WORKSHOP 8A TENSION COUPON - unizg.hr

WORKSHOP 8A

TENSION COUPON

WS8A-2NAS120, Workshop 8A, May 2006Copyright© 2005 MSC.Software Corporation


Workshop ObjectivesBuild the tension coupon geometry

Control the mesh by using techniques discussed in class

Compare FEA stress results to theoretical results

From “Stress Concentration Factors” by R. E. Peterson, Figure 86:

σmax = 432 psi


Problem DescriptionA tension coupon is constructed from aluminum with E = 10 x 106

psi and n = 0.3

The coupon thickness is 0.125 in

An edge load of 50 lb is applied to the tension coupon


50 lb

10 in

4 in

2.0 DIA Hole


Suggested Exercise Steps1. Create a new database. 2. Create a geometry model of the tension coupon. 3. Use Mesh Seeds to define the mesh density.4. Create a finite element mesh.5. Verify the finite element mesh. 6. Define material properties. 7. Define element properties and apply them to the model. 8. Apply boundary conditions to the model.9. Apply loads to the model.10. Submit the model to MSC.Nastran for analysis.11. Post Process results using MSC.Patran.


b c

d

e

f

g

Step 1. Create New Database

Create a new database called tension_coupon_a.db.

a. File / New.b. Enter

tension_coupon_a 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


Step 2. Create Geometry

Create the first curve.a. Geometry: Create / Curve /

XYZ.b. Enter <0 4 0> for the Vector

Coordinate List.c. Enter [0 0 0] for the Origin

Coordinate List.d. Click Apply.

a

b

c

d



Create the second curve by translating the first curve.

a. Geometry: Transform / Curve / Translate.

b. Enter <10 0 0> for the Direction Vector.

c. Click in the Curve List box and screen pick the first curve.

a

b

c



Create two more curvesa. Geometry: Create / Curve /

Point.b. Screen pick the point at the

bottom of the left curve.c. Screen pick the point at the

bottom of the right curve. A curve is automatically created because Auto Execute is checked.

d. Screen pick the top of the left curve.

e. Finish creating the top curve by screen picking the point at the top of the right curve as shown.

a

b c

ed



Create a chain curvea. Geometry: Create / Curve /

Chain.b. Rectangular pick all four

curves.c. Click Apply.d. When the message box

appears, choose Yes to delete the original curves.

a

b

c

d



Create a circlea. Geometry: Create / Curve /

2D Circle.b. For the circle radius, enter

1.0.c. For the Center Point List,

enter [5 2 0].d. Click Apply.

a

c

b

d



Create a trimmed surfacea. Geometry: Create / Surface

/ Trimmed / Option: Planar.b. Click in the Outer Loop List

box.c. Screen pick the outer

curve.d. Click in the Inner Loop List

box.e. Screen pick the inner circle.f. Click Apply.g. When the message boxes

appear, choose Yes to delete the original curves.

h. Click the Refresh Graphics icon

a

b

d

c

e

f

g

h



Create two more circlesa. Geometry: Create / Curve /

2D Circle.b. For the circle radius, enter

1.1.c. For the Center Point List,

enter [5 2 0].d. Click Apply.e. Repeat this procedure for a

circle with a radius of 1.2.

a

b

d

c



Associate the two curves to the surface

a. Geometry: Associate / Curve / Surface.

b. Select the Curve filter.c. Rectangular pick both

circles.d. Screen pick the trimmed

surface.

ab

c

d


Step 3. Create Mesh Seeds

Create a uniform mesh seeda. Elements: Create / Mesh

Seed / Uniform.b. Enter 48 for the Number of

Elements.c. Click in the Curve List box.d. Select the Curve or Edge

element filter. e. Rectangular pick the two

circles and the edge of the hole.

a

b

c

d

e


Step 3. Create Mesh Seeds

Create a biased mesh seeda. Elements: Create / Mesh

Seed / Two Way Bias.b. Enter 20 for the Number of

Elements.c. Enter 0.25 for L2/L1.d. Click on the Curve List box. e. Screen pick the top edge of

the surface, as shown. f. Screen pick the bottom

edge of the surface to apply the mesh seed there as well.

a

bc

d

f

e


Step 4. Create Mesh

Create a finite element mesha. Elements: Create / Mesh /

Surface.b. Set the Element Shape to

Quad, Mesher to Paver, and Topology to Quad4.

c. Click in the Surface List box.

d. Screen pick the surface as shown.

e. Enter 1.0 as the value for Global Edge Length.

f. Click Apply.

a

b

cd

f

e


Step 5. Verify Mesh

Verify the quality of the finite elements

a. Elements: Verify / Quad / All.

b. Click Apply.c. When the message box

appears, click OK.d. Review the summary table.

a

b

c

d


Step 5. Verify Mesh

Perform specific quality tests on the elements.

a. Elements: Verify / Quad / Aspect.

b. Click Apply.c. When Message

appears, click OK.d. Review the fringe

plot.e. Repeat for Warp,

Skew, and Taper tests.

f. Reset Graphics.

d

a

b

d

ec

f


Step 6. Create Material Properties

Create an isotropic materiala. Materials: Create / Isotropic

/ Manual Input.b. Enter aluminum as the

Material Name.c. Click Input Properties.d. Enter 10e6 for the elastic

modulus and 0.3 for the Poisson Ratio.

e. Click OK. f. Click Apply.

d

e

a

b

c

f


Step 7. Create Element Properties

Create element 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 0.125 for the

thickness.g. Click OK.

d

f

g

e

a

b

c


Step 7. Create Element Properties

Select application regiona. Click in the Select

Members box.b. Screen pick the

surface as shown.c. Click Add.d. Click Apply.

b

a

c

d


Step 8. Apply Boundary Conditions

Create the 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 <0 0 0>for Rotations.

e. Click OK.

d

e

a

b

c



Apply the boundary conditiona. Click Select

Application Region.b. Select the Curve or

Edge filter.c. Select the left edge of

the surface as the application region.

d. Click Add.e. Click OK. f. Click Apply.

d

e

b

c

a

f



The boundary condition should agree with what’s shown on the right


Step 9. Apply Loads

Create the loada. Loads/BCs: Create / Total

Load / Element Uniform.b. Enter force as the New Set

Name.c. Set the Target Element

Type to 2D.d. Click Input Data.e. Enter <50 0 0> for the Edge

Load.f. Click OK.

e

f d

b

c

a


Apply the loada. Click Select Application

Region.b. For the application region

select the right edge of the surface as shown.

c. Click Add.d. Click OK.e. Click Apply.

Step 9. Apply Loads

b

c

da

e


Step 9. Apply Loads

The loads and boundary condition should agree with what’s shown on the right.


Step 10. Run Linear Static Analysis

Analyze the modela. Analysis: Analyze / Entire

Model / Full Run.b. Click Solution Type.c. Choose Linear Static.d. Click OK. e. Click Apply.

d

c

a

e

b


Step 11. Post Process with MSC.Patran

Attach the results filea. Analysis: Access Results /

Attach XDB / Result Entities.

b. Click Select Results File.c. Choose the results file

tension_coupon_a.xdb.d. Click OK. e. Click Apply.

c

d

a

b

e



Erase geometrya. Display: Plot/Erase.b. Under Geometry click

Erase.c. Click OK.

a

b

c



Create a Quick Plota. Results: Create / Quick

Plot.b. Select Stress Tensor

as the Fringe Result.c. Select Von Mises as

the Fringe Result Quantity.

d. Click Apply.

Max Von Mises Stress = ________

a

b

c

d



Create a Quick Plot of X Component Stress

a. Results: Create / Quick Plot.

b. Select Stress Tensor as the Fringe Result.

c. Select X Componentas the Fringe Result Quantity.

d. Click Apply.

Max X Stress = ________

b

c

d

a



Create a fringe plot of X Component Stress

a. Results: Create / Fringe.

b. Select Stress Tensor as the Fringe Result.

c. Select X Componentas the Fringe Result Quantity.

d. Click Apply.


d

a

b

c



By default, MSC.Nastran presents element stress results in the element coordinate system.

For the Fringe Plot option, MSC.Patran takes the MSC.Nastran results and plots them as is.

For the Quick Plot option, MSC.Patran automatically transforms the stress results into a projected Patranglobal coordinate system first before plotting them.



Show the element coordinate systems

a. Reset graphics.b. Elements: Show /

Element / Coord.Sysc. Rectangular pick all the

elements.d. Note the various

orientations of the X direction.

e. Click reset graphics.

b

c

e

a



Create another fringe Plota. Results: Create /

Fringe.b. Select Stress Tensor

as the Fringe Result.c. Select X Component

as the Fringe Result Quantity.

d. Click on the Plot Options Icon.

e. Set the coordinate transformation to CID.

f. Screen pick coordinate frame 0.

g. Click Apply.

a

b

c

de

f

g



View the revised resultsa. Note the change in

maximum stress.

Max X Stress = _________



Turn off averaginga. Set the Averaging

Definition Domain to None.

b. Click Apply.


a

b

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WORKSHOP 8A TENSION COUPON - unizg.hr