Composite Materials Group Composites on meso macro level · Composites on meso - Macro level:...

Composite Materials Group

Composites on meso –

macro level

Stepan V. Lomov

2

Contents

• Research objectives

• State-of-the-art 2014

• Research perspectives 2015 and beyond

3




4

Hierarchy of structural levels in composite materials: nano

icro

Chowdhury 2007

5

Hierarchy of structural levels in composite materials: icro

meso

Mishnaevsky 2009

Goyal 2008

6

Hierarchy of structural levels composite materials: meso

Macro MEGA

7

Composites on meso - Macro level: Research objective

1. Theoretical understanding, experimental study and formalisation into models

and design tools of the mechanical behaviour of (nano-engineered) fibre

reinforced composites (n)FRC:

• during manufacturing

• in-service performance

2. Optimisation of (n)FRC and development of novel materials with high

mechanical properties, toughness and damage tolerance.

8

Composites on meso - Macro level: Subject definition

Structural levels: (nano) – micro – meso – Macro

Materials:

1. Fibre reinforced composites (FRC) in general, including nano-

engineered (nFRC) with the emphasis on:

• Textile composites

• Random fibre reinforced composites

2. Heterogeneous materials in general, with forays towards porous and

biomaterials

Properties:

1. Internal architecture/structure/geometry, hierarchial organisation

2. Mechanical properties and behaviour, including:

• Quasi-static response (elastic properties, non-linearity)

• Fatigue

• Damage initiation, progression, resistance and tolerance

9

Composites on meso - Macro level: Materials of special interest

Material type Motivation Typical structure

Woven laminates “Guinea pig” for new developments in

matrices, fibres, nano-reinforcements …

Tri-axial braids Quasi-isotropic

Crash resistant

3D woven: non-

crimp

Best realisation of fibre properties

No delaminations

3D woven: angle

interlock

Net shape

No delaminations

Energy absorption

3D braids Beams

Energy absorption

Non-crimp fabrics

(NCF)

Cheap

Best realisation of fibre properties

Structurally stitched No delaminations

Random fibre

composites

Cheap and formable

10

Composites on meso - Macro level: Research philosophy

1. Focus on the material; applications

via partnerships.

2. Behaviour of a composite can be

understood only if research spans

several structural levels.

3. Performance of a composite can be

understood only if manufacturing is

considered as well.

4. Experimental study should lead to a

descriptive, better predictive model.

5. Model development should lead to a

numerical tool.

6. Fundamental studies should

understand about real behaviour and

applications.

7. Applied studies should understand

about fundamental phenomena.

11

S.V.Lomov - Singapore - May 2010 11

Integrated design tool for textile composites

x

z

p

h z(x)

Q

Q

d2

d1

Z

A

B

Internal architecture of the reinforcement

Deformation resistance and change of

geometry

Compr. Shear Tension Bending

Permeability

M

R=1/

K

Drapeability and formability

Impregnation

Production

Mechanical properties

and damage

Performance

Structural analysis

12



1. Models of textile composites: – WiseTex

– Method of inclusions

– Integration with PAM-SYSPLY

– meso-FE: homogenisation, embedded elements, micro-CT

– meso-FE: damage

2. Textile reinforcements:

3. Mechanical properties and damage:

4. Materials of special interest:


WiseTex: Virtual textiles/composites

Internal geometry: textile unit cell

x

z

p

h z(x)

Q

Q

d2

d1

Z

A

B

WiseTex

LamTex

WeftKnit

woven (2D and 3D) braids

weft-knits NCF laminates

Virtual reality

VRTex

meso-FE

WiseTex -> Ansys

(FETex)

WiseTex -> Abaqus

Composite micromechanics (fast stiffness calculations)

TexComp

Permeability

FlowTex

13

WiseTex worldwide

licenses:

industrial (12)

university (37)

14

15

Method of inclusions

G. Huysmans 2000 … G. Perie 2009

1C m s s s

m s m sc c c c

C C C A I A

Eshelby solution

Mori-Tanaka homogenisation

Excellent results for complex textile composites (and random fibre composites)

TexComp

Iso-strain

Random fibres: Stresses in inclusions

16

a11= 0.52; a22 = 0.48

Vf = 0.25

Applied strain = 0.1

Average stress in the inclusion phase

FE MT

S11 1042.5 MPa 1010.4 MPa

S22 -73.1 MPa -54.5 MPa

A. Jain 2013

17

17

Integration WiseTex – SYSPLY

WiseTex

Local deformation

parameters

(thickness, shear…)

Forming:

QUIKFORM

Internal

geometry

Local stiffness [Q]

FE analysis:

SYSPLY

Stress/strain fields

TexComp

18

meso-FE: Road map

Geometric modeller

Geometry corrector

Meshing

Assign material properties

Boundary conditions

FE solver, postprocessor

Homogenisation

Damage analysis

N+1 N

N+2

19

SACOM,

ABAQUS,

ANSYS…

MeshTex

WiseTex

WiseTex – MeshTex/SACOM – commercial FE packages

State-of-the-art numerical tool for preparation of FE models and FE analysis of textile composites on meso-structural level

Geometric modeller

Geometry corrector

Meshing

Assign material properties

Boundary conditions

FE solver, postprocessor

Homogenisation

Damage analysis

University of Osaka, Prof M. Zako

Transformation into FE model

WiseTex

Abaqus

Python script

20 D.S. Ivanov, S.A. Tabatabaei 2013

Embedded elements

Validation on different scales

21 S.A. Tabatabaei 2014

µCT – voxel FE model

Anisotropy0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

Density

130

135

140

145

150

155

160

165

1

10

210

matrix

yarns

segmentation and identification of local fibre directions

22 I. Straumit 2014

23

Damage in textile composites: Standard stiffness degradation

scheme Stiffness degradation scheme: generally accepted …

real damage: transverse cracks, propagating along braiding yarns … leads to unphysical direction of

propagation of damage: across the fibres inside the yarns

damage zone

D. Ivanov, L. Gorbatikh 2007

24

Advanced damage model …

1) Elementary damaged entity: segment

2) Orientation of the failure plane: Mohr-Hashin-Puck concept

3) Degradation scheme

4) Damage evolution law:

5) Combination: micro/plasticity and damage

Crack plane defines the orientation of degradation

crG

Ydd ~

2

Yarn segment: fibre orientation is constant

Damage energy release rate

)12(

)11(2

12

12

2d

dd

2d

12d

2

2

0

22 )1( dEE )1( 12

0

1212 dGG

)1( 2

0

1212 dvv )1( 2

0

2323 dvv

D. Ivanov, 2009

25

… brings good predictions (example: 3-axial braid)

experimental damage initiation

Damage development (shear degradation parameter d12) in MD tensile test

Principal levels of applied strain and stress at failure: 1 - damage initiation; 2 –crack density increase (delamination onset); 3 – ultimate failure;

D. Ivanov, 2009

26



1. Models of textile composites

2. Textile reinforcements – Internal geometry

– Deformability

– Permeability

3. Mechanical properties and damage:



27

Internal geometry of textile reinforcements: WiseTex

S.V.Lomov, 1999 …

x

z

p

h z(x)

Q

Q

d2

d1

Z

A

B

min

,,,

kljWe

jlk

We

jl

We

jlk

We

jlk

We

jlk

kiWa

ik

Wa

ik

Wa

ik

Wa

ik

Wa

ik

p

hF

p

B

p

hF

p

BW

minimum of bending energy + compressibility of yarns

decomposition of the problem + characteristic functions

28

Internal geometry of textile reinforcements: Experimental

studies

D. Ivanov, 2007

Nesting, yarn dimensions and distribution of the fibres

Visualisation and µCT validation

29

µCT: examples

30

Measurements on a µCT image

31

J. Pazmono 2013

Variability of the yarn paths and dimensions

32

Periodic, systematic variations

Non-periodic, stochastic deviations

Long range

Short range

A. Vanaerschot, B. Cox 2013

33

Materials studied 2000 – 2014: internal geometry

Fibres/matrix Reinforcement Publication

carbon/epoxy NCF 0/90, ±45 Comp A 33: 1171 (2002)

NCF tufted with carbon yarn Adv Comp Lett 15: 87 (2006)

Bi- and tri-axial braids Text Res J 72: 706 (2002)

3D woven 3Tex Comp A 41: 1301 (2010)

Hexcel twill 2/2, variability Comp A 44: 122 (2013)

Computers and Struct 122: 55 (2013)

Plain weave Polymer Composites 33: 1335 (2012)

glass/epoxy Plain weave Comp Sci Techn 60: 2083 (2000)

Comp Sci Techn 63: 993 (2002)

3D woven 3Tex Comp Sci Techn 65: 1920 (2005)

Comp B 65: 146 (2014)

glass, steel weft-knitted Text Res J 85: 500 (2014)

34

Deformability of textile reinforcements: WiseTex models

S.V.Lomov, 2001 …

Compression

Uni- and Biaxial tension

Shear

(un)bending + compression of yarns

work of compressive force Q on change of thickness db = change of bending energy of yarns dW

d2Wa

d2We

q

d1Wa

d1We

Qij

T T

Q

h

Wa

p

• Friction between the yarns • Lateral compression of the yarns • (Un) bending of the yarns • Torsion of the yarns • Vertical displacement of the yarns T

T Q

35

Deformability of textile reinforcements: Experimental studies

Biaxial tensile tester

0

0.004

0.008

0.012

0.016

0 0.5 1 1.5 2Elong [%]

Fo

rce [

kN

/mm

]

1:1 2:1

5:1

1:2

1:5

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

0 10 20 30 40 50

Shear angle, °

Sh

ear

forc

e,

N/m

m

shear

optical (DIC) registration of the fabric shear

S.V.Lomov, A. Willems 2004 …

36

Shear: Benchmarking exercise

plain weave Twintex

picture frame

37

Draping, formability and modelling

FE kinematic

K. Vanclooster 2008

Change of geometry due to shear

38

Cross section of warp yarns on sagittal plane

Cross section of weft yarns on transaxial plane

M. Barburski 2014

Forming studies

39 J. Pazmino 2014

Deformability and formability

40

in-situ thickness laser measurements on picture frame (KU Leuven)

yarn compressibility tester (KU Leuven)

picture frame test in thermal camera (KU Leuven)

micro-scale forming (KU Leuven)

KU Leuven lab is fully equipped for characterisation of reinforcements for forming simulations

Identification of a material model

41

0

0.002

0.004

0.006

0.008

0.01

0.012

0.014

0 10 20 30 40 50

Shear angle, °

Sh

ear

forc

e,

N/m

m

baseline fabric

0.25

0.3

0.35

0.4

0.45

0.5

0 0.05 0.1 0.15 0.2 0.25

p, MPa

h1

, m

m

1 ply cycle 1

1 ply cycle 2

1 ply cycle 3

4 plies cycle 1

4 plies cycle 2

4 plies cycle 3

tension

shear

bendin

g

compaction

K. Vanclooster, M. Barburski 2013

42

Forming diagram for multi-layered preforms

K. Vanclooster 2009

0° 45°

Formability of multi-layered composites

– Depends on the relative orientation between neighbouring plies

– Depends on friction between the plies (PP-interlayer thickness)

measurement of interply friction for thermoplastics and FE modelling

43

Materials studied 2000 – 2010: Deformability

Fibres Reinforcement Publication

carbon NCF 0/90, ±45, 0/45/-45/90 Comp A 34: 359 (2003)

Comp A 36: 1188 (2005)

Twill weave with and without grafted

carbon nanotubes

Comp Sci Tech 71: 315; 1746 (2011)

Carbon 49: 2079; 4458 (2011)

Comp A 64: 167 (2014)

glass Plain weave J Reinf Plast Comp 19: 1329 (2000)


Text Res J 76: 243 (2006)

3D woven Comp Sci Techn 73: 9 (2012)

Comp A 61: 76 (2014)

Comp B 65: 146 (2014)

Twintex Plain weave

Twill



Comp A 39: 1037 (2008)

steel Knitted Key Eng Mat 42: 16 (2012)

Key Eng Mat 43: 554 (2013)

alumina (Al2O3) Plain weave with grafted carbon

nanotubes


flax Quasi-UD weave Key Eng Mat 611: 257 (2014)

44

Permeability of textile preforms: Simulations

pΚ

gradv

p = 0

<u>

<u>

p = p

A

A´

B. Verleye 2008

1st International Permeability benchmark

Balanced Carbon twill 2x2 (G986) Unbalanced Glass twill 2x2 (G1113)

45

2007 – 2010

2nd International Permeability Benchmark

46

2011 – 2013

Ecole Polytechnique Montreal

47

Materials studied 2000 – 2014: Permeability

Fibres Reinforcement Publication

carbon NCF 0/90, +45/-45 SAMPE Europe 2003

Twill 2/2 Comp A 42: 1157 (2011)

Comp A 61: 172 (2014)

glass Plain weave Comp A 35: 1407 (2004)

Comp A 42: 1157 (2011)

NCF 0/90 Adv Comp Lett 18: 121 (2009)

n/a Stereolithographic reference medium Comp A 40: 244 (2009)

48



1. Models of textile composites:

2. Textile reinforcements:

3. Mechanical properties and damage: – Damage monitoring during test and post-mortem

investigation

– Fatigue



49

Motivation: early damage initiation in textile composites

stress

AE

strain, % No stiffness reduction up to failure

Early damage initiation

Design strain at 0.3 ... 0.4%

Ratio Ultimate strain / Design strain of 4...5

50

AE and DIC monitoring of damage

S.V. Lomov 2008

objective characterisation of te progressive damage

51

Experimental road map

Textile preparation (shear...), measurements

Impregnation(RTM...)

X-Ray of the unloaded samples

Tension test with AE, strain-mapping

Identification of 1, 2, 3

Tensile tests till 1, 2, 3

C-scan

X-Ray

Cutting according to the crack pattern

Analysis of the cracks on micrographs

Tension diagrams

AE diagrams

Strain maps

Dynamics of damage extent

Damage periodicity

Cracks placement and orientation

Crack length distribution

Damage initiation threshold

Cutting the samples in characteristic directions

Thermal/cure damage characterisation

Architecture of the textile

Fine structure of damage

SEM at the selected positions Micro-characterisation of damage modes

Study of the reinforcement geometry

S.V. Lomov 2008

52

Damage development: glass/epoxy

at failure (2.7%)

S.V. Lomov 2010

53

Damage development:

carbon/epoxy

A: Sporadic cracks on yarn boundaries

B: Well-developed system of transversal cracks and cracks on boundaries of the yarns; sporadic transversal matrix cracks

U: Massive transversal cracks; local debondings on the boundaries of the yarns and matrix cracks parallel to the sample surface

M. Karahan, A. Bogdanovich 2013

AE cluster analysis

54

A, dB

frequency parameter, kHz

1. “Ternary” clusters pattern is the same for 2D and 3D woven composites, glass and carbon

2. Frequency boundary is the same for 2D and 3D, but different for glass and carbon.

3. Amplitude boundary is the same for 2D and 3D woven composites, glass and carbon

4. The A and F cluster boundaries are consistent with literature and with the hypothesis:

• FH = fibre breakage

• ALFL = inter-fibre matrix cracks

• AHFL = delaminations

ALFL

AHFL

FH

L. Li 2014

55

Materials studied 2005 – 2010: Progressive damage


Experimental methodology in general Comp Sci Tech 68: 2340 (2008)

carbon/epoxy NCF 0/90, ±45, 0/-45/90/45 Comp A 36: 1207 (2005)

NCF ±45, sheared Comp A 39: 1380 (2008)

NCF 0/90, ±45, toughened resin Comp A 40: 251 (2009)

NCF tufted with carbon yarn Comp Sci Tech 69: 2701 (2009)

3-axial braid Comp Sci Tech 69: 1373 (2009)

Uniaxial braid Comp Sci Tech 68: 2340 (2008)

Uniaxial weave tufted with carbon Plast Rubb Comp 38: 98 (2009)

Woven twill 2/2 with carbon nanotubes Carbon 49: 4650 (2011)

Comp A 42: 1835 (2011)

3D woven 3Tex Mech Mater 62: 14 (2013)

Text Res J 84: 1373 (2014)

3D braided 3Tex ECCM-14 (2010)

carbon/PPS 5H satin Comp Sci Techn 71: 1171;1217 (2011)

glass/epoxy Plain weave Comp A 40: 1134 (2009)

Comp A 40: 1144 (2009) 3D woven 3Tex

Plain weave Compos Struct 116: 286 (2014)

56

Tension-tension fatigue: S-N curve and progressive damage

0

50

100

150

200

250

300

350

400

450

500

1.E+00 1.E+01 1.E+02 1.E+03 1.E+04 1.E+05 1.E+06 1.E+07

I

II

III

stress, MPa

number of cycles

time

stre

ss

max

min K. Vallons, 2007 …

in collaboration with V. Carvelli, Milano

57

Damage development:

carbon/epoxy

10,000

100,000

1,000,000

M. Karahan 2013

58

Fatigue limit vs damage initiation threshold

_min: first AE event

_1: damage initiation

_2: initiation of high energy damage events

_ULT: failure

NCF carbon/epoxy, stitched

NCF carbon/epoxy

NCF carbon/epoxy, unstitched

plain weave glass/epoxy

3D glass/epoxy

carbon/epoxy braid

3D carbon/epoxy

59

Materials studied 2007 – 2010: Fatigue


carbon/epoxy NCF 0/90 Comp A 38: 1603 (2007)

NCF 0/90, ±45, toughened resin Comp A 40: 251 (2009)

Comp A 42: 16 (2011)

NCF 0/90 Comp Sci Tech 70: 2216 (2010)

NCF tufted with carbon yarn

Woven twill 2/2 ICCM-17 (2009)

3D woven 3Tex Comp Sci Techn 71: 1961 (2011)

3D braided 3Tex J Compos Mat 47: 3188 (2013)

carbon/PPS 5H satin Comp Sci Techn 74: 20 (2013)

glass/epoxy Plain weave Comp Sci Tech 70: 2216 (2010)

3D woven 3Tex

Quasi-UD NCF Mech & Industry 14: 175 (2013)

Comp A 56: 272 (2014)

short glass,

steel fibre /

termoplasts

straight glass fibres

wavy steel fibres

ECCM-16

60



1. Models of textile composites

2. Textile reinforcements

3. Mechanical properties and damage

4. Materials of special interest: – 3D non-crimp woven composites

– 3D angle interlock composites

– Non-crimp fabrics

– Structurally stitched composites

– Random fibre reinforced composites

– Steel fibre textiles


61

3D woven non-crimp composites: Glass/epoxy

in collaboration with A. Bogdanovich,

3Tex and V. Carvelli, Milano

comparative study: plain weave laminate vs 3D woven composite

3D 2D

62

3D woven non-crimp composites: Carbon/epoxy

in collaboration with A. Bogdanovich, 3Tex,

M. Karahan, Bursa and V. Carvelli, Milano

detailed study of internal geometry

non-Hookean tensile behaviour

0

100

200

300

400

500

600

700

800

900

1000

0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6

strain, %

str

ess,

MP

a

0

10

20

30

40

50

60

70

80

90

100

E,

GP

astress, fill

E, fill

damage progression and fatigue

AE

S-N

63

3D woven non-crimp composites: FE modelling

63

• correct modelling of degradation

of stiffness

• reasonable evaluation of damage

initiation threshold

• qualitative representation of

intensity of damage

Resolution of yarn interpenetrations 1

2

3

p01

p11

p02 p12

s1

s2

p01

p11 s1 s2

p01=p11

P02=p12

s1

s2

p01=p11

6 2 3 4 5 7

1 6

2 3 4 5 7

1

64 E. Bedogni 2013

65

3D angle interlock composites

G. Perie, 2010

WiseTex model: excellent predictions of the stiffness

1 m

66

3D textiles 1995 – 2014

Material Properties Publication

General 3D weave Coding of the weave Technische Text 38: 20 (1995)

Modelling Text Res J 81: 26 (2011)

3D woven, carbon/epoxy Stiffness Comp Sci Tech 60: 2083 (2000)

3Tex, glass/epoxy Internal geometry Comp Sci Tech 65: 1920 (2005)

Stiffness, strength Comp A 40: 1134 (2009)

Damage Comp A 40: 1144 (2009)

Fatigue Comp Sci Techn 70: 2068 (2010)

3Tex, carbon/epoxy Internal geometry Comp A 41: 1301 (2010)

Stiffness, strength, damage Mech Mater 62: 14 (2013)

Text Res J 84: 1373 (2014)

Fatigue Comp Sci Techn 71: 1961 (2011)

3D angle interlock,

carbon/epoxy

Internal geometry

Stiffness

ICCM-17 (2009)

Text Res J 81: 1 (2011)

3D braided Damage J Compos Mat 47: 3188 (2013)

67

NCF: Internal geometry

S.V. Lomov, 2002; R. Loendersloot, 2005

Distortions of fibrous plies due to stitching

change of geometry in a sheared fabric

68

NCF: Deformability and permeability

Biaxial -45/+45 MD/CD

0

0.004

0.008

0.012

0.016

0.02

0 0.5 1 1.5 2Elong [%]

Fo

rce [

kN

/mm

]

forming

shear (picture frame) and biaxial tension

permeability

S.V. Lomov, 2002, 2005

69

NCF: Mechanical properties, damage and fatigue

Truong, 2005, 2008; Mikhaluk 2008; Vallons 2008, 2009, 2010

MD

Damage initiation and development is linked to the stitching sites

S-N fatigue curves and development of cracks during fatigue

70

Structurally stitched reinforcements

Koissin 2006, 2009

internal geometry and WiseTex model

correlation between damage

and stitching

sites

71

A book @ Woodhead Publishers, 2011

72

NCF and structurally stitched 2000 – 2010


Carbon/epoxy NCF Internal geometry Comp A 33: 1171 (2002)

Comp A 37: 103 (2006)

Deformability Comp A 34: 359 (2003)

Comp A 36: 1188 (2005)

Permeability SAMPE-Europe 2003

Mechanical properties, damage Comp A 36: 1207 (2005)

Comp A 39: 1380 (2008)

Fatigue Comp A 38: 1633 (2007)

Comp A 40: 261 (2009)

Comp A 42: 16 (2011)

Impact and post-impact Comp A 41: 1019 (2010)

FE modelling Eng Fract Mech 75: 2751 (2008)

Comp A 39: 1380 (2008)

Glass/epoxy NCF Machanical properties and fatigue Mech & Ind 14: 175 (2013)

Comp A 56: 172 (2014)

Structurally stitched Internal geometry Adv Comp Lett 15: 87 (2006)

Mechanical properties, damage, FE

damage

Plast Rubb Comp 38: 98 (2008)

Comp Sci Tech 69: 2701 (2009)

Fatigue Comp Sci Tech 70: 2216 (2010)

73

Random fibre reinforced composites

Jao Jules 2005

5% 4 3 1 2

Successful use of inclusions method for prediction of stiffness and onset of debonding

Short wavy steel fiber composites

• Short steel fiber composites are novel

material combining outstanding properties

of stiffness and ductility.

• Typically used for improved shielding

properties of polymers.

• Processing of injection molded short steel

fiber composites leads to significant fiber

waviness.

VF 0.5%

VF 2%

Very dense and wavy

structures at low

volume fractions

Y. Abdin 2014

Geometrical modelling of short

wavy steel fiber composites

Model:l

Micro-CT characterization for determination of geometrical

parameters

Wavy fiber modelled with 2 parameter harmonic

functions

Y. Abdin 2014

Validation: RVE of SSFRC

• Application of the inclusion model on RVE of wavy steel fibers, comparison

with FE.

• “Real” fibers extracted from micro-CT data.

• Homogeneous fiber cross-sections.

FE model

= 2273365 elements Model shows very good predictions compared to FE.

Y. Abdin 2014

Flow chart of proposed algorithm

77

0 Read Input SN data – stress level and

corresponding number of cycles

Calculate Initial Young’s modulus E0 – MT

formulation

Calculate the modulus and damage

parameter at stress level, S1 read from SN

curve

For second RVE: loading increments is

modelled and the modulus and damage

parameter is calculated

σ

ԑ

E0

Dfirstcycle = 1-E1/E0

Stress at which damage parameter

Dfirstcycle is reached, S2 is the stress to

failure for initially choosen cycles

S1

N

SN-ref

S2

ԑ

E02

E12

Dfirstcycle = 1- E1RVE / E0

RVE

1

1

2

2

3 3

4 4

5 5

Fiber Matrix debonding in RFRC

78

1. Debonded inclusions are replaced by fictitious “EqBI”

2. FE based validations confirm that the average stresses in inclusions for different debonded lengths are accurate

3. Also one is able to track correctly the stresses in the interface by combination of the Mori-Tanaka formulation and Cox Model

1

2

3

Experimental validation

79

Good results for scaling irrespective of the input SN-curve

Two points are usually enough for scaling linear SN-curves

Only one SN-curve was enough to predict the fatigue properties for other points

A. Jain 2014

80

Short fibre composites 2000 – 2014


Genearl Modelling Comp Sci Techn 87: 86 (2013)

Glass / thermoplast Mechanical ICCM-15 (2005)

Micromechanics, damage TexComp-11, 2013

Fatigue ECCM-16, 2014

Steel / thermoplast Geometry Comp A 67: 171 (2014)

Micromechanics ECCM-16, 2014

81




Short fibres

82

2013 – 2014 2014 – 2015

Finalise the fatigue scaling Toolset: fatigue scaling

Experimental validation Toolset: fatigue micro-analiser

Include in LMS macro-model Validation fatigue micro-analiser

Start fatigue micro-analyser

Start experimental program on steel and

glass fibres

Internal geometry

83

2013 – 2014 2014 – 2015

Finish variability models Start variability for natural fibres

Finish µCT-Abaqus (voxels) Release VoxTex

WiseTex – Abaqus Finish µCT for flax

Release CIVATex Release FETex 2.0

Deformation and geometry Geometry Dry Tape Laying

µCT = “standard” tool

Deformability

2013 – 2014 2014 – 2015

In-depth high T° steel Compressibility of nano-veils

Finalise forming modelling Validation of meso-FE

Formability flax

Thickness laser on biaxial tester

84

Permeability

2013 – 2014 2014 – 2015

Participation in the International

benchmark

Release VoxTex with FlowTex link

Benchmark FlowTex vs ANSYS Submit C2 project on permeability

µCT – voxels – FlowTex

85

Damage and meso-FE

2013 – 2014 2014 – 2015

In-situ microscopy Embedded elements

Self-reinforced materials Damage in meso-FE

Hybrid textiles XFEM for textile composites

Embedded elements AE analysis

Damage in meso-FE Telene matrix

AE analysis Inclusion model for damage

Telene matrix Damage Dry Tape Laying

Micro-macro damage

Damage Dry Tape Laying: Stepan, Nghi Effect of defects

86

Fatigue

2013 – 2014 2014 – 2015

Models for short fibres Toolset: fatigue short fibres scaling

Experimental data short fibres Toolset: fatigue short fibres micro-analiser

Experimenatal data glass/CNT Micro-macro fatigue

Effect of defects

87

Software

88

2013 – 2014 2014 – 2015

New licenses and collaborations release FETex 2.0

Software µCT – Abaqus release VoxTex

start collaboration MeshTex

Composite Materials Group Composites on meso macro level · Composites on meso - Macro level:...

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