Analysis of 2D Triaxial Braided Textile Composites & FEXL · 2012-03-08 · Slide 3 Introduction to...

Analysis of 2D Triaxial Braided

Textile Composites & FEXL

Sung Kyu Ha, Kyu Kook Jin, Xu Lei

Structures and Composites Laboratory

Hanyang University

Slide 2

Macro, Meso and Micro Mechanics

UNIT CELL

OF UNIDIRECTIONALTAPECOMPOSITE STRUCTURE

Thermal

Mechanical

Loads

(k) (k)M and ASTRESS AMPLIFICATION FACTORS

OF UNIDIRECTIONAL COMPOSITE

(i) (i)M and ASTRESS AMPLIFICATION FACTORS

OF MESO MODELS

(i,k) (k) (ki )( )σ σ=M + A ΔT

Cand EFFECTIVE MATERIAL PROPERTIES


Cand αEFFECTIVE MATERIAL PROPERTIES

OF MESO MODELS

MICRO-STRESSES


(i)i) (i)( σ=M +σ A ΔT

MESO-STRESSES

OF MESO MODELS

MACRO-STRESSES

σ

Micro-Mechanics Meso-Mechanics (fiber architecture) Macro-Mechanics

(k)(i)

FEM

Braided Composite

MESO MODELS MICRO MODELS

Unit Cell

Slide 3

Introduction to Braided Textile Composites

Fig1. 2D Braided composite

Fig2. GEnx jet engine with

a braided composite fan

Advantages

1. Better out-of-plane stiffness, strength, and toughness

2. Lower fabrication costs, and easier handling in production

quality than tape laminates

Braid Patterns

Diamond Braid (1/1) Regular Braid (2/2) Hercules Braid (3/3)

Diamond Braid — 1 up, 1 down (1/1)

Regular Braid — 2 up, 2 down (2/2)

Hercules Braid —3 up, 3 down (3/3)

Slide 4

Key parameters of (2/2) Triaxial Braided

Composite

θ — braiding angle

Wa — width of axial yarn

Wb — width of bias yarn

ta — thickness of axial yarn

tb — thickness of bias yarn

Introduction to Braided Textile Composites

Components of (2/2) Triaxial Braided Composite

1. Axial yarn

2. -θ Bias yarn

3. +θ Bias yarn

Green — -θ bias yarns Blue — axial yarns Red — θ bias yarns

θ

Wb

Wa θ

tb

ta

tb

Slide 5

CAD Model

Unit Cell for Braided Composite

CAD Model for 2/2 Triaxial Braided Composite

Bias yarns

Axial yarns

Bias yarn cross section Axial yarn cross section

ab — width of bias yarn

bb — thickness of bias yarn

a — width of axial yarn

b— thickness of axial yarn

Undulation of bias yarn

z’= Asin(πx’/L)

Governing equation

Slide 6

CAD Model of Repeating Unit Cell (RUC)

Unit Cell

Resin

Yarn

Red: +θ Bias Yarn

White: -θ Bias Yarn

Green: Axial Yarn

Unit Cell of Braided Composite

FEM Model of RUC

Mesh of Unit Cell Mesh of Fiber Mesh of Resin

Slide 7

Analysis of Multi-Cell Model of Braided Composite

Unit Cell

Resin

Fiber

Geometry Information

Braiding angle: θ = 30°;

Width of axial yarn: Wa = 3.012mm

Width of bias yarn: Wb = 3.01mm

Thickness of axial yarn: ta = 0.503mm

Thickness of bias yarn: tb = 0.498mm

Multi Cell Model

Slide 8

Assign material properties

Material Properties

E1(GPa) E2(GPa) E3(GPa) ν12 ν13 ν23 G12(GPa) G13(GPa) G23(GPa)

231 18 18 0.2 0.2 0.35 85 85 7Fiber

MatrixE(GPa) ν

4 0.38

Local Coordinate System (CSYS)

Cell_1 – Local CSYS_1

Cell_2 – Local CSYS_2

Cell_n – Local CSYS_n

CSYS_n

CSYS_1

CSYS_2

All Repeating Local CSYSs

Slide 9

Load & Boundary Conditions

X: U(x) = 0

Y: U(y) = 0z

xy

x

x’

y

y’

P

X’: DOF_1(x’) = DOF_1(P)

Y’: DOF_2(y’) = DOF_2(P)

Boundary conditions

Loads

z

xy

Analysis 1

σ = 1

z

xy

Analysis 2

ε = 1

Slide 10

Layers align configuration for NCF

Analysis results

Analysis 1 Analysis 2

Field Output: Stress, Mises

The two analysis under two different loads have the same stress distribution

ε = 1σ = 1

Slide 11

Layers align configuration for NCF

Analysis results

Analysis 1 Analysis 2

Field Output: Strain, Max, Principal

The two analysis under two different loads have the same strain distribution

ε = 1σ = 1

Slide 12

Summary of Braided Textile Composite

The unit cell of 2/2 braided composite has been defined;

The cad model and FEM model of 2/2 braided textile composite have

been developed;

The analysis of multi cell model has been finished.

A finite element program for Axisymmetric

Composite Structures : FEXL-AxiCom

13

Slide 14 14

What are Axisymmetric Structures?

Water tanks Pipes

Pressure vess

els

……

Cap

Rotors

Slide 15 15

FEXL-AxiCom

MS Excel based User-friendly finite element analysis program

for Axisymmetric Composite Structures

Axisymmetric Structure with

any cross section

Two loads (Internal pressure and

angular velocity) at any location

The FEXL-AxiCom is an accurate, yet easy-to-

use tool , greatly simplifying data input procedures

for cross-sections and layup sequences.

Slide 16

Main Analysis

Modules

Step 1 : Geometry

Selection

Step 2 Material

Properties

Step 3 : Loads

Step 4 : Solve

•Decide the dimensions

for the selected model

• Number of nodes

• Internal Pressure

• Angular velocity

Input Output

• Displacement

• Global Strains

• Global Stresses

Program Flow : FEXL-AxiCom

3D Graphical Post Processor:

JAVA PostProcessor

Step 4 : Mesh Generation

Slide 17

Introduction of FEXL-AxiCom

FEXL-AxiCom “Main” sheet

Pressure

Vessel

Cylinder Sphere

Material DB

Application of FEXL-AxiCom

18

Slide 1919

Composite

Cylinders

Composite

Pressure Vessels

Samples

Composite

Spherical Cap

Slide 20

Analysis of Composite Cylinder under Internal Pressure

Slide 21

1. Material Properties

Ex [GPa] 132

Ey [GPa] 8.9

v_x 0.31

Es [GPa] 5.6

2. Load & Boundary conditions

P=100 Pa

Uy = 0

X

ZY Local CSYS

Y — Fiber direction

Z — Thickness direction

[± 90]m

Composite

Cylinders

Analysis of Composite Cylinder under Internal Pressure

ID=0.4 m

OD=0.7m

Height=0.6m

Slide 22

FEXL

ABAQUS

Path for plot

Analysis of Composite Cylinder under internal Pressure

Radial disp. vs radius

0

2E-10

4E-10

6E-10

8E-10

1E-09

1.2E-09

1.4E-09

0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75

stre

ss

r

FEXL ABAQUS

P=100 Pa

[± 90]mID=0.4 m

OD=0.7m

Height=0.6m

Slide 23

FEXL

ABAQUS

Path for plot

Analysis of Composite Cylinder under internal Pressure

σθθvs r

0

50

100

150

200

250

300

350

400

0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75

stre

ss

r

ABAQUS FEXL

P=100 Pa

[± 90]mID=0.4 m

OD=0.7m

Height=0.6m

Slide 24


Ex [GPa] 132

Ey [GPa] 8.9

nu_x 0.31

Es [GPa] 5.6

2. Loads & Boundary conditions

Angular Velocity:

ω =100 rpm

ω

ID=0.4 m

OD=0.7m

Height=0.6m

Analysis of Composite Cylinder in Rotation (Flywheel Rotor)

Uy = 0X

ZY Local CSYS



[± 90]m

Composite

Cylinders

Slide 25

FEXL

ABAQUS

Path for plot

1.70E-07

1.90E-07

2.10E-07

2.30E-07

2.50E-07

0.4 0.5 0.6 0.7

Dis

pla

cem

en

t

r

FEXL ABAQUS

ω =100 rpm

[± 90]m ID=0.4 m

OD=0.7m

Height=0.6m



Slide 26

σθθvs r

4.60E+04

4.80E+04

5.00E+04

5.20E+04

5.40E+04

5.60E+04

5.80E+04

6.00E+04

0.4 0.45 0.5 0.55 0.6 0.65 0.7

Str

ess

r

FEXL ABAQUSFEXL

ABAQUS

Path for plot


ω =100 rpm

[± 90]m ID=0.4 m

OD=0.7m

Height=0.6m

Slide 27

Section

Cross section

Composite Spherical Cap

[+q/-q]m

FEA

FEM Model

Analysis of Composite Spherical Cap

Slide 28


Ex [GPa] 132

Ey [GPa] 8.9

nu_x 0.31

Es [GPa] 5.6


Analysis of Composite Spherical Cap under internal Pressure

[± 90]m

ID=2 m

OD=2.15m

Angle_s=0

Angle_f=90

P = 100 Pa

Ux = 0

Uy = 0

Global CSYS X

ZY

Local CSYS-m

X

ZY

X

ZY

Local CSYS-1

Local CSYS-n



Slide 29


0.00E+00

5.00E-08

1.00E-07

1.50E-07

2.00E-07

2.50E-07

3.00E-07

3.50E-07

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

Dis

pla

ce

me

nt

r

FEXL ABAQUS

[± 90]m ID=2 m

OD=2.15m

Angle_s=0

Angle_f=90

P=100 Pa


FEXL

ABAQU

S

Path for plot

Slide 30


-1500

-1000

-500

0

500

1000

0 0.5 1 1.5 2S

tre

ssr

ABAQUS FEXL

σθθvs r

[± 90]m ID=2 m

OD=2.15m

Angle_s=0

Angle_f=90

P=100 Pa

FEXL

ABAQUSPath for p

lot

Slide 31


Ex [GPa] 132

Ey [GPa] 8.9

nu_x 0.31

Es [GPa] 5.6


Analysis of Composite Spherical Cap in Rotation

ID=2 m

OD=2.15m

Angle_s=0

Angle_f=90Ux = 0

Uy = 0

Global CSYS

ω

Angular Velocity:

ω=100 rpm

X

ZY

Local CSYS-m

X

ZY

X

ZY

Local CSYS-1

Local CSYS-n



Slide 32

8.00E-06

9.00E-06

1.00E-05

1.10E-05

1.20E-05

1.30E-05

1.40E-05

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2

Dis

pla

ce

me

nt

r

FEXL ABAQUS

32

Analysis of Composite Sphere in Rotation

ω =100 rpm

[± 90]m ID=0.4 m

OD=0.7m

Height=0.6m


FEXL

ABAQUS

Path for p

lot

Slide 33

Analysis of Composite Spherical Cap in Rotation

0.00E+00

1.00E+05

2.00E+05

3.00E+05

4.00E+05

5.00E+05

6.00E+05

7.00E+05

8.00E+05

0 0.5 1 1.5 2

Str

ess

r

FEXL ABAQUS

σθθvs r

ω =100 rpm

[± 90]m ID=0.4 m

OD=0.7m

Height=0.6m

FEXL

ABAQUS

Path for plot

Slide 34

Analysis of Cylindrical Pressure Vessel for Various Angles

-2

0

2

4

6

8

10

12

0 10 20 30 40 50 60 70 80 90

sig_y (transverse direction)

analytic (thin)FEXL

0

2E-10

4E-10

6E-10

8E-10

1E-09

1.2E-09

1.4E-09

0 10 20 30 40 50 60 70 80 90

Disp_1(radial displacement)

FEXL

analytic (thin)

x

z

y

x

”

z”

y”

x’

y’

x”

y”

q

q

Fiber angle, q

Fiber angle, q

[q/-q]m

Slide 35

Dimension input for pressure vessel

Analysis of Pressure Vessel


Transverse stress vs radius

P = 100Pa

Analysis of 2D Triaxial Braided Textile Composites & FEXL · 2012-03-08 · Slide 3 Introduction to...

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