PAT325, Workshop 8B, March 2010 PAT325, Workshop 8B, March 2010
WORKSHOP 8B
WORKSHOP 8B
MODELING HONEYCOMB WITH
MODELING HONEYCOMB WITH
SOLID AND SHELL ELEMENTS
SOLID AND SHELL ELEMENTS
PAT325, Workshop 8B, March 2010
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Unlike the previous workshop that involved modeling the
honeycomb structure using the MSC.Laminate Modeler, this
workshop is used to show how to model the honeycomb
structure using solid and shell elements. Solid hexahedral
elements are to be used to represent the core, and shell
elements are to used to represent the laminate backing. Similar
constraints and loading are to be applied to the model. After the
MD.Nastran analysis the results are to be looked at, and
perhaps compared to those for the previous laminate model.
PROBLEM DESCRIPTION
1.
Create a new database
2.
Import two surfaces from an IGES File
3.
Create a solid from the two imported surfaces
4.Mesh the solid using IsoMesh
5.
Mesh surfaces of the solid using IsoMesh
6.Equivalence the solid and surface meshes
7.Cantilever one end of honeycomb model
8.
Apply the force load at the free end of the model
9.Create material properties using a session file
10.Create the isotropic material for the core
11.
Create a composite material using laminate in Patran
12.Create 3D element property for core material
13.
Create element property for upper lamina
14.Create element property for lower lamina
15.Analyze the model and attach the results file
16.
Verify the stress tensor and displacement results
SUGGESTED EXERCISE STEPS
PAT325, Workshop 8B, March 2010
Step 1. Create a New Database
a
b
f
d
c e
Create a new database. a. File / New.
b. Enter 2nd_Honeycomb as the file name.
c. Click OK.
d. Select MD.Nastran or MSC Nastran as the Analysis Code.
e. Select Structural as the Analysis Type.
Step 2. Import Two Surfaces from an IGES File
Import 2 surfaces from IGES a. File / Import
b. Select IGES from the Source.
c. Select exercise8b.igs. d. Deselect Import to
Parasolid e. Click Apply
f. Click OK when the IGES Import Summary appears.
d c a b e f
PAT325, Workshop 8B, March 2010
This is how the geometry should look like after importing the file.
Step 3. Create a Solid from the Two Imported Surfaces
Create a parametric solid using the two surfaces.
a. Geometry: Create / Solid / Surface.
b. Select 2 Surfaces as the Option.
c. Uncheck the Auto Execute toggle.
d. Select Surface 1 as the Starting Surface List. e. Select Surface 2 as the
Ending Surface List. f. Click Apply. a d f c b e
PAT325, Workshop 8B, March 2010
Step 4. Mesh the Solid Using IsoMesh
Mesh the geometric solid.
a. Elements: Create / Mesh / Solid.
b. Select Hex as the Elem Shape.
c. Select IsoMesh as the Mesher.
d. Select Hex8 as the Topology.
e. Uncheck the Automatic Calculation.
f. Enter 5.0 as the Global Edge Length Value. g. Select Solid 1 as the
Solid List. h. Click Apply. a b c d g f e h
Step 5. Mesh Surfaces of the Solid Using IsoMesh
Mesh the surfaces (at inner and outer free faces of the hex elements) with shell elements.
a. Elements: Create / Mesh / Surface. b. Select Quad as the Elem Shape. c. Select IsoMesh as the Mesher. d. Select Quad4 as the Topology.
e. Uncheck the Automatic Calculation. f. Enter 5.0 as the Value.
g. Select Surface 1 as the Surface List. h. Click Apply.
i. Select Surface 2 as the Surface List. j. Click Apply.
Note that both surfaces could have been meshed simultaneously. d c b a e g f i j h
PAT325, Workshop 8B, March 2010
Step 5. Mesh Surfaces of the Solid Using IsoMesh (Cont.)
Shell element
Step 6. Equivalence the Solid and Surface Meshes
Equivalence the solid and surface mesh nodes.
a. Elements: Equivalence / All / Tolerance Cube. b. Click Apply.
a
PAT325, Workshop 8B, March 2010
Step 7. Cantilever One End of Honeycomb Model
Fixed nodes at one end using a solid face as the application region..
a. Loads/BCs: Create / Displacement / Nodal. b. Enter Fixed_surface as
the New Set Name. c. ClickInput Data…
d. Enter < 0, 0, 0 > as the Translations.
e. Enter < 0, 0, 0 > as the Rotations.
f. Click OK.
g. Click Select Application
Region…
h. Select Surface Picking Icon.
i. Select the small lower face as the geometry entity. j. Click Add. k. Click OK. l. Click Apply. j a g c b e d i h k l f
The nodes at solid face Solid 1.1 are constrained.
PAT325, Workshop 8B, March 2010
Step 8. Apply the Force Load at the Free End of the Model
Apply loads at four points. a. Loads/BCs: Create /
Force / Nodal.
b. Enter Load as the New Set Name.
c. Click on Input Data….
d. Enter < 0.5, 0, 0 > as the Force. e. Click OK. f. Click Select Application Region… a c b f d e
a. Select Point Picking Icon.
b. Select Point 3 4 7 8 from the geometry as the Select Geometry Entities.
c. Click Add. d. Click OK.
Step 8. Apply the Force Load at the Free End of the Model (Cont.)
c
d b
PAT325, Workshop 8B, March 2010
a. Click Apply.
Now the model has been assigned a load of 0.5 at four different points, a total of 2.
Step 8. Apply the Force Load at the Free End of the Model (Cont.)
Step 9. Create Material Properties Using a Session File
Read(play) session file materials.ses.
a. File / Session / Play…
b. Select materials.ses. c. Click Apply.
a
b
PAT325, Workshop 8B, March 2010
Step 10. Create the Isotropic Material for the Core
Create a material to represent the core
a. Materials: Create / Isotropic / Manual Input. b. Enter Core as the
Material Name.
c. ClickInput Properties…
d. Select Linear Elastic as the Constitutive Model. e. Enter 215 as the Elastic
Modulus.
f. Enter 150 as the Shear Modulus. g. Click OK. h. Click Apply. d g a f e c h b
Step 11. Create a Composite Material Using Laminate in Patran
Create an inner(upper) laminate in Patran.
a. Materials: Create / Composite / Laminate. b. Enter upper_ply as the
Material Name.
c. Click ud_t300_n5208 four times to upload to the Stacking Sequence Definition. d. Click Thicknesses. e. Enter 4(0.12) in the Overwrite Thickness. f. Press Enter. g. Click Orientations. h. Enter -45 / 90 / 45 / 0 in the Insert Orientations. i. Press Enter. j. Click Apply. c a b j d g e h f i
PAT325, Workshop 8B, March 2010
a. Enter lower_ply as the Material Name.
b. Click Delete Selected Rows many times so that the Stacking Sequence Definition becomes empty. c. Select ud_t300_n5208 four
times as the Material. d. Click Thickness. e. Enter 4(0.12) in the
Overwrite Thicknesses text box.
f. Press Enter. g. Click Orientation.
h. Enter 0 / 45 / 90 / -45 in the Overwrite Orientations text box.
i. Press Enter.
j. Set the Offset to –0.48. k. Click Apply.
Step 11. Create a Composite Material in Patran (Cont.)
j b c a k i f g d h e
Step 12. Create 3D Element Property for Core Material
Create element properties for 3D solid core.
a. Properties: Create / 3D / Solid.
b. Enter 3D_Solid as the Property Set Name. c. Select Standard
Formulation as the Options.
d. Click Input
Properties…
e. Click Select Material. f. Select Core from
Existing Material. g. Click OK.
h. Click Select
Application Region…
i. Select Solid 1 for the Select Members. j. Click Add. k. Click OK. l. Click Apply. a b c d h l f e g j i k
PAT325, Workshop 8B, March 2010
Step 13. Create Element Property for Upper Lamina
Create 2D element properties for plies above the core. a. Properties: Create / 2D
/ Shell
b. Enter 2D_upper_shell for Property Name. c. Select Thin, Laminate
and Standard Formulation under Options. d. Click Input Properties… e. Select upper_ply. f. Enter Coord 0 on Material Orientation g. Click OK. h. Click Select Application Region. i. Select Surface 1 under
Select Members. j. Click Add. k. Click OK. l. Click Apply. a i h k d e j f g c b l
Create 2D element properties for plies below the core.
a. Properties: Create / 2D / Shell
b. Enter 2D_bottom_shell as the Property Set Name. c. Select Thin, Laminate and
Standard Formulation under Options.
d. Click Input Properties…
e. Select lower_ply as the Material Name.
f. Enter Coord 0 on Material Orientation
g. Click OK.
h. Click Select Application Region.
i. Select Surface 2 for the Select Members.
j. Click Add. k. Click OK. l. Click Apply.
Step 14. Create Element Property for Lower Lamina
e a i h k d j f g c b l
PAT325, Workshop 8B, March 2010
Step 15. Analyze the Model and Attach the Results File
Run the analysis and attach the results file.
a. Analysis: Analyze / Entire Model / Full Run. b. Click Apply.
c. Analysis: Access Results / Attach XDB / Result Entities.
d. Click Select Results
File… e. Select 2nd _Honeycomb. f. Click OK. g. Click Apply. a d g b c f e
Step 16. Verify the Stress Tensor and Displacement Results
Check the deformation results. a. Results: Create / Quick
Plot.
b. Select Default,
A1:Static Subcase from the Select Result Cases. c. Select Stress Tensor as the Select Fringe Result. d. Select Layer 1, or some
other layer. e. Select Displacement, Translational as the Select Deformation Result. f. Click Apply. d f e c b a Comparing WS8A vs WS8B Maximum Displacement WS8A 0.0182 WS8B 0.0328
