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A Preliminary Design Tool for <strong>Composites</strong><br />

Beam Structures : 3D-Beam II<br />

<strong>JEC</strong>, Paris<br />

March, 2011<br />

Sung K. Ha<br />

Hanyang University, Korea<br />

Stanford Composite Design Group<br />

1


Beam Type Structures of <strong>Composites</strong><br />

Wind Turbine Blades and Tower<br />

Wings<br />

Non Crimp Fabrics (NCF)<br />

HSCL Turbine<br />

Courtesy of Chomarat<br />

Sporting Goods<br />

Box beams<br />

2


3D Beam<br />

Analysis of Composite Strucutres Needs Ply-by-ply inputs such as<br />

thickness, ply orientation, and material properties.<br />

MS Excel based User-friendly FEA program for beam type structures.<br />

An accurate, yet easy-to-use tool , greatly simplifying data input<br />

procedures.<br />

<br />

<br />

<br />

<br />

<br />

<br />

Long Structures (compared to cross-section)<br />

Any cross-sections<br />

Tapered / Untapered beam structure<br />

Loads (3 forces / 3 moments) at any location<br />

Multiply connected frames<br />

Modal analysis<br />

3


FEM formulation for a composite beam: 3D-Beam<br />

At each node (6 dof)<br />

d , <br />

3 3<br />

1) Displacement<br />

u ( x, y, z)<br />

d x<br />

x<br />

1 1 3 2 2 3<br />

d<br />

,<br />

<br />

1 1<br />

d<br />

,<br />

<br />

2 2<br />

<br />

u ( x, y, z)<br />

d x<br />

2 2 3 1<br />

u ( x, y, z)<br />

d x<br />

3 3 2 1<br />

2) strain-displacement<br />

d1<br />

<br />

2<br />

<br />

3<br />

u<br />

,<br />

x3<br />

x2<br />

22<br />

u 2, 2<br />

0 33<br />

u 3,<br />

3<br />

0<br />

x x x<br />

11 1 1<br />

1<br />

1<br />

1<br />

n 3 '<br />

n 3<br />

<br />

n2 =n 2 '<br />

n<br />

n 1 '<br />

3 '<br />

n 3 ''<br />

<br />

n 1<br />

n 1 '=n 1 ''<br />

d1 C1 0 S1 D1<br />

<br />

d<br />

<br />

2<br />

S1S2 C2 CS<br />

<br />

<br />

<br />

1 2D2<br />

d SC S CC D<br />

<br />

3 1 2 2 1 2 3<br />

n 2 ''<br />

n 2 '<br />

<br />

<br />

1<br />

1 d2<br />

<br />

1<br />

( u<br />

,<br />

u<br />

,<br />

) <br />

x3<br />

<br />

2<br />

2 x1<br />

x1<br />

<br />

1<br />

1 d3<br />

<br />

1<br />

( u<br />

,<br />

u<br />

,<br />

) <br />

x2<br />

<br />

2<br />

2 x x <br />

12 12 21 3<br />

13 1 3 3 1 2<br />

1<br />

1<br />

<br />

23<br />

( u2, 3<br />

u3,<br />

2<br />

) 1<br />

<br />

1 0<br />

2<br />

2<br />

<br />

x<br />

x<br />

<br />

1 11 1 3 2 2 3<br />

<br />

2 x<br />

<br />

5 13 5 2 1<br />

<br />

2 x<br />

<br />

6 12 6 3 1<br />

1<br />

1<br />

4


FEM formulation for a composite beam<br />

3) Constitutive equation (stress-strain)<br />

<br />

1<br />

<br />

<br />

5<br />

<br />

<br />

<br />

6<br />

C C C<br />

<br />

<br />

<br />

C C C<br />

<br />

C C C<br />

11 15 16<br />

15 55 56<br />

<br />

<br />

<br />

<br />

<br />

1<br />

<br />

<br />

5<br />

<br />

<br />

<br />

6<br />

local 16 56 66 local local<br />

C<br />

Local<br />

<br />

1<br />

<br />

<br />

5<br />

<br />

<br />

<br />

6<br />

<br />

1 C C C x C x C x C x C<br />

<br />

<br />

5 <br />

<br />

<br />

C C C x C x C x C x C<br />

<br />

<br />

<br />

6 <br />

C C C x C x C x C x C<br />

local<br />

11 16 15 2 15 3 16 3 11 2 11<br />

15 56 55 2 55 3 56 3 15 2 15<br />

16 66 56 2 56 3 66 3 16 2 16<br />

Resultants Loads vs strains<br />

<br />

<br />

<br />

1<br />

<br />

<br />

6<br />

<br />

<br />

<br />

<br />

5 <br />

<br />

D'<br />

<br />

1<br />

<br />

<br />

<br />

<br />

2<br />

<br />

<br />

3 <br />

4) F.E. formulation<br />

<br />

T<br />

d <br />

<br />

<br />

<br />

1 <br />

<br />

<br />

1<br />

<br />

5<br />

<br />

6<br />

<br />

5<br />

d MD' d<br />

<br />

<br />

6 <br />

<br />

<br />

h<br />

h<br />

d N d , N ( i 1, 2,<br />

3)<br />

i<br />

2<br />

<br />

a1<br />

a ai i<br />

2<br />

<br />

a1<br />

a<br />

ai<br />

Laminates<br />

F<br />

A G G B B B <br />

<br />

<br />

1 11 16 15 11 12 13 1<br />

<br />

G<br />

2 66<br />

G56 B21 B22 B<br />

<br />

F<br />

<br />

23<br />

<br />

6 <br />

F<br />

G<br />

3 55<br />

B31 B32 B<br />

<br />

<br />

<br />

33 <br />

5 <br />

<br />

<br />

M<br />

D<br />

1 <br />

11<br />

D12 D13<br />

1<br />

<br />

M<br />

sym.<br />

D D <br />

<br />

2 22 23 2<br />

<br />

<br />

M<br />

D<br />

3 <br />

33 <br />

3<br />

M 3<br />

eg . ., A11 = C11dxdx<br />

2 3<br />

F 3<br />

M 1<br />

F 1<br />

F2<br />

M<br />

2<br />

e<br />

2<br />

T T<br />

k B DBdx<br />

B DB jd<br />

e ( ) ( )<br />

<br />

<br />

x<br />

x<br />

1<br />

e<br />

e<br />

2<br />

x<br />

e<br />

1<br />

1<br />

<br />

1<br />

f e<br />

N f dx<br />

N( ) f jd<br />

x<br />

<br />

e<br />

2<br />

x<br />

e<br />

1<br />

<br />

1<br />

1<br />

m e<br />

N m dx<br />

N( ) m jd<br />

x<br />

<br />

1<br />

1<br />

e e e e e<br />

m d<br />

+k d f MD+KD<br />

<br />

F<br />

5


FEM formulation for a composite beam<br />

Laminates<br />

x 1<br />

d<br />

,<br />

<br />

1 1<br />

d<br />

,<br />

<br />

3 3<br />

d<br />

,<br />

<br />

2 2<br />

M 3<br />

Q 3<br />

N 1<br />

M 1<br />

Q2<br />

M<br />

2<br />

5) strain-displacement<br />

6) Constitutive equation<br />

(macro strain macro stress)<br />

7) Failure criterion : Quadratic Tsai-Wu criterion<br />

SMM+<br />

MMF<br />

•Failure<br />

•Fatigue Life<br />

a F , b F<br />

( i 1, 2, 6)<br />

aR<br />

2<br />

ij i j i i<br />

bR 1 0 R <br />

<br />

<br />

<br />

0 :safe<br />

0 :fail<br />

Strength ratio<br />

1 0 :fail<br />

k <br />

R 0 :safe<br />

6


Coordinate systems and Layup direction<br />

Z<br />

Global<br />

Y<br />

Element<br />

X₃<br />

X₂<br />

Fiber direction<br />

Ply<br />

X 1<br />

X<br />

X₁ (S)<br />

, ply angle<br />

Cross Section<br />

<br />

Global coordinates (X-Y-Z)<br />

Element coordinates (X 1 -X 2 -X 3 )<br />

Local coordinates (x 1 -x 2 -x 3 )<br />

Layup Sequence<br />

Direction, t<br />

t<br />

n<br />

S<br />

n1<br />

n2<br />

L#<br />

n3<br />

Laminates<br />

Bricks<br />

x 3<br />

<br />

t sn<br />

X 3<br />

Plies<br />

x 2<br />

<br />

X 2<br />

7


Program Flow : 3D Beam<br />

Input<br />

• Cross Section<br />

• Material property<br />

• Nodes (Global coordinates)<br />

•Elements (node connectivity)<br />

• Boundary conditions<br />

• Global Forces<br />

Main Analysis Modules<br />

Step 1 : Section & Material<br />

Step 2 : Global Geometry<br />

Step 3 : Loads<br />

Step 4 : Solve<br />

Output<br />

• Displacement & Rotation<br />

• Global Strains & Curvatures<br />

• Global Loadings & Moments<br />

• In-Plane Strains<br />

• In-Plane Loads<br />

• Strength Ratios<br />

• Mode shape & Natural<br />

Frequency<br />

•Ply Stresses & Strains<br />

3D Graphical Post Processor:<br />

iPost.exe<br />

8


3D Beam– Main Sheet<br />

3D BEAM “Main” sheet<br />

2010-07-30<br />

9


Step 1 : Specification of Material Properties<br />

Material DB sheet<br />

10


Step 1 : Sections: Coordinates, Plies, and Laminates<br />

[A] n ,[B] n ,[D] n<br />

[A] k ,[B] k ,[D] k<br />

[A] 2 ,[B] 2 ,[D] 2<br />

L1<br />

L2<br />

(x2,x3)<br />

<br />

L3<br />

<br />

[A] 1 ,[B] 1 ,[D] 1<br />

Laminates bricks<br />

x 3<br />

<br />

X 3<br />

plies<br />

x 2<br />

<br />

X 2<br />

Laminate brick nodes<br />

nodes<br />

11


Step 1 : Sections: Coordinates, Plies, and Laminates<br />

3D BEAM “Section DB” sheet<br />

(4)<br />

[A] n ,[B] n ,[D] n<br />

[A] k ,[B] k ,[D] k<br />

[A] 2 ,[B] 2 ,[D] 2<br />

[A] 1 ,[B] 1 ,[D] 1<br />

L2<br />

<br />

L3<br />

(4)<br />

(3)<br />

(2)<br />

(3)<br />

L1<br />

(x2,x3)<br />

<br />

Material DB sheet<br />

• SI unit<br />

(1)<br />

Ply group number<br />

p8<br />

…<br />

p1<br />

(2)<br />

Laminates<br />

bricks<br />

x 3<br />

<br />

X 3<br />

plies<br />

x 2<br />

•English unit<br />

<br />

X 2<br />

brick nodes<br />

Laminate nodes<br />

12


e.g., A rectangular thin-wall cross section<br />

a2<br />

n<br />

a1<br />

t<br />

a2<br />

2<br />

Direction of ply sequence<br />

[0 3 /45/-45/90 2 ] s<br />

a1<br />

(-2 , 1)<br />

(2 , 1)<br />

a2<br />

x 3<br />

x 2<br />

a1<br />

x1<br />

x 3<br />

x 2<br />

t<br />

1<br />

2"<br />

3<br />

4<br />

(-2 , -1)<br />

(2 , -1)<br />

x1<br />

4"<br />

Laminate #1<br />

Laminate #2<br />

a1<br />

a2<br />

Laminate #3<br />

Laminate #4<br />

Base Line Option :0<br />

13


Step 2 : Global Geometry (nodes and elements)<br />

3D BEAM “Global geometry sheet”<br />

[A] n ,[B] n ,[D] n<br />

[A] k ,[B] k ,[D] k<br />

[A] 2 ,[B] 2 ,[D] 2<br />

[A] 1 ,[B] 1 ,[D] 1<br />

14


3D BEAM “Loads sheet”<br />

Step 3 : Loads: forces and moments<br />

[A] n<br />

,[B] n<br />

,[D] n<br />

[A] k<br />

,[B] k<br />

,[D] k<br />

[A] 2<br />

,[B] 2<br />

,[D] 2<br />

Displacements & Rotations<br />

<br />

U 3<br />

[A] 1<br />

,[B] 1<br />

,[D] 1<br />

Z<br />

Y<br />

U 2<br />

<br />

X U 1 <br />

Forces & Moments<br />

M 3<br />

F 3<br />

M 2<br />

Z<br />

Y<br />

F 2<br />

X F 1 M 1<br />

<br />

Global coordinates (X-Y-Z)<br />

15


Step 4 : Results: Deflections, in-plane loads, etc.<br />

Y<br />

X<br />

0.5m<br />

1kN<br />

0.03m<br />

•Displacements &<br />

•Forces<br />

•Moments<br />

<br />

M<br />

• Rotations<br />

3<br />

U 3<br />

F 3<br />

Z<br />

<br />

Z<br />

M 2<br />

U 2<br />

F<br />

Y<br />

2<br />

Y<br />

X U 1 <br />

X F 1 M 1<br />

Cross-section:<br />

20 segments (laminates)<br />

‣ resultant forces<br />

0.005<br />

0<br />

‐0.005<br />

‐0.01<br />

‐0.015<br />

‐0.02<br />

‐0.025<br />

‐0.03<br />

Deflection along the X‐axis<br />

0 0.1 0.2 0.3 0.4 0.5 0.6<br />

U₁<br />

U₂<br />

U₃


Step 4 : Results: failure index, in-plane loads, etc.<br />

3D BEAM “Results sheet”<br />

at each section<br />

Cross‐section<br />

0.02<br />

[A] n ,[B] n ,[D] n<br />

[A] k ,[B] k ,[D] k<br />

[A] 2 ,[B] 2 ,[D] 2<br />

N 1<br />

N 2<br />

N 6<br />

0.015<br />

0.01<br />

[A] 1 ,[B] 1 ,[D] 1<br />

0.005<br />

0<br />

‐0.02 ‐0.015 ‐0.01 ‐0.005 0 0.005 0.01 0.015 0.02<br />

‐0.005<br />

z_b<br />

zT<br />

zB<br />

‐0.01<br />

‐0.015<br />

‐0.02<br />

At each section, in-plan loads, strains and strength ratios<br />

0.8<br />

0.6<br />

0.4<br />

0.2<br />

0<br />

‐0.2<br />

‐0.4<br />

‐0.6<br />

‐0.8<br />

In Plane stress at Element # 1<br />

N1<br />

N2<br />

N6<br />

0 5 10 15 20 25<br />

Laminate #<br />

0.006<br />

0.004<br />

0.002<br />

0<br />

‐0.002<br />

‐0.004<br />

‐0.006<br />

In Plane strain at Element # 1<br />

e1<br />

e2<br />

e6<br />

0 5 10 15 20 25<br />

Laminate #<br />

17<br />

16<br />

15<br />

Laminat #<br />

18<br />

14<br />

19<br />

13<br />

201.2<br />

1<br />

0.8<br />

0.6<br />

0.4<br />

0.2<br />

0<br />

‣Strength 12 ratio<br />

1<br />

11<br />

2<br />

10<br />

3<br />

9<br />

Failure Index (1/R)<br />

4<br />

5<br />

6<br />

7<br />

8<br />

17


Installation : 3D-beam and iPost (Graphic Post Processor)<br />

1 – Copy and Paste the 3D-beam and iPost into your folder.<br />

2. If needed, Install JRE (Java Runtime Environment) on your system to run JAVA Post<br />

Processor. You can download JRE from http://java.sun.com/javase/downloads/index.jsp<br />

This application is available for all operating systems.<br />

3 – Be sure to place “iPost.exe” file at same location as the 3D Beam II.xlsm software.<br />

Figure : 3D-beam & iPost<br />

18


iPost – Overview<br />

Post Process File Selection<br />

Parameter Setting<br />

Display Setting<br />

Graphics Area<br />

Field Output:<br />

Contour Values<br />

Note!!<br />

Current generated Post Process file will be automatically called.<br />

19


iPost– Parameter Setting<br />

Parameter Setting<br />

Scale Factor: 0.1 Scale Factor: 1<br />

Field Outputs:<br />

Nstress: stress from node<br />

Disp: displacement distribution<br />

Mode: mode shape<br />

Mat Number:<br />

All: elements with all mat<br />

1: elements with mat 1<br />

2: elements with mat 2<br />

& so on…<br />

Scale Factor:<br />

Any value<br />

20


iPost– Display Setting<br />

Display Setting<br />

On<br />

Off<br />

Window:<br />

1, 2, 4<br />

Wire Fram:<br />

On/Off<br />

Deformed<br />

Deformed & Undeformed<br />

Background:<br />

White/Black<br />

Deformed/Undeformed<br />

21


Comparison between 3D Beam and<br />

commecial FEA tools<br />

22


Case : Hollow Composite Beam with Circular Cross-section<br />

Deformation under simple loading<br />

Vertical<br />

100 N<br />

Torsion<br />

100 N · m<br />

D = 0.1 m<br />

L = 1 m<br />

[0/±45/90] S<br />

1.2<br />

Deflection<br />

Deformation normalized by Abaqus result<br />

1<br />

0.8<br />

0.6<br />

0.4<br />

0.2<br />

3D Beam II<br />

Abaqus<br />

0<br />

Deflection<br />

Rotational Angle<br />

Rotational Angle<br />

23


Case : Hollow Composite Beam with Circular Cross-section<br />

Natural frequencies & mode shapes<br />

D = 0.1 m<br />

L = 1 m<br />

[0/±45/90] S<br />

Mode 1<br />

Mode 2<br />

Natural Frequency (Hz)<br />

1800<br />

1600<br />

1400<br />

1200<br />

1000<br />

800<br />

600<br />

400<br />

3D Beam II<br />

Abaqus<br />

Mode 3<br />

200<br />

0<br />

Mode 1 Mode 2 Mode 3 Mode 4<br />

Mode 4<br />

24


Case : Hollow Composite Beam with Square Cross-section<br />

Results<br />

L = 1 m<br />

Load Case 1 Load Case 2<br />

100 N 100 N · m<br />

Load Case 1 : Max. Displacement<br />

Dispalcement (m)<br />

1.60E‐04<br />

1.40E‐04<br />

1.20E‐04<br />

1.00E‐04<br />

8.00E‐05<br />

6.00E‐05<br />

4.00E‐05<br />

2.00E‐05<br />

0.00E+00<br />

Abaqus (Shell Element)<br />

A<br />

3D Beam II5.50<br />

Load Case 2 : Max. Rotation<br />

Rotation (radians)<br />

8.00E‐04<br />

7.00E‐04<br />

6.00E‐04<br />

5.00E‐04<br />

4.00E‐04<br />

3.00E‐04<br />

2.00E‐04<br />

1.00E‐04<br />

0.00E+00<br />

Abaqus (Shell Element)<br />

3D Beam II5.50<br />

H = 0.1m<br />

H = 0.1m<br />

W = 0.1m<br />

W = 0.1m<br />

Laminate Layup : [0 8 /±45 8 /90 8 ] S<br />

Material : AS/H3501<br />

Abaqus<br />

(Shell Element)<br />

3D Beam II5.50<br />

Load Case 1<br />

Load Case 2


Case : Hollow Composite Beam with Square Cross-section<br />

Results : Natural Frequencies & Mode shapes<br />

Abaqus<br />

(Shell Element)<br />

Abaqus<br />

(Beam Element)<br />

3D Beam II5.50<br />

L = 1 m<br />

Laminate Layup : [0 8 /±45 8 /90 8 ] S<br />

Material : AS/H3501<br />

Mode 1<br />

130.45 120.32 132.64<br />

Frequency (Hz)<br />

1800<br />

1600<br />

1400<br />

1200<br />

1000<br />

800<br />

600<br />

Abaqus (Shell Element)<br />

Abaqus (Beam Element)<br />

3D Beam II5.50<br />

Mode 2<br />

705.49 972.93 743<br />

400<br />

200<br />

0<br />

1st Mode 2nd Mode 3rd Mode 4th Mode<br />

Mode 3<br />

792.25 791.77 923.59<br />

Mode 4<br />

1539.5 1648.8 1481.6


Case :Ellipse Composite Beam<br />

Results<br />

D = 0.1 m<br />

L = 1 m<br />

Load Case 1 Load Case 2<br />

100 N<br />

100 N · m<br />

Load Case 1 : Max. Displacement<br />

Dispalcement (m)<br />

8.00E‐03<br />

7.00E‐03<br />

6.00E‐03<br />

5.00E‐03<br />

4.00E‐03<br />

3.00E‐03<br />

2.00E‐03<br />

1.00E‐03<br />

0.00E+00<br />

Abaqus (Shell Element) Abaqus (Beam Element) 3D Beam II5.50<br />

Load Case 2 : Max. Rotation<br />

Rotation (radians)<br />

2.50E‐02<br />

2.00E‐02<br />

1.50E‐02<br />

1.00E‐02<br />

5.00E‐03<br />

0.00E+00<br />

Abaqus (Shell Element)<br />

Abaqus (Beam<br />

Element)<br />

3D Beam II5.50<br />

5 cm<br />

5 cm<br />

10 cm<br />

Laminate Layup : [0/±45/90] S<br />

Material : AS/H3501<br />

10 cm<br />

Abaqus<br />

(Shell Element)<br />

Abaqus<br />

(Beam Element)<br />

3D Beam II5.50<br />

Load Case 1<br />

Load Case 2


Case :Ellipse Composite Beam<br />

Results : Natural Frequencies & Mode shapes<br />

D = 0.1 m<br />

Abaqus<br />

(Shell Element)<br />

Abaqus<br />

(Beam Element)<br />

3D Beam II5.50<br />

L = 1 m<br />

61.46 61.61 61.93<br />

Laminate Layup : [0/±45/90] S<br />

Material : AS/H3501<br />

Mode 1<br />

Frequency (Hz)<br />

700<br />

600<br />

500<br />

400<br />

300<br />

200<br />

100<br />

Abaqus (Shell Element)<br />

Abaqus (Beam Element)<br />

3D Beam II5.50<br />

Mode 2<br />

Mode 3<br />

103.88 101.95 104.93<br />

366.15 379.43 371.56<br />

0<br />

1st Mode 2nd Mode 3rd Mode 4th Mode<br />

Mode 4<br />

613.01 610.32 620.27


Parametric study using 3D Beam<br />

29


.<br />

Parametric Study-Easy to change the layup angles<br />

3D BEAM “Section DB” sheet<br />

Plies<br />

Laminates<br />

Change ply angle for 3 cases<br />

θ<br />

Case (1) 30°<br />

Case (2) 45°<br />

Case (3) 60°<br />

•[0/±θ/90]s<br />

30


Results: a clamped beam with circular cross-section<br />

Y<br />

Z<br />

Displacement U3<br />

Z<br />

X<br />

X<br />

Case (1) : θ = 30° ; Deflection= -0.014 m<br />

Case (2) : θ = 45° ; Deflection= -0.018 m<br />

Case (3) : θ = 60° ; Deflection= -0.020 m<br />

31


Results: a clamped beam with circular cross-section<br />

A cantilever beam<br />

under concentrated<br />

tip load<br />

Results at the root<br />

In plane load<br />

BOTTOM<br />

Fixed<br />

TOP<br />

L9<br />

L10<br />

L11<br />

L8<br />

Y<br />

L7<br />

L6 L5<br />

L4<br />

L3<br />

TOP<br />

Z<br />

L2<br />

(Global Z coordinate)<br />

L1<br />

Y<br />

L20<br />

In plane strain<br />

BOTTOM<br />

L12<br />

L13<br />

L14<br />

BOTTOM<br />

L15 L16<br />

L17<br />

X<br />

L18<br />

L19<br />

TOP<br />

- In plane load & strain are same for<br />

case(1),(2) and (3).<br />

32


Effect of fiber angles on stress distribution: Circular Beam<br />

At root<br />

Fixed<br />

L8<br />

L7<br />

L6<br />

TOP<br />

L5<br />

L4<br />

L3<br />

L9<br />

L10<br />

Z<br />

(Global Z coordinate)<br />

L2<br />

L1<br />

L11<br />

Y<br />

Y<br />

L20<br />

L12<br />

L13<br />

L14<br />

BOTTOM<br />

L15<br />

L16<br />

L17<br />

X<br />

L18<br />

L19<br />

Laminate #<br />

Tension<br />

Compression<br />

Small fiber angle reduces strength ratios<br />

θ<br />

Fiber<br />

33


Effect of ply angles on natural frequencies : Circular Beam<br />

Natural frequencies & modal shapes<br />

1 st Mode shape<br />

2 nd Mode shape<br />

3 rd Mode shape<br />

Case(1)<br />

: 30°<br />

Case(2)<br />

: 45°<br />

Case(3)<br />

: 60°<br />

34


Analysis of a Bend-Twisting Coupled<br />

Box Beam<br />

35


Tension-Shear Coupling in a laminate<br />

A tension-shear coupling term,<br />

A 16<br />

Balanced<br />

x 2<br />

x 1<br />

A16 0<br />

6 0<br />

N 1<br />

1<br />

1 A11 A12 0 N1<br />

<br />

<br />

A A 0 N<br />

2 21 22 2<br />

<br />

<br />

6<br />

0 0 A <br />

66<br />

N <br />

<br />

<br />

<br />

6<br />

<br />

<br />

Unbalanced<br />

x 2<br />

x 1<br />

A16 0<br />

<br />

6<br />

0<br />

N 1<br />

1<br />

1 A11 A12 A <br />

16 N1<br />

<br />

<br />

A A A N<br />

2 21 22 26<br />

2<br />

<br />

<br />

6<br />

A61 A62<br />

A <br />

66<br />

N <br />

<br />

<br />

<br />

6


Bend-Twist Coupling<br />

M<br />

EI<br />

C 2<br />

<br />

T<br />

<br />

C GJ<br />

<br />

1<br />

<br />

[0 / ] 100<br />

A<br />

16<br />

0<br />

If isotropic or balanced,<br />

For unbalanced, C 0<br />

C 0<br />

Twist<br />

Bend<br />

[0 / ] 100<br />

A<br />

16<br />

0<br />

37


A composite bend/twist coupled box beam.<br />

A bend/twist coulpled box-beam.<br />

Tip<br />

y<br />

x<br />

z<br />

<br />

Z<br />

ply thickness: 0.1 mm<br />

composite material : IM6/ep<br />

[ 45 80]<br />

[0 / ] 100<br />

[0 / ] 100<br />

bidirectional upper NCF:<br />

bidirectional lower NCF:<br />

length:10 m<br />

height:0.5 m<br />

width:0.5 m<br />

[0 / ] m<br />

[0 / ] m


Bend/twist coupling using birectional NCF<br />

Analysis tool : 3D-beam<br />

4<br />

L#3<br />

3<br />

0.24<br />

0.14<br />

0.04<br />

L#4<br />

‐0.252 ‐0.152 ‐0.052 0.048 0.148 0.248<br />

Base line<br />

Top line<br />

Bottom line<br />

[0 / ] m<br />

‐0.06<br />

L#2<br />

‐0.16<br />

[ 45] n<br />

[0 / ] m<br />

[ 45] n<br />

L#1<br />

‐0.26<br />

1 2


Bend/twist coupling using birectional NCF<br />

Analysis tool : 3D-beam<br />

twist/bend coupling,<br />

Z<br />

<br />

d<br />

d <br />

twisting angle, deg<br />

bending angle, deg<br />

Bidirectional NCF can be used to cause an intrinsically bend/twist coupling.<br />

0.25<br />

0.2<br />

bending angle, deg<br />

0.5<br />

0<br />

Z<br />

<br />

d<br />

d <br />

[ 45] n<br />

[0 / ] m<br />

[0 / ] m<br />

[ 45] n<br />

0.15<br />

0.1<br />

0.05<br />

0<br />

twisting angle, deg<br />

0 15 30 45 60 75 90<br />

-0.5<br />

-1<br />

-1.5<br />

-2<br />

twist/bend coupling<br />

outer ply angle, , deg


Zero displacement using Bend-Twist coupling<br />

Deflection, m<br />

Rotation, deg<br />

[ 4580]<br />

[0100 / 100]<br />

[ 45 ]<br />

80<br />

[0100 / 100]<br />

Top : [0 / 45 ]<br />

100 100<br />

Bottom : [0 / 45 ]<br />

100 100<br />

, deg<br />

Bending + Torsion<br />

No deflection<br />

Bending force only<br />

P<br />

+ <br />

P 0.78N<br />

0.78N<br />

Torsion only T 1 Nm T 1 Nm


Application to Braided Composite Beams<br />

42


Beam Type Composite Applications: Braided composites<br />

<br />

Braided <strong>Composites</strong><br />

Airbeams, framing<br />

aircraft maintenance hangars <br />

Composite Bridge Arches<br />

<br />

High Tech Hockey Stick<br />

<br />

Baseball composites bats<br />

by courtesy of A&P Technology<br />

43


Braided structure with varying cross-sections<br />

30°<br />

2θ<br />

<br />

45°<br />

60°<br />

length<br />

width<br />

44<br />

2011,03,021


Variation of Material Properties with Braid angle<br />

45


Baided Beam with Varying Cross-sections<br />

[ / <br />

] m<br />

46


Application to Design of Wind Turbine<br />

Blades<br />

HSCL Turbine<br />

47


Application: 5 kW Wind turbine blades<br />

• Rated Power: 5 kW<br />

• Rated wind speed: 10 m/s<br />

• Hub height: 10 m<br />

• Rotor diameters: 2.5 m<br />

• Cut in wind speed: 4 m/s<br />

• Cut out wind speed: 25 m/s<br />

• Annual mean wind speed: 5 m/s<br />

• Average Reynolds # : 1.5 x 10 6<br />

• Vertical Wind Shear: α = 0.2<br />

• Weibull Distribution: k = 2<br />

• Blades = 3<br />

• Orientation = Upwind<br />

• Rotation = Clockwise<br />

• Speed = Variable<br />

• Control = Pitch regulated<br />

*Reference: Finite element analysis with an improved failure criterion<br />

for composite wind turbine blades, Forsch Ingenieurwes (2008) 72: 193–207<br />

Hub<br />

D<br />

Hub height<br />

Airfoil NACA 4412<br />

Rotor Radius = 2.5 m<br />

Sections = 12<br />

Twist = 18 o<br />

Neck<br />

0º<br />

Material:<br />

Hub Metal and Composite*<br />

Neck Composite*<br />

Shell Composite*<br />

Fig: Model of a wind turbine blade<br />

* E-glass LY556 epoxy resin lamina Twist<br />

angle<br />

Shell<br />

18º<br />


Application: Wind turbine blades<br />

Distributed loads : Fz/length= 350N/ (2.5 m)<br />

[ Al(4mm)/0 8 / (±45) 4 ]<br />

[ 0 8 / (±45) 4 ]<br />

2.5m<br />

[ 0 6 / (±45) 2 ]<br />

Layup sequence<br />

Material : E-glass LY556<br />

Wing sections<br />

Airfoil NACA 4412<br />

Twist = 18 o<br />

0.08<br />

0.06<br />

0.04<br />

0.02<br />

0<br />

‐0.02 0 0.02 0.04 0.06 0.08 0.1 0.12 0.14 0.16<br />

‐0.02<br />

‐0.04<br />

‐0.06<br />

‐0.08


Application : Wind turbine blade<br />

50


Application : Wind turbine blade<br />

Element #1<br />

In Plane stress at Element # 1<br />

0.03<br />

N1<br />

0.02<br />

N2<br />

0.01<br />

N6<br />

0<br />

‐0.01<br />

0 5 10 15 20 25<br />

‐0.02<br />

‐0.03<br />

Laminate #<br />

Element #4<br />

In Plane stress at Element # 4<br />

0.04<br />

N1<br />

0.03<br />

N2<br />

0.02<br />

N6<br />

0.01<br />

0<br />

‐0.01 0 5 10 15 20 25<br />

(1)<br />

‐0.02<br />

‐0.03<br />

‐0.04<br />

Laminate #<br />

Element #8<br />

In Plane stress at Element # 8<br />

0.06<br />

N1<br />

0.04<br />

N2<br />

0.02<br />

N6<br />

0<br />

‐0.02<br />

0 5 10 15 20 25<br />

‐0.04<br />

‐0.06<br />

Laminate #<br />

In Plane strain at Element # 1<br />

0.00008<br />

0.00006<br />

0.00004<br />

0.00002<br />

e1<br />

e2<br />

e6<br />

0<br />

‐0.00002 0 5 10 15 20 25<br />

‐0.00004<br />

‐0.00006<br />

‐0.00008<br />

Laminate #<br />

(8)<br />

In Plane strain at Element # 4<br />

0.0006<br />

(4)<br />

0.0004<br />

0.0002<br />

e2<br />

e6<br />

0<br />

‐0.0002<br />

0 5 10 15 20 25<br />

‐0.0004<br />

‐0.0006<br />

Laminate #<br />

In Plane strain at Element # 8<br />

0.0015<br />

0.001<br />

e1<br />

e2<br />

0.0005<br />

e6<br />

0<br />

0 5 10 15 20 25<br />

‐0.0005<br />

‐0.001<br />

Laminate #<br />

e1<br />

19<br />

18<br />

17<br />

16<br />

15<br />

14<br />

13<br />

Laminat #<br />

19<br />

18<br />

17<br />

16<br />

15<br />

14<br />

13<br />

Laminat #<br />

19<br />

18<br />

17<br />

16<br />

15<br />

14<br />

13<br />

Laminat #<br />

1<br />

20 0.015<br />

0.01<br />

0.005<br />

0<br />

12<br />

11<br />

1<br />

200.1<br />

0.08<br />

0.06<br />

0.04<br />

0.02<br />

0<br />

12<br />

11<br />

1<br />

200.2<br />

0.15<br />

0.1<br />

0.05<br />

0<br />

12<br />

11<br />

2<br />

10<br />

2<br />

10<br />

2<br />

10<br />

Failure Index (1/R)<br />

3<br />

4<br />

5<br />

6<br />

7<br />

8<br />

9<br />

Failure Index (1/R)<br />

3<br />

4<br />

5<br />

6<br />

7<br />

8<br />

9<br />

Failure Index (1/R)<br />

3<br />

4<br />

5<br />

6<br />

7<br />

8<br />

9<br />

51


Effects of stiffeners thickness on wind turbine blades<br />

Stiffener T300/N5208 [0 n ]<br />

E-glass/LY556 Epoxy<br />

Leading edge<br />

Trailing edge<br />

Upper Spar Cap<br />

Lower Spar Cap<br />

[0/+45/0] 60 [0/+45/0] 40 [0/+45/0] 40 [0/+45/0] 10<br />

Shear web [0/+45/0] 8 [0/+45/0] 8 [0/+45/0] 8 [0/+45/0] 8<br />

Stiffener T300/N5208<br />

Case (1) : n = 0;<br />

Case(2) : n = 10;<br />

Case(3) : n = 20.<br />

52


Blade deflection : Ultimate load<br />

Ultimate load at the tip<br />

4,000 N/m<br />

Deflection<br />

: No Stiffener<br />

: Stiffener =[0 10 ]<br />

T300/N5208<br />

: Stiffener =[0 20 ]<br />

T300/N5208<br />

53


Strength ratio : Ultimate load<br />

(1) (2) (3)<br />

Strength ratio (Tsai-Wu)<br />

(1) (2) (3)<br />

Laminate #<br />

L8 L7 L6 L5<br />

L10 L9<br />

L4<br />

L3<br />

L11<br />

L25<br />

L2<br />

L1<br />

L12 L26<br />

L28<br />

L29<br />

L27<br />

L30<br />

L13<br />

L14 L15 L16 L17 L18 L19 L20 L21 L22 L23 L24<br />

54


Vibration mode<br />

: No Stiffener<br />

: Stiffener =[0 10 ] Graphite<br />

: Stiffener =[0 20 ] Graphite<br />

1 st mode shape<br />

1 st 2 nd 3 rd 4 th<br />

Vibration modes<br />

2 nd mode shape 3 rd mode shape 4 th mode shape<br />

55


Summary and Conclusion<br />

• The 3D-beam can be used as a preliminary design tool for compoiste structures.<br />

• It is based on a composite beam theory, yielding as accurate results as 3D modeling.<br />

• Yet easy-to-use tool.<br />

• Calculate displacements, strains, stresses, failure index and natural vibration modes.<br />

• Biaxial unbalanced laminates and beams,<br />

• Braided Composite Beams<br />

• A “3D Beam II5.55p” (public version) is available to the audience.<br />

Thank you for your attention !!!<br />

sungha@hanyang.ac.kr<br />

title: 3DBEAM<br />

56

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