m3 program accelerating the engineering process: from ......06 june 2017 23/# dept. of materials ,...

Prof. Wim VAN

PAEPEGEM06 June 2017 1/#

Dept. of Materials , Textiles

and Chemical Engineering

Partners:

M3 program – accelerating the

engineering process: from materials to

applications

Twin M3Strength projects

Prof. Wim VAN




• M3 Program and addressed domains in the twin M3Strength

projects

• Key R&D details of the twin M3Strength projects and related

industrialization1. Composites fatigue modelling

2. Quasi-static and dynamic multi-scale modelling

3. Effect of defects by multi-scale modelling

4. Composites dynamic modelling for crash and crush

• Summary

Outline

Prof. Wim VAN




Knowledge centers

Industry

Solving lightweight

challenges

by

advanced testing

& simulation

M3 MacroModelMat program

Prof. Wim VAN




Twin projects “M3Strength”

Multi-attribute strength of composites

Application-driven, multi-

attribute (static-, fatigue-,

impact-strength) efficient

simulation methods

Efficient

predictive

modeling

…

Virtual Material

Characterization

…

As-manufactured properties…

Composite simulation Composite testing

Fatigue of inter- and intra-

ply

Strain-rate dependent

behavior of composites

Micro- and meso-scale unit

cell modeling

Homogenization techniques

Effect of defects in

composites

Modeling and testing of 3D

woven

Behavior of foams an link to

helmet CAE challenge

… by multi-scale modeling

Prof. Wim VAN




Understanding behaviour of materials by

Experimental characterization

Foams

Static + fatigue Effect of defects

(static)

Impact and

crushing

Intralaminar

properties

(inside the

plies)

Interlaminar

properties

(between

the plies)

UD and Woven fabric +

0//0 and off-axis

interfaces

➢ Mode I

➢ Mode II

➢ Mixed I-II

UD and Woven fabric

Static : T & C

Fatigue: TT, CT and CC

3 lay-up sequences

Voids

Delamination

(defect)

Challenges

Key points

• Full mechanical material

characterization in static, fatigue

and dynamic (Multi-attribute)

• Robust testing method

development

• Link between material

characterization and parameter

identification for simulation

• Large amount of samples (~3000)

and data processing

• Non-standard testing to be

developed

• Cover several material factors

(e.g. strain-rate, temperature)

Foams

Delamination

3D woven

fabrics

Prof. Wim VAN




• M3 Program and addressed domains in the twin M3Strength projects






• Summary

Outline

Prof. Wim VAN




Composites fatigue modelling

Intra- and inter-laminar behaviour

Challenges

Efficient and reliable

simulation of fatigue damage

phenomena

Key points

• Intraply damage – Continuum

Damage Modelling (CDM)

•Micro-cracking

•Meta-delamination

• Interply damage – Cohesive

zone model (CZM)

•Delamination onset and

propagation

Based on failure type, amplitude & max.

stress Accurate

Micro-crack initiation prediction

Stress transfer matrix Efficient mapping

of global stress to local stresses

Brittle failure Shear failure

COUPON

FEM

with

CZM

G-N curve

(DIC)FEM

(CZM)

1

Prof. Wim VAN




Continuous fiber composites

Intra/Interlaminar fatigue prediction

Added values

• Prediction of continuous fiber

composite behavior for high cycle

fatigue

• Intra/inter-laminar coupling fatigue

• Multiaxial and variable amplitude

loadings.

Key points

• Intralaminar fatigue prediction via

stiffness degradation

• Combined with interlaminar

fatigue onset/ re-onset prediction

via energy release rate

degradation

• Non-Linear calculation to predict

accurate stress and strain fields

Road condition =

Variable Amplitude loading

Multi-axial loading

Intralaminar

Interlaminar

Energy release rate degradation

Linear damage accumulation

Intralaminar

Stiffness degradation

Permanent strain

Mean stress effects

Initial damage due to first loading

cycle➢ Considering stress/strain redistribution after damage accumulation for

both intralaminar and interlaminar elements

➢ Non-Linear FE calculation for delamination onset/re-onset prediction

Interlaminar

Free edge

Buckling

Radius , Ply drop-off…

1

Prof. Wim VAN










• Summary

Outline

Prof. Wim VAN




Composites quasi-static and dynamic

Multi-scale modelling

Challenges

•Sequential multiscale:

micro meso macro

•Virtual tests reduce

experimental ones

Key points

• Dedicated models for each scale.

• Non-linear and damage response.

• Static, fatigue or impact loads.

• Simulation tools for:

• composite design

• mechanical improvement

• cost reduction.

Microscale Mesoscale Macroscale

[0/90]4

2

Prof. Wim VAN




Virtual Material Characterization (VMC)

by multi-scale modelling

Added values•Multi-scale simulation replacing

experimental testing

•Support of different composites and

different scales

•Efficient generation of mechanical

material data

Key points•CAD interface to geometry modeler

WiseTex (KULeuven MTM)

• Fast homogenization method by

TexComp (KULeuven MTM) for

stiffness predictions

•Advanced FE-based homogenization

by ORAS (UGent MMS)

Models Material data

Homogenization

Micro scale (yarn level)

Meso scale (textile/ UD level)

VMC ToolKit

2

Prof. Wim VAN




3D Woven performance

by multi-scale modeling

Added values

•Simulation-based

optimization of 3D-woven

structures

Key points

Virtual testing

Woven fabrics

Resin selection

• Viscosity, rheology

• Wettability, permeability

• Mechanical properties

→Synolite 8388-P-1

Flatwise and edgewise

compression (square)

Material selection

New set up to open up the

fabric during impregnation

• Innovative weaving

capabilities to meet multi-

attribute requirements at

minimal weight

•Extensive experimental

program on coupons and

for optimal resin selection

•Feasibility check of multi-

scale simulation

Composite production Mechanical testing

• Honeycomb structures

• Square structures

2

Prof. Wim VAN










• Summary

Outline

Prof. Wim VAN




Effect of defects by multi-scale modelling

Challenges

Predicting the effect of voids

on statistically-controlled

damage in fiber-reinforced

composites confronts the scale

issue

Key points

• Developing a combined micro-

meso approach for simulation of

transverse cracking in the

presence of voids

• In-situ monitoring of mechanical

tests at the meso- and micro-scale

to obtain crack density evolution 0

16

32

48

64

0 0.003 0.006 0.009

σxx

(M

Pa)

εxx

reference model

model with void

Transverse cracks detected by digital image

correlation in loading micrographs

Micro-scale finite element modeling of

transverse damage

3

Prof. Wim VAN




Modeling evolution

of transverse

cracking linked to

CDM models in

Siemens software

Composites as-manufactured properties

Effect of intra- and inter-laminar defects

Added values

Simulation-based assessment

of effect of defects allowing

analysis of properties

degradation

Key pointsIntra-laminar defects:

• Developing a combined micro-

meso approach for simulation of

transverse cracking in the

presence of voids

Inter-laminar defects:

• 4P bending on omega-stiffener

sections with initial delam.

experiments vs. simulations

•Modeling the same

geometry and lay-up as

in the real specimen in

Siemens software

•Cohesive zone between

flange and skin

homogenized

Micro-level modeling of effect of

voids on transverse failure

3

Prof. Wim VAN










• Summary

Outline

Prof. Wim VAN




Composites dynamic modelling for

Impact and crushing

Challenges

1: Interpretation of dynamic test

results

2: Capturing all relevant

aspects in computationally

feasible numerical models

Key points

•Strain-rate dependency of

mechanical properties

•Many different damage types:

→ Fibre- and matrix cracking

→ Delamination of the plies

→ µ-scale debonding & yielding

→ Failure patterns in crushingFor delamination

For intra-

laminar fracture

Various failure patterns in different specimens under crush loading

Impact

Crushing

Modelling side-impact on 24-ply quasi-isotropic carbon/epoxy Dynamic tension results of

woven ±45 glass/polyamide-6

Load cell ringing at high speed.

How to interpret?

4

Prof. Wim VAN




Validated EPS foam model for impact

Challenges

Accurate model dynamic

model of EPS foam

Key points

•Cover strain-rate (loading

speed) dependence

•Cover temperature

dependence

•Cover various densities

76.7 J

115.1 J

143.9 JFoam density = 80 g/l,

room temperature (≈

18°C)

4

Prof. Wim VAN




Impact simulation of helmets

Added values

Using simulation model with

advanced foam model to

decrease helmet

development time

Key points

•Cover standard EN1078

•Cover new standard NTA 8776

(for electric bikes)

-10000

-8000

-6000

-4000

-2000

0

2000

4000

-0.01 0.01 0.03 0.05

Ro

t A

ccel

erat

ion

( r/

s2)

Time (sec)

Rot Acceleration

Rot Acc - Xaxis

Simulationwithoutcrack

4

Prof. Wim VAN










• Summary

Outline

Prof. Wim VAN




Fatigue simulation of composites

Virtual Material Characterization (VMC)

…of 3D Woven structures

Effect of defects

Impact simulation (helmets)

Key industrial outcome of the joint R&D

Beneficiaries

1

2

Technology

3

4

by multi-scale modelling

Prof. Wim VAN




• SIM and VLAIO offers an effective collaboration setup to address real industrial

challenges

• In todays product engineering, many aspects (e.g. defects) are still accounted for

by extensive testing and safety factors

• The lightweight advantage of complex materials can be better exploited with the

predictive & validated simulation tools developed in M3

• Help industry to shift away from the test-intensive lightweight engineering

Summary

Prof. Wim VAN




Acknowledgements

This work has been funded by the SBO/IBO project

“M3Strength”, which fits in the MacroModelMat (M3)

research program, coordinated by Siemens (Siemens

PLM Software, Belgium),

funded by

SIM (Strategic Initiative Materials in Flanders) and

VLAIO (Flemish government agency Flanders Innovation

& Entrepreneurship).

Thanks to:

m3 program accelerating the engineering process: from ......06 june 2017 23/# dept. of materials ,...

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