COMPOSITE STRUCTURESEXAMPLE #4

THERMAL STRESS ANALYSIS OF COMPOSITE LAMINATE

Problem Description

Initial Temp = 130 C, Final Temp = 25 C

One-ply thickness = 1.0 mm

Stacking sequence = [0/90]T

E11 = 380 GPa, E22 = E33 = 8.2 GPa, 12 = 13 = 0.28, 23 = 0.47, G12 = G13 = 4.5 GPa, G23 = 4.5 GPa

11 = -0.5e-6, 22 = 25e-6

x

yz

500 mm

One point fixed

Step 1. Create Geometry & Mesh with CQUAD4 Elements

1010 mesh

Step 2. Create Constraints

a. Loads/BCs : Create / Displacement / Nodal

b. Select on New Set Name and enter displ_1

c. Select Input Data

d. Enter , for Translations and Rotations

e. OK

f. Click on Select Application Region

g. Select FEM for Geometry Filter

h. Select on the centre node

i. Add

j. OK

k. Apply

Step 3. Create Temperature Conditions

a. Loads/BCs : Create / Initial Temperature / Nodal

b. Select on New Set Name and enter ini_temp

c. Select Input Data

d. Enter 130 (C) for Initial Temperaturee. OK

f. Click on Select Application Region

g. Select Geometry for Geometry Filter

h. Pick the Surface or Face icon

i. Select on the surface

j. Add

k. OK

l. Apply

Step 3. Create Temperature Conditions (Contd)

a. Loads/BCs : Create / Temperature / Nodal

b. Select on New Set Name and enter temp

c. Select Input Data

d. Enter 25 (C) for Temperaturee. OK

f. Click on Select Application Region

g. Select Geometry for Geometry Filter

h. Pick the Surface or Face icon

i. Select on the surface

j. Add

k. OK

l. Apply

Step 3. Create Temperature Conditions (Cont.)

a. Select on Iso3 viewfrom the tool bar. Your model should look like the following.

Step 4. Define Material Properties MAT8

a. Materials : Create / 2d Orthotropic / manual Input

b. Select on Material Name and enter prepreg

c. Select Input Properties

d. Enter : Fill in properties

e. OK

f. Apply

Step 5. Define Failure Criteria

a. Click on prepreg in Existing Materials

b. Select Const. Model : Failure Failure Limits : Stress Comp Fail : Tsai-Wu

c. Enter : Fill in properties

d. OK

e. Apply

Step 6. Define Laminate PCOMP

a. Materials : Create / Composite / Laminate

b. Select prepreg in Existing Materials two times

c. Stacking Sequence Convention : Total

d. Fill in Stacking Sequence Definition Thickness : 1.0 mm Orientation : [0/90]

e. Select on New Material Nameand enter laminate

f. Apply

Step 7. Check [A], [B], and [D] Matrices

Step 8. Define Element Properties - PCOMP

a. Properties : Create / 2D / Shell

b. Select on Property Set Name and enter p_comp

c. Options : Laminate / Standard Formulation

d. Select Input Properties

e. Enter : Fill in properties

f. OK

g. Select on Application Region and pick to include all geometry as shown in the figure

h. Add

i. Apply

Step 9. Check Loads and Constraints

a. Load Cases : Modify

b. Select Default in Existing Load Cases

c. Make sure that all Loads and BCs are selected

d. Cancel

Step 10. Create NASTRAN Input File

a. Analysis : Analyze / Entire Model / Analysis Deck

b. Select Translation Parameters

c. Data Output : OP2

d. Bulk Data Format Sorted Bulk Data : No Card Format : small

e. OK

Step 10. Create NASTRAN Input File (Contd)

a. Select Solution Type

b. Choose LINEAR STATIC for Solution Type

c. OK

Step 10. Create NASTRAN Input File (Contd)

a. Select Output Requests in Subcases

b. Form Type : Advanced

c. Select STRESS(SORT1, ) in Output Requests

d. OptionsComposite Plate Opt : Ply & Elem. Stresses

e. OK

f. Apply Cancelg. Apply

Step 11. Read in OP2 File

a. Analysis : Access Results / Read Output2 / Result Entities

b. Click on Select Results File

c. Select thermal_analysis.op2

d. OK

e. Apply

Step 12. Results - Deformation

a. Results : Create / Deformation

b. Select Displacements, Translational under Select Deformation Result

c. Apply

Step 13. Results - Stress

a. Results : Create / Fringe

b. Select Stress Tensorunder Select Fringe Result

c. Position : Layer 1Quantity : X Component

d. Apply

.

Step 13. Results Stress (contd)

a. Results : Create / Fringe

b. Select Stress Tensorunder Select Fringe Result

c. Position : Layer 2Quantity : Y Component

d. Apply

Step 14. Results Failure Index

a. Results : Create / Fringe

b. Select Failure Indices, Ply Indices under Select Fringe Result

c. Position : Layer 1

d. Apply

Step 14. Results Failure Index (Contd)

a. Results : Create / Fringe

b. Select Failure Indices, Ply Indices under Select Fringe Result

c. Position : Layer 2

d. Apply

Exercise 1

Initial Temp = 130 C, Final Temp = 25 C One-ply Thickness = 1.0 mm Stacking Sequence = [02]T E11 = 380 GPa, E22 = E33 = 8.2 GPa, 12 = 13 = 0.28, 23 = 0.47,

G12 = G13 = 4.5 GPa, G23 = 4.5 GPa

11= -0.5e-6, 22= 25e-6

x

yz

500 mm

One point fixed

Exercise 2

x

yz

500 mm

clamped

clamped

Initial Temp = 130 C, Final Temp = 25 C One-ply Thickness = 1.0 mm Stacking Sequence = [02]T E11 = 380 GPa, E22 = E33 = 8.2 GPa, 12 = 13 = 0.28, 23 = 0.47,

G12 = G13 = 4.2 GPa, G23 = 4.2 GPa

11= -0.5e-6, 22= 25e-6