WORKSHOP 5

COORDINATE SYSTEMS

WS5-2NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

WS5-3NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Workshop ObjectivesUnderstand the difference between Reference Coordinate System and Displacement Coordinate System

Problem DescriptionCreate two coordinate systems

Use one coordinate system to define the model

Use the second coordinate system to define the displacement coordinate system

WS5-4NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Suggested Exercise Steps1. Create a new database 2. Create a square surface3. Mesh the surface to create 2D elements. 4. Create material properties. 5. Create physical properties.6. Create a Nastran input file7. Review the Nastran input file8. Create two coordinate systems9. Modify the nodal coordinate systems10. Create a new Nastran input file11. Review the new Nastran input file

WS5-5NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

b c

d

f

g

Step 1. Create New Database

Create a new database called coord_system.db

a. File / New.b. Enter coord_system as

the 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

e

WS5-6NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Step 2. Create Geometry

Create a 1 x 1 surfacea. Geometry: Create /

Surface / XYZb. Click Apply.

a

b

WS5-7NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Step 3. Mesh the Surface

Mesh the surfacea. Elements: Create / Mesh

/ Surfaceb. Screen pick the surfacec. Enter 0.3 as the Global

Edge Lengthd. Click Apply.

a

b

c

d

WS5-8NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Step 4. Create Material Properties

Create an isotropic materiala. Materials: Create / Isotropic

/ Manual Input.b. Enter steel for the Material

Name.c. Click Input Properties.d. Enter 30e6 for the Elastic

Modulus.e. Enter 0.3 for the Poisson

Ratio.f. Click OK. g. Click Apply.

d

f

e

a

c

b

g

WS5-9NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Step 5. Create Physical Properties

Create physical propertiesa. Properties: Create / 2D /

Shellb. Enter plate as the Property

Set Name.c. Click Input Properties.d. Click on the Select

Material Icon.e. Click on steel to select itf. Enter 0.1 as the thicknessg. Click OK.

d

f

e

g

a

b

c

WS5-10NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Apply the physical propertiesa. Click in the Select

Members box.b. Screen pick the surfacec. Click Add.d. Click Apply.

Step 5. Create Physical Properties

b

ac

d

WS5-11NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Step 6. Create a Nastran Input File

Create a Nastran input filea. Analysis: Analyze / Entire

Model / Analysis Deckb. Click Apply.

a

b

WS5-12NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Step 7. Review the Nastran Input File

Examine the Nastran input filea. Open the directory in which your

database is saved.b. Find the file titled

coord_system.bdfc. Open this file with any text editor

and review it.d. Notice that field 3 and field 7 of the

GRID entries are blank which means the basic coordinate system (coordinate system 0) is used here.

Field 3 Field 7

WS5-13NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Step 8. Create a new coordinate system

Create a new coordinate systema. Geometry: Create / Coord

/ Eulerb. Enter 100 as the Coord IDc. Screen pick point 3 as the

origin

a

b

c

WS5-14NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Step 8. Create a second coordinate system

Create another coordinate systema. Geometry: Create / Coord /

Eulerb. Enter 200 as the Coord IDc. Click Rotation Parametersd. Enter 45 as the angle of

rotation about the z axise. Click OKf. Click in the Origin boxg. Screen pick point 4 as the

origin

a

b

c

d

ef

g

WS5-15NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Step 9. Modify the nodal coordinate frames

Modify the Reference Coordinate Frame

a. Elements: Modify / Node / Edit

b. Check the Refer. Coordinate Frame box

c. Rectangular select all nodes

d. Click in the Refer. Coordinate Frame box

e. Screen pick coord frame 100

f. Click Apply.

a

b

c

d

e

f

WS5-16NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Step 9. Modify the nodal coordinate frames

Modify the Analysis Coordinate Frame

a. Elements: Modify / Node / Edit

b. Uncheck the Refer. Coordinate Frame box and check the Analysis Coordinate Frame box

c. Rectangular select the lower row of nodes

d. Click in the Analysis Coordinate Frame box

e. Screen pick coord frame 200

f. Click Apply.

a

b

c

d

e f

WS5-17NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Step 10. Create a new Nastran Input File

Create a Nastran input filea. Analysis: Analyze / Entire

Model / Analysis Deckb. Enter coord_system_rev1

as the Job Namec. Click Apply.

a

b

c

WS5-18NAS120, Workshop 5, May 2006Copyright© 2005 MSC.Software Corporation

Step 11. Review the new Nastran Input File

Examine the Nastran input filea. Open the directory in which your

database is saved.b. Find the file titled

coord_system_rev1.bdfc. Open this file with any text editor

and review it.d. Notice that field 3 and field 7 of the

GRID entries have been changed.

Field 3 Field 7