ws08b_honeycombsolid

WS8B-1PAT325, Workshop 8B, March 2010Copyright 2010 MSC.Software Corporation

WORKSHOP 8BMODELING HONEYCOMB WITH SOLID AND SHELL ELEMENTS


● 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


Step 1. Create a New Database

a

b

f

d

ce

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.

f. Click OK.


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

ab

e

f


This is how the geometry should look like after importing the file.

Step 2. Import Two Surfaces from an IGES File (Cont.)


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


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

bc

d

g

fe

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

jh


Step 5. Mesh Surfaces of the Solid Using IsoMesh (Cont.)

Shell element

Solid 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

b


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. Click Input 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

kl

f


The nodes at solid face Solid 1.1 are constrained.

Step 7. Cantilever One End of Honeycomb Model (Cont.)


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

a


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.)

a


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

c


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. Click Input 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 ge h

f i


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

if

gdhe


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

fe

gj

i

k


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.


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

hk

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.


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

hk

d

j

f

g

c

b

l


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

gb

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

MaximumDisplacement

WS8A 0.0182

WS8B 0.0328

ws08b_honeycombsolid

Documents

stacking sequence

click input

create element

software corporation

surface list

standard formulation

stress tensor

select surface