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WORKSHOP 12
RBE2 vs. RBE3
WS12-2NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
WS12-3NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Workshop ObjectivesPractice constructing RBE2 and RBE3 in Patran.
Understand the difference between RBE2 and RBE3.
WS12-4NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Problem DescriptionA rectangular plate is fixed at its left and right edges. A rigid body element is in the middle of the plate. Model this two waysin one database using RBE2 and RBE3 elements.E = 10 x 106 psi ν =0.33t = 0.2 in
WS12-5NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Suggested Exercise Steps1. Create a new database and name it rbe2_vs_rbe3.db. 2. Create four rectangular surfaces.3. Mesh the surfaces to create plate elements. 4. Create two additional nodes.5. Create an RBE2 MPC. 6. Create an RBE3 MPC.7. Apply Loads and Boundary Conditions.8. Create material properties. 9. Create physical properties.10. Run analysis with MSC.Nastran.11. Read the results into MSC.Patran.12. Plot the Von Mises stress and displacement. 13. Create vector marker plots to compare the RBE2 and RBE3 elements.
WS12-6NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
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Step 1. Create New Database
Create a new database called rbe2_vs_rbe3.db
a. File / New.b. Enter rbe2_vs_rbe3 as
the file name.c. Click OK.d. Choose Default
Tolerance.e. Select MSC.Nastran as
the Analysis Code.f. Select Structural as the
Analysis Type. g. Click OK.
a
e
WS12-7NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 2. Create Rectangular Surfaces
Create a surfacea. Geometry: Create /
Surface / XYZ.b. Enter <10 10 0> for
the Vector Coordinates List.
c. Enter [0 0 0] [0 15 0] [20 0 0] [20 15 0] for the Origin Coordinates List.
d. Click Apply. b
d
a
c
WS12-8NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 3. Mesh the Surfaces
Create a surface mesha. Elements: Create / Mesh
/ Surface.b. Select the surfaces.c. Enter 2.5 for the Global
Edge Length.d. Click Apply.
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c
d
WS12-9NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 4. Create Two Nodes
Create two nodesa. Elements: Create / Node
/ Edit.b. Enter 1000 for the Node
ID.c. Enter [15 5 0] for the
Node Location List.d. Click Apply.e. Repeat the procedure
with 2000 as the Node ID and [15 20 0] as the Node Location.
f. Click on the Node SizeIcon
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WS12-10NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 5. Create RBE2
Define dependent nodes.a. Elements: Create / MPC
/ RBE2.b. Enter 1000 for the MPC
ID.c. Click on Define Terms.d. Disable Auto Execute.e. Select the nodes on the
lower inner edges, as shown.
f. Select all six degrees of freedom in the DOFslist.
g. Click Apply.
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WS12-11NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 5. Create RBE2
Define independent nodesa. Select Node 1000 in
the Node List box.b. Click Apply.c. Click Cancel.d. Click Apply in the
Finite Elements form.
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b c
d
WS12-12NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 6. Create RBE3
Define dependent nodes.a. Elements: Create /
MPC / RBE3.b. Enter 2000 for the
MPC ID.c. Click on Define
Terms.d. Select Node 2000 in
the Node List box.e. Select all six degrees
of freedom in the DOFs list.
f. Click Apply.
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WS12-13NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 6. Create RBE3
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Define independent nodesa. Click on Create
Independent.b. Select the nodes on
the upper inner edges, as shown.
c. Select UX, UY, and UZ in the DOFs list.
d. Click Apply.e. Click Cancel.
a
WS12-14NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 6. Create RBE3
Finish creating RBE3a. Elements: Create /
MPC / RBE3.b. Click Apply.
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b
WS12-15NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 7. Apply Loads and Boundary Conditions
Create a boundary conditiona. Loads/BCs: Create /
Displacement / Nodal.b. Enter fixed as the New Set
Name.c. Click Input Data.d. Enter <0 0 0> for
Translations and Rotations. e. Click OK.
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c
d
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a
WS12-16NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Apply the boundary conditiona. Click Select
Application Region.b. For the Geometry
Filter select Geometry.
c. Set the Selection Filter to Curve or Edge and select an outer edge, as shown.
d. Click Add.e. Repeat the procedure
until all four edges have been added.
f. Click OK. g. Click Apply.
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Step 7. Apply Loads and Boundary Conditions
c
WS12-17NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 7. Apply Loads and Boundary Conditions
Create a loada. Loads/BCs: Create / Force
/ Nodal.b. Enter point_load as the
New Set Name.c. Click Input Data.d. Enter <100 0 0> for Force. e. Click OK.
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WS12-18NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Apply the loada. Click Select
Application Region.b. For the Geometry
Filter select FEM.c. Select Nodes 1000
and 2000.d. Click Add.e. Click OK. f. Click Apply.
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Step 7. Apply Loads and Boundary Conditions
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WS12-19NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 8. Create Material Properties
Create an isotropic materiala. Materials: Create / Isotropic
/ Manual Input.b. Enter aluminum for the
Material Name.c. Click Input Properties.d. Enter 10e6 for the Elastic
Modulus.e. Enter 0.33 for the Poisson
Ratio.f. Click OK. g. Click Apply.
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c
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WS12-20NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 9. Create Physical Properties
Create physical propertiesa. Properties: Create / 2D /
Shell.b. Enter plate as the Property
Set Name.c. Click Input Properties.d. Click on the Select
Material Icon.e. Select aluminum as the
material.f. Enter 0.2 for the Thickness.g. Click OK.
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WS12-21NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Apply the physical propertiesa. Click in the Select
Members box.b. Rectangular pick all
surfaces as shown.c. Click Add.d. Click Apply.
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Step 9. Create Physical Properties
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WS12-22NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 10. Run Linear Static Analysis
Analyze the modela. Analysis: Analyze /
Entire Model / Full Run.
b. Click Subcases.c. Choose Default from
Available Subcases.d. Click Output
Requests.e. Select Multi Point
Constant Forces.f. Click OK.g. Click Apply. h. Click Cancel.i. Click Apply.
hgf
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WS12-23NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 11. Read Results into MSC.Patran
Attach the results filea. Analysis: Access Results /
Attach XDB / Result Entities.
b. Click Select Results File.c. Choose the results file
rbe2_vs_rbe3.xdb.d. Click OK. e. Click Apply.
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WS12-24NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 12. Plot Stress and Displacement
Create a quick plota. Results: Create / Quick
Plot.b. Select Stress Tensor as
the Fringe Result.c. Select Displacements,
Translational as the Deformation Result.
d. Click Apply.
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WS12-25NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 13. Plot Vector Markers
Create a marker plota. Click on Reset Graphicsb. Results: Create / Marker /
Vector.c. Select MPC Constant
Forces, Translational as the Vector Result.
d. Select Show As Resultant.
e. Click Apply.
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WS12-26NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 13. Plot Vector Markers
Create a marker plota. Results: Create / Marker /
Vector.b. Click Reset Graphics.c. Select MPC Constant
Forces, Translational as the Vector Result.
d. Select Show As Component.
e. Select only XX as the Component.
f. Click Apply.
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WS12-27NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation
Step 13. Plot Vector Markers
Create a marker plota. Results: Create / Marker /
Vector.b. Select MPC Constant
Forces, Translational as the Vector Result.
c. Select Show As Component.
d. Select YY as the component.
e. Click Apply.
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WS12-28NAS120, Workshop 12, May 2006Copyright© 2005 MSC.Software Corporation