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Modelling of nonwoven materials

Stepan V. Lomov, Amit Rawal

Department Metallurgy and Materials Engineering, KULeuven

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NoWoTex: Specs

Fibrous assembly: Non-woven fabric Fibrous components

Fibrous componentsFibre properties

Length

Waviness and curvature

Orientation

Fabric weight & thickness

Fibre content

Random realisationRandom realisationRandom realisationRandom realisation

Geometry & Visualisation

Contacts and links

Permeability

Properties of composite

Mechanical properties

Bonding

Individual properties of the

realisation and Monte Carlo for the

assembly

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NoWoTex: GUI

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Input: Fibreproperties

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FibrepropertiesEASTLON SN-3250CM HC SL hygienic

Material PES PESLinear density, tex 0.22 0.33Density, g/cm3 1.38 1.38Diameter (computed), mm 0.0142 0.0174Friction coefficient (ASSUMED) 0.3 0.3Young modulus, GPa 11 11Poisson ratio 0.25 0.25Tenacity, cN/dtex 3.4 3.7

MPa 469 511Elongation, % 60 57Length, mm 51 57

Proportion, wt% 50 50

Areal density, g/m2 27.6Thickness, mm 0.5Vf_total, % 4.0

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Input: Fibre length

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Input: Fibreorientation

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Measurements of the fibreorientation

TI

x

y

z

2

1

3p

p1 p

2

p3

� � � �� �

� �� �int

1

;cos

, 1...cos

i

ii

ii

is

k

k ds i N

�

3

< 3< �§ ·< 3¨ ¸ ¨ ¸�© ¹³

ff

f

INTf

ff n

f

f n

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Input: Fibrewaviness

1 1 2 2 2( ) sin sins s

s A n nL LS S\ \§ ·§ · § · � � �¨ ¸¨ ¸ ¨ ¸© ¹ © ¹© ¹1r r r

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Material

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Contacts

Total contacts: 1509; 693 contacts/mm3[EASTLON SN-3250CM]x[EASTLON SN-3250CM]: 142; 65 contacts/mm3[EASTLON SN-3250CM]x[HC SL hygienic]: 777; 357 contacts/mm3[HC SL hygienic]x[HC SL hygienic]: 590; 271 contacts/mm3

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Contact types

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Orientation averaging of the fibre tension

E

’fl

fl

Esinfl

Ecosfl

EH cosfl

O A

B

CB’A’

A

D

Dbb

1 DA

MachineDirection

F_fibre

Poisson

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� � � �� �

11 1 1

11

22 2 2

12

cos ( ) ( , )

cos ( ) ( , );

nf

a i i iif

nf

a i i i i iif

mT K

mK

OD M D F M D V E HUO M D F M D V E H E M DU

� � � �

� � � � �¦¦

Equationsweb stress per unit width [N/m] for the test direction D

component fraction

mass per unit area

directional parameter: fiber length projection on the test direction.

fibre orientation angle

frequency of the orientation

fibre stress

fabric strain

� �> @1sin)1()1(cos)(2/12222 ���� EQHHEHV ff f

f

fibre strain Poisson ratiofibre tension diagram

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Input: Components and arealdensity

T17T17

T28

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Input: Fibre orientation

0.00110.080.0440.1590°

0.500.430.430.3467.5°

0.930.880.830.7845°

1.211.191.131.1022.5°

1.311.331.221.260°

124.43.32.2

T28T17DK(D)

a

00.020.040.060.080.1

0.120.140.16

-90 -70 -50 -30 -10 10 30 50 70 90

Fibre Orientation Angle (o)

Rel

ativ

e Fr

eque

ncy

b

0

0.02

0.04

0.06

0.08

0.1

0.12

-90 -70 -50 -30 -10 10 30 50 70 90

Fibre Orientation Angle (o)

Rel

ativ

e Fr

eque

ncy

T17

In-plane fibre orientation: approximated by normal distribution

a=17.72

b=18.99

T = 21º

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Input: Fibre tension

0

1

2

3

4

5

6

7

0 2 4 6 8 10 12

Strain (%)

Str

ess

(cN

/tex)

2.2 dtex

3.3 dtex

4.4 dtex

12 dtex

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Input : Poisson ratio

0

2

4

6

0 1 2 3 4 5 6 7 8

Longitudinal Strain (%)

Poi

sson

’s R

atio 0°

22.5°

45°

67.5°

90°

00.5

11.5

22.5

33.5

4

0 1 2 3 4 5 6 7 8

Longitudinal Strain (%)

Poi

sson

’s R

atio

0°

22.5°

45°

67.5°

90°

T17T28

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Results: Diagrams

00.10.20.30.40.50.60.7

0 1 2 3 4 5 6 7 8

Strain (%)

Str

ess

(N/m

m)

Experimental

Incl. Poisson’s Ratio

Excl. Poisson’s Ratio

0

0.2

0.4

0.6

0.8

1

0 1 2 3 4 5 6 7 8

Strain (%)

Str

ess

(N/m

m)

Experimental

Incl. Poisson’s Ratio

Excl. Poisson’s Ratio

0

0.02

0.04

0.06

0.08

0.1

0.12

0 1 2 3 4 5 6 7 8

Strain (%)

Str

ess

(N/m

m)

Experimental

Incl. Poisson’s Ratio

Excl. Poisson’s Ratio

0

0.02

0.04

0.06

0.08

0.1

0 1 2 3 4 5 6 7 8

Strain (%)

Str

ess

(N/m

m) Experimental

Incl. Poisson’s Ratio

Excl. Poisson’s Ratio

T17 T28

0°

67.5°

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Results: Modules

02468

101214161820

0 22.5 45 67.5 90

Test Angle (o)

Sec

ant M

odu

lus

(MP

a)

Experimental

Incl. Poisson’s Ratio

Excl. Poisson’s Ratio

0

5

10

15

20

25

30

0 22.5 45 67.5 90

Test Angle (o)

Sec

ant M

odul

us (M

Pa) Experimental

Incl. Poisson’s Ratio

Excl. Poisson’s Ratio

T17

T28