NAS120 WS14 Parasolid Modeling

8/7/2019 NAS120 WS14 Parasolid Modeling

1/34

WORKSHOP 15

PARASOLID MODELING


2/34

WS15-2

NAS120, Workshop 15, May 2006

Copyright 2005 MSC.Software Corporation


3/34

WS15-3



Workshop Objectives Create a parasolid model of a tension fitting using a number of the

parasolid tools in MSC.Patran


4/34

WS15-4



Suggested Exercise Steps1. Create a new database for the tension fitting model.

2. Create all the necessary 2D Geometry.

3. Extrude the surface to begin creating the solid model.

4. Create a solid shell by removing part of the solid.

5. Create fillets for all inside edges of the solid.

6. Create holes for the model by creating solid cylinders that pass through it,and then use boolean to subtract the cylinders.

7. Create cylinders to imprint the model.

8. Imprint the solid using the cylinders.

9. Delete the cylinders used for imprinting.10. TetMesh the completed solid

11. Create loads and constraints on the model that will be used in the analysis.

12. Create material properties for the model.

13. Create the 3D element properties.14. Check to see that the load case Default has the load and constraint.

15. Run the analysis by sending the model to MSC.Nastran.

16. Access the results by attaching the XDB file.

17. Post-process the results from MSC.Nastran.


5/34

WS15-5



Step 1. Create New Database for Tension Fitting

Create a new database called

tension_fitting.db.

a. File / New.

b. Entertension_fitting asthe file name.

c. Click OK.

d. Choose Tolerance

Based on Model.

e. Select MSC.Nastran as

the Analysis Code.f. Select Structural as the

Analysis Type.

g. Click OK.

a

b c

d

e

f

g


6/34

WS15-6



Step 2. Create Surface

Create the Geometry for the

tension fitting.

a. Geometry: Create /Surface / XYZ.

b. Enter forVector

Coordinates List.

c. Enter[0 0 0] forOrigin

Coordinates List.

d. Click Apply.

a

b

c

d


7/34

WS15-7



Step 2. Create Surface (Cont.)

Copy points at opposite corners.

a. Click increase Point Size

icon to show all points

enlarged.

b. Geometry: Transform /

Point / Translate.

c. Enter for

Direction Vector.

d. Click in the Point List box.

e. Click on the top-left

corner.

f. Enter for

Translation Vector.

g. Click in the Point List box.

h. Click on the bottom-rightcorner.

a

e

h

b

c f

dg


8/34

WS15-8




Create a curve by connecting

the two translated points.

a. Geometry: Create /

Curve / Point.b. Click on one of the two

translated points as the

starting point and the

other as the ending

point.

a

b

b

S 2 C S f (C )


9/34

WS15-9




Break the surface with the

sloped curve.

a. Geometry: Edit /

Surface / Break.b. Select the rectangular

surface for the

Surface List and the

sloped curve for the

Break Curve List.

c. ClickYes whenmessage box appears.

d. Click the Refresh

Graphics icon.

a

b

c

d

St 2 C t S f (C t )


10/34

WS15-10




Delete the upper surface

(above the break curve).

a. Geometry: Delete /Surface.

b. Click on the triangular

surface for the

Surface List.

c. Click Apply.

a

b

c

St 3 E t d th S f t C t S lid


11/34

WS15-11



Create a parasolid solid

by extruding the surface

in the z-direction.

a. Geometry: Create/ Solid / Extrude.

b. Make sure

TetMeshable solid

icon is selected.

c. Enter for

the Translation

Vector.

d. Click in the

surface list box

and then click on

the surface.

e. Click Iso1 view.

f. Click the Smooth-

shaded icon.

Step 3. Extrude the Surface to Create Solid

a

b

d

ef

c

Step 4 Create a solid shell


12/34

WS15-12



Step 4. Create a solid shell

Edit the solid using the shell method to

create a shelled solid.

a. Geometry: Edit / Solid / Shell

b. Enter0.25 forThickness and

turn off Auto Execute.

c. Click on Solid Face List and

hold down the shift key and

select the top, sloped, and front

faces of the solid.d. Click Apply.

a

b

d

c

c

Step 5 Create Fillets


13/34

WS15-13



Step 5. Create Fillets

Create the fillets on the inner edges

of the solid.

a. Geometry: Edit / Solid /Edge Blend.

b. Make sure that the constant

radius icon is selected.

c. Enter0.25 forConstant

Radius.

d. Make sure Edges of Solidicon is selected.

e. Click on Solid Edge List

and screen pick the two

edges on the inside bottom

of the solid.

f. Screen pick the inside rear

edge of the solid, as shown.

(Patran will automatically

blend the two remaining

inner edges.)

a

b

c

d

e

f

e

It may be necessary

to rotate the object in

order to see theninner edges more

easily. This can be

done by holding the

middle mouse button

and moving the

mouse.

Step 6 Create Holes for the Tension Fitting


14/34

WS15-14



Step 6. Create Holes for the Tension Fitting

Create the holes for the tension fitting

by creating primitive solids that pass

through the solid, then subtracting

them.

a. Geometry: Create / Solid /

Primitive.

b. Select the cylinder icon

c. Enter2.0 for the Height and

0.25 for the radius.

d. Enter[-1 1.25 1] for the Base

Center Point List and Coord

0.1 for the Axis List.

e. Click Apply.

f. Geometry : Edit / Solid /

Boolean.

g. Select Subtract icon.

h. Select the tension fitting for

the Target Solid.

i. Select the cylinder for the

Subtracting Solid List.

a

b

c

d

e

f

g

h

i

Step 6 Create Holes for the Tension Fitting (Cont )


15/34

WS15-15



Step 6. Create Holes for the Tension Fitting (Cont.)

Create the points where the

three bottom holes will be placed

by translating an existing point

and, then translating again.

a. Click Wireframe icon.b. Geometry: Create / Point /

Extract.

c. Select the Curve Icon.

d. Click in the curve list box

and select the curve as

shown.e. Geometry: Transform /

Point / Translate.

f. Enter for

Direction Vector.

g. Click in the point list box

and select the new point.h. Enter for

Direction Vector.

i. Enter2 forrepeat count.

j. Select the translated

point.

a

b

c

d

h

i

e

f

g

j

j

Step 6 Create Holes for the Tension Fitting (Cont )


16/34

WS15-16



Step 6. Create Holes for the Tension Fitting (Cont.)

Create cylinders and then holes by

subtracting them from the solid.

a. Geometry: Create / Solid /

Primitive.

b. Select cylinder icon.

c. Enter -1.0 forHeight List and

0.125 forRadius List.

d. Turn off Auto Execute.

e. Shift-click to select the three

translated points forBase

Center Point List.

f. EnterCoord 0.2 for axis list

and click Apply.

g. Click Smooth Shaded icon.

h. Geometry: Edit / Solid /

Boolean.

i. Select subtract icon and turn offAuto Execute.

j. Select tension fitting as Target

Solid.

k. Shift-click all three cylinders for

Subtracting Solid List.

l. Click Apply.

It may be

necessary to rotate

the object several

times in order to

select the cylinderswith ease

a

b

c

e

f

h

i

jj

l

k

d

g

Step 7 Create Cylinder to Imprint Tension Fitting


17/34

WS15-17



Step 7. Create Cylinder to Imprint Tension Fitting

Create a point in the center of

the large hole in order to create

a cylinder to imprint onto the

solid. Then create the cylinder

that will be used for imprinting.

a. Click Wireframe icon.

b. Geometry: Create / Point

/ ArcCenter.

c. Select the hole edge.

d. Geometry: Create / Solid /

Primitive.

e. Select cylinder icon

f. Enter1.0 forHeight and

0.371 forRadius.

g. Click on point in the

center of the big hole.h. EnterCoord 0.1 forAxis

List.

i. Click Apply.

j. Click Smooth Shaded

icon.

a

b

c

c

g

d

f

g

hi

e

j

Step 8. Imprint the Solid


18/34

WS15-18



Step 8. Imprint the Solid

Use the cylinder to imprint

the solid and then delete

the cylinder, resulting in the

finished solid.a. Geometry: Edit /

Solid / Imprint.

b. Select the tension

fitting for the Solid

List (A).

c. Select the cylinderfor the Solid to

Imprint List (B).

The solid may

seem unchanged,

but the imprint on

the solid will not be

visible until the the

cylinder has been

deleted.

a

c

b

Step 9. Delete the Cylinders


19/34

WS15-19



Step 9. Delete the Cylinders

Delete the cylinder and make

sure imprint method was

completed.

a. Geometry: Delete / Solid

b. Select the cylinder for

Solid List.

c. Click Apply.

a

b

c

Step 10. TetMesh the Completed Solid


20/34

WS15-20



p p

Create the TetMesh for the

tension fitting.

a. Elements : Create /

Mesh / Solid.

b. Make sure Tet,

TetMesh, and Tet10

are all selected.

c. Click on Input List

and select the solid.

d. Remove check for

AutomaticCalculation and enter

0.25 forGlobal Edge

Length.

e. Click Apply.

a

b

c

d

e

Step 11. Create Loads and Constraints


21/34

WS15-21



p

Create the loads and constraints

for the model.

a. Click Refresh Graphics

icon

b. Loads/BCs: Create / Total

Load / Element Uniform.

c. EnterForce as the New

Set Name.

d. Click Input Data

e. Enter for theLoad and click OK.

f. Click Select Application

Region

g. Select the annular face

created by imprinting at

the larger hole, then click

Add.

h. Click OK

i. Click Apply.

a

e

g

h

Illustrated here is the

desired application

region.g

b

c

d

fi

Step 11. Create Loads and Constraints (Cont.)


22/34

WS15-22



p ( )



23/34

WS15-23



Create the constraints on the base

holes.

a. Loads/BCs: Create /

Displacement / Nodal.

b. EnterFixed as New Set

Name.

c. Click Input Data

d. Enter forTranslation

only, and click OK.

e. Click Select Application

Region.

f. Click on Select Geometry

Entities.

g. Select Surface or Face icon

h. Shift-click the cylindricalsurfaces at the three holes on

the base, and Click Add.

i. Click OK.

j. Click Apply.

d

f

g

h

i

hIllustrated here is the

desired application

region for one of thethree holes.

a

b

c

e

j



24/34

WS15-24



Step 12. Create Material Properties


25/34

WS15-25



Create the material properties

for the model.

a. Materials: Create /

Isotropic / Manual Inputb. EnterAluminum for

Material Name.

c. Click Input Properties

d. Enter10E6 forElastic

Modulus and 0.3 for the

Poisson Ratio.e. Click OK

f. Click Apply.

a

b

d

c

e

f


26/34

Step 14. Check the Load Case


27/34

WS15-27



Check the load case Default to

make sure that the load and

constraint are selected.

a. Load Cases: Modifyb. Click on the load case

name Default.

c. Check to see that both

the load and constraints

are assigned.

d. Click Cancel.

c

d

a

b

Step 15. Run the Analysis


28/34

WS15-28



Run the Analysis with

MSC.Nastran.

a. Analysis: Analyze / Entire

Model / Full Run.b. Click Translation

Parameters...

c. Make sure both XDB and

Print are selected for

Data Output.

d. Click OK.e. Click Solution Type

f. Make sure LINEAR

STATIC is selected.

g. Click OK.

h. Click Apply.

a

b

e

f

g

h

c

d

Step 16. Access the Results


29/34

WS15-29



Attach the XDB file to access the

results.

a. Analysis: Access Results/ Attach XDB / Result

Entities.

b. Click Select Results

File

c. Select

tension_fitting.xdb and

click OK.

d. Click Apply.

c

a

b

d

Step 17. Display Results


30/34

WS15-30



Create a deformation plot

a. Results: Create /Deformation.

b. SelectDisplacements,Transitional fromSelect DeformationResult.

c. Click Apply.

a

b

c

Step 17. Display Results (Cont.)


31/34

WS15-31



Erase the geometry and do not show

the undeformed model, so that only the

deformed model is shown.a. Display: Plot/Erase

b. Click Erase underGeometry.

c. Click OK.

d. Click Display Attributes.

e. Remove check from Show

Undeformed.f. For the Render Style, choose

Shaded.

g. Click Apply.

a

b

c

d

e

g

f

Step 17. Display Results (Cont.)


32/34

WS15-32



Step 17. Read Results (Cont.)


33/34

WS15-33



Plot the von Mises stress for the

model.

a. Results: Create / Fringe.

b. Select Stress Tensor

from Select Fringe Result.c. Select Display

Attributes, then set

Displayto Element

Edges

d. Click Apply.

e. Now turn off averagingand plot the stresses

again.

a

b

c

d

c

Step 17. Read Results (Cont.)


34/34

WS15-34



NAS120 WS14 Parasolid Modeling

Documents

Transcript of NAS120 WS14 Parasolid Modeling