, and Ry constraints.WS-3NAS121, Workshop , May 6, 2002nProblem DescriptionnThe layup is made of graphite/epoxy tape and is shown to the right.nThe angles shown are relative to the global axis shown.nThus, the 0 degree ply 1 has its fibers coming out of the

3、page in the Y direction.nNote that while the positive sense of the angles are right hand rule around the Z global axis in this layup definition, in the Nastran definition, it is around the Z element axis and thus dependent on the element GRID order.WS-4NAS121, Workshop , May 6, 2002nProblem Descript

4、ion (cont.)nThe composite plies are graphite/epoxy tape with a thickness of 0.0054 in.nThe elastic and strength properties are shown on the right.nThe failure theorem to be used is Hill.E1120e6E222e6U12.35G121e6G131e6G231e6Xt120 ksiXc110 ksiYt13 ksiYc16 ksiS14 ksiSb5 ksiWS-5NAS121, Workshop , May 6,

5、 2002nSuggested Exercise StepsnCreate a geometry model.nUse mesh seeds to define the mesh density.nCreate a finite element mesh. nApply boundary conditions to the model.nApply loads to the model.nDefine ply material properties. nCheck element normalsnDefine composite material properties.nDefine a ma

6、terial coordinate systemnApply the material coordinate system to the elements.nSubmit the model to MSC.Nastran for analysis.nAttach xdb Results FilenDisplay ply stresses using MSC.Patran. nView ply failure indices in MSC.NastrannChange layup to make failure indices below 1.0.nAnalyze the model with

7、the new composite layupnView the changed ply failure indicesWS-6NAS121, Workshop , May 6, 2002CREATE NEW DATABASECreate a new database called composite1.db:In File select NewEnter composite1 as the file nameClick OKChoose Default ToleranceSelect MSC.Nastran as the Analysis CodeSelect Structural as t

8、he Analysis TypeClick OK abcdefgWS-7NAS121, Workshop , May 6, 2002Step 1. Create a geometry modelIn Geometry create the first curve.Select Create / Surface / VertexOn the Surface Vertex “n Lists enter 0 0 0, 1 0 0, 1 1 0, 0 1 0Click ApplyClick the Show Label iconabcdWS-8NAS121, Workshop , May 6, 200

9、2Step 2. Use mesh seeds to define the mesh densityIn Elements, create mesh seeds. Select Create / Mesh Seed / UniformClick on the top edge of the plate to create a mesh seedThen click on the right edgeabcWS-9NAS121, Workshop , May 6, 2002Step 3. Create a finite element meshIn the Elements menu creat

10、e surface mesh based on the mesh seeds assigned in the previous steps. Select Create / Mesh / SurfaceSelect Quad as the Elem ShapeClick on surface 1Click ApplyabcdWS-10NAS121, Workshop , May 6, 2002Step 4. Apply boundary conditions to the modelabcdegfIn Loads/BCsSelect Create / Displacement / NodalF

11、or New Set Name enter “constraintsIn Input Data, enter for Translations, for Rotations then OKOn the top menu click on the Curve or Edge iconIn Select Application Region click lefthand edge of the surfaceClick Add and OKClick ApplyWS-11NAS121, Workshop , May 6, 2002Step 5. Apply loads to the model O

12、n the top menu click Reset GraphicsSelect Create / Distributed Loads / Element UniformEnter “Dist. Load Y for New Set NameIn Input Data, Enter for Edge Distr Load , then OKIn Select Application Region, click on the top curve of the surfaceClick Add then OKClick ApplybcdegfaWS-12NAS121, Workshop , Ma

13、y 6, 2002Step 5a. Apply loads to the model (cont.) In a similar way create Dist. Load X:Enter “Dist. Load X for New Set Name.In Input Data, Enter , then OKIn Select Application Region, click on the right hand side curve of the surface, then Add, then OK.Click Applyabc And then create Dist. Load XY:E

14、nter “Dist. Load XY for New Set Name.In Input Data, Enter , then OKIn Select Application Region, again click on the right hand side curve of the surface, then Add, then OK.Click ApplyNote that since the same edge was picked, the loads are combineddeWS-13NAS121, Workshop , May 6, 2002Step 6. Define p

15、ly material properties Go to Material menuSelect Create / 2d Orthotropic / Manual InputFor Material Name enter “graphite-epoxy_tapeClick Input Properties, Select Linear Elastic, enter 20e6, 2e6, .35, 1e6, 1e6, 1e6Click OKClick ApplyClick Input Properties again, Select Failure / Stress / Hill and ent

16、er 120e3, 13e3, 110e3, 16e3, 13e3, 5000.Click OK Click Apply againabcdefghWS-14NAS121, Workshop , May 6, 2002Step 7. Check Element NormalsCheck element normals to determine the location of ply 1.Select the Element menu:At the top menu click Reset GraphicsAt the top menu click Hide LabelsSelect Verif

17、y / Element / Normals Click Draw Normal VectorsClick ApplyabcdeWS-15NAS121, Workshop , May 6, 2002Step 8. Define composite material properties Go to Materials:Select Create/ Composite/ LaminateAt Material Name enter 8_ply_symmetric_quasiClick tape property name (graphite-epoxy_tape) slowly 8 times t

18、o make 8 pliesAt Thickness for all layers enter .0054Click on ply 1s empty Orientation cellEnter the following into the Insert Orientations box: 0 -45 45 90 90 45 -45 0 . Note that the +-45 degree plies have changed sign due to the element Z axis being in the opposite direction to the global Z axis.

19、Click Load Text Into SpreadsheetClick ApplyabcdehfgWS-16NAS121, Workshop , May 6, 2002Step 9. Define a material coordinate system Go to Geometry:Select Create / Coord / 3PointEnter Coord ID (99 in this case) you want at Coord ID listAt Origin enter 0 0 0At Point on Axis 3 enter 0 0 1At Point on Plan

20、e 1-3 enter 0 1 0Click ApplyabcdefWS-17NAS121, Workshop , May 6, 2002Step 10. Apply the material coordinate system to the elements Go to Properties:Select Create / 2D / ShellEnter “composite1 at Property Set NameAt Options select LaminateIn Input Properties click on the composite material name (8_pl

21、y_symmetric_quasi)At Material Orientation select CID and then click the material coordinate system 99 on the screenClick OKClick Application Region and click on Surface 1Click AddClick ApplyabdefghcgWS-18NAS121, Workshop , May 6, 2002Step 11. Submit the model to MSC.Nastran for analysis Go to Analys

22、is:Select Analyze / Entire Model / Full RunClick SubcasesAt Available Subcases click DefaultClick Output RequestsAt Form Type select AdvancedAt Output Requests, click twice STRESS(SORT1,REAL,VONMISES,BINLIN)=ALL;PARAM,NOCOMPS,-1At Composite Plate Opt: select Ply Stresses. Note that PARAM, NOCOMPS,-1

23、 has now changed to 1.Click OKClick Apply at Subcases and then CancelAnd click Apply at the Analyze menuabcefghijdWS-19NAS121, Workshop , May 6, 2002Step 12. Attach xdb Results File Go to Analysis:Select Attach XDB / Result Entities / LocalClick Select Results FileUse the Select File tool to find yo

24、ur xdb file in your local Patran directory and click it, in this case, “composite1.xdbClick OKClick ApplyabcdeWS-20NAS121, Workshop , May 6, 2002Step 13. Display ply stresses using MSC.PatranTo display the ply 8s 1 direction stresses: go to the Results menu:First turn off the geometry in Plot/Erase

25、Geometry EraseSelect Create / Quick PlotClick Stress TensorClick Position then select Layer 8 and click CloseClick Quantity and select X ComponentClick Displacements TranslationalClick ApplybcdefgaWS-21NAS121, Workshop , May 6, 2002 F A I L U R E I N D I C E S F O R L A Y E R E D C O M P O S I T E E

26、 L E M E N T S ( Q U A D 4 ) ELEMENT FAILURE PLY FP=FAILURE INDEX FOR PLY FB=FAILURE INDEX FOR BONDING FAILURE INDEX FOR ELEMENT FLAG ID THEORY ID (DIRECT STRESSES/STRAINS) (INTER-LAMINAR STRESSES) MAX OF FP,FB FOR ALL PLIES 1 HILL 1 6.1711 0.0000 2 7.7170 0.0000 3 6.4169 0.0000 4 7.3154 0.0000 5 7.

27、3154 0.0000 6 6.4169 0.0000 7 7.7170 0.0000 8 6.1711 7.7170 * . Step 14. View ply failure indices in MSC.Nastran To view the failure indices, open the composite1.f06 file in an editor and search for the following section. It is organized as follows:Element numberPly numberPly failure indexPly interl

28、aminar failure indexHighest failure index in elementFlag if highest failure index is greater than 1.0 (indicating ply failure)abcdefNote that Patran does not display composite failure indices.WS-22NAS121, Workshop , May 6, 2002nHand calculationsnElement 1, ply 2, a 45 degree ply, has the highest fai

29、lure index of 7.72 but all of the plies have similar values, thus it is difficult to determine which direction to add plies. However, looking at the terms of Hills theorem may tell us:nSubstituting values: nShows that the 1 direction is the largest contributor to the failure and thus the composite n

30、eeds more -45 degree plies. nUsing this same method, it was found that a 20 ply symmetric layup will give failure indices less than 1.0. The layup is a 0 ply, 4 45 plies, 2 45 plies, and 3 90 plies and then a symmetric layup for the other 10 plies.SXYX2212221222221t92. 739. 110. 014. 029. 6313453. 1

31、3120378. 4501. 3313378. 43120501. 32222222eeeeeeeeeStep 15. Change layup to make failure indices below 1.0WS-23NAS121, Workshop , May 6, 2002Step 15a. Change layup to make failure indices below 1.0To change to a new layup: go to Materials:Select Modify / Composite / LaminateIn Laminated Comp. To Mod

32、ify click 8_ply_symmetric_quasiAt New Material Name enter 0_4x45_2x-45_3x90_symIn the Laminated Composite popup click on ply 1 and then shift click on ply 8 to select all the pliesClick on Delete Selected RowsSelect Text Entry Mode Insert. In the Modify Menu on the right, click slowly on graphite-epoxy_tape 10 times, once for each plyOn Stacking Sequence Convention select SymmetricAt Thickness For All Layers enter .0054Click on the empty ply 1 Orientation cellSelect Text Entry Mode OverwriteIn Overwrite Orientations enter 0 45 45 45 45 -45 -45 9