High-Tech Plastics for Lightweight Solutions

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High-Tech Plastics for Lightweight Solutions

Julian Haspel, High Performance Materials, Global Application Development

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 Plastic / metal hybrid technology

 Composite technology

 CAE – integrative simulation for thermoplastic composites  Application fields

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Plastic / metal hybrid technology (PMH) –

the principle

High-tech plastics keep metal “in shape”

Sheet metal Support F₁ → Denting or buckling of lightweight structures

due to the thin wall

F₂ F₁ → → >> F₁ → F₂ → F₂ →

Strengthening the structure with small forces carried

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Form fit between plastics and metal

Plastic / metal hybrid technology (PMH) –

the principle

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Proven technology Module carrier Structural part 1. Generation System carrier 1997 2. Generation In-mold assembly 3. Generation Optical surfaces

The history

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 Hybrid technology with steel insert

 Durethan® _{BKV 30 H2.0} (PA 6 GF 30)

Advantages against steel

 10-50% weight reduction  10-40% cost reduction

 High function integration with reduced process steps

 Higher accuracy and quality  Higher load capacity

More than 70 applications and 50 million manufactured parts

Today – standard PMH for frontends

Ford Mondeo – 2007 Audi A5 – 2007 Audi A4 - 2007 Hyundai i30 – 2007 Hyundai Starex – 2007

Audi Q7 V12 – 2008 Audi A3 – 2008 Audi A7 – 2010 Audi A1 – 2010 Audi A8 – 2010

Mercedes Benz A – 2004 Chrysler 300C – 2004 VW Polo – 2001 Nissan Quest – 2003 BMW X3 – 2003

Audi A6 – 1998 Audi A4 – 2000 Ford Focus – 1998 Ford Fiesta – 2001 Renault Megane – 2002

Ford Galaxy – 2006 Ford S-Max – 2006 Audi TT – 2006 Hyundai Avant– 2006 Hyundai Veracruz– 2006

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Great potential for future development Pedal bracket Break pedal Roof frame Structural inserts Hybrid technology with aluminum xxFiat Ducato – mass production since 06/2006 x Mercedes C-Class – mass production since 03/2007 Audi TT (2006) Audi A6 (2004) Citroën C4 Picasso (2006)

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Expectations: weight neutral performance increase resp. ~ 30% weight reduction compared to standard PMH Current technology –

positive locking bond

New technology – adhesive bond Polymer Metal Molded button Polymer Metal Primer / glue

Current developments –

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 Highly reinforced PA or PBT compounds  Examples -  Durethan® DP BKV 60EF (60% GF) -  Pocan® T3150 XF (55% GF)  High modulus (HM)  High strength

 Low viscosity resins allow incorporation of high fiber amounts

Ideal for lightweight solutions

Product characteristics development

Flowability

Stiffness Tensile strength

LANXESS – product development for lightweight solutions

0 150 % 200 100 50 250 BKV 30 GF30 BKV 30EF GF30 BKV 30XF GF30 DP BKV 60EF GF60

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 Durethan®_{DP BKV 60 H2.0 EF} (PA 6 + GF60)

 Heat stabilized and easy flow  PMH with aluminum and GIT  Shot weight: 12 kg

 Part weight: 9 kg

Advantages

 Cost and weight reduction compared to SMC* or metal design

 Enabling high function integration

 Glued into the BIW** contributing to the stiffness of the car

 Not feasible in pure metal design

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Superior to pure metal designs

*Sheet Mold Compound **Body in White

GIT Channel

Example – Audi A8 spare wheel well: HM grades with

gas-injection-technology (GIT)

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 Plastic / metal hybrid technology

 Composite technology

 CAE – integrative simulation for thermoplastic composites  Application fields

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Frontend Audi A8

Composite sheet

 Thermoplastic (PA) matrix materials reinforced with woven fabrics

 Glass, carbon or aramid fibers (also hybrid)  Continuous fibers (fiber length = part length)

Advantages of hybrid composite parts

 Low weight (density e.g., 1.8 kg/dm³)

 High stiffness, strength and energy absorption  No corrosion, simple recycling

 No investment for additional tools

Full-plastic composite parts as alternative to plastic-metal structures

Further development – hybrid technology with

composite sheet

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IR heater

  Heating up above melting point

  Shaping during the closing of injection molding tool

  Subsequent injection molding of rib pattern   Demolding

Integration of composite sheet into the hybrid composite

part through in-mold forming

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Door impact beam (demonstrator) Steering column bracket

Tepex®_{+ Durethan}®

BMBF-Project “SpriForm” in cooperation with Tepex

®_{+ Durethan}®

Project in cooperation with

Example – in-mold formed hybrid composites

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Hybrid composite parts

  New material (composite sheets)   New process (one shot molding)   Simulation required for

- Mechanical component behavior - Processing (forming and molding)

LANXESS’ contribution

  New technology in virtual reality   Shortened development times   Reduced development costs   Parts designed to the limits

“No application without simulation”

Simulation is mandatory for the development of new

applications

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 Plastic / metal hybrid technology  Composite technology

 CAE – integrative simulation for thermoplastic composites

 Application fields

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Main mechanical characteristics

 Anisotropy  Non-linearity

 Strain rate dependency  Different tension / bending

stiffness

 Failure / breakage

 Rotation of fiber directions / non-orthogonal fiber directions  Temperature dependency  Moisture dependency

Tensile tests in different directions*

Str es s [MPa ] Strain [%] 0° 7.5° 15° 22.5° 30° 37.5° 45°

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18 * Tepex

®_{dynalite 102-RG600(x)/45%}

Tensile tests 45° at different strain rates*

Str es s [MPa ] Strain [%] M 1 1/s M 10 1/s M qs M 100 1/s S 1 1/s S 10 1/s S qs S 100 1/s

Validation of benchmark material model developed

by LANXESS

Tensile tests 0° at different strain rates*

Str es s [MPa ] Strain [%] M 1 1/s M 10 1/s M qs M 100 1/s S 1 1/s S 10 1/s S qs S 100 1/s

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Folding

 Fiber orientation known  Only simple geometries

Forming

 Fiber orientation not known  Complex geometries possible

Two composite sheet processing methods

Forming mechanisms – metal vs. composite sheet

Metal sheets

 Plastic deformation

 A_deformed > A_undeformed

 Wall thickness distribution

Composite sheets

  Shear (“Trellis” effect)

 A_deformed ≅ Aundeformed

  Fiber orientation distribution

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2

1

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Metal sheets Composite sheet

vs.

Processing of composite sheets via thermoforming

Two composite sheet processing methods

Forming mechanisms – metal vs. composite sheet

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Forming simulation Forming behavior

> 0.96 < 0.96 + 55° - 55° Change of fabric angle 0° 22.5° 45° Orientation of composite sheet

Forming / draping simulation of composite sheet –

example: mouse bath tube

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Forming simulation Fiber orientation Forming properties Mapping Ma te ri al D ev el o p m en t C o m p u te r A id ed En g in ee ri n g Mechanical properties

Integrative simulation of hybrid composite parts

Material model: Tepex®

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Orientation due to flow Result:

anisotropic layer

V

Flow Orientation Extensional perpendicular

Shear parallel Shear layer: _{ll to flow} Core: ⊥  to flow (fountain flow) V Boundary: random

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Alternative universal valid isotrop values do not exist Durethan®_{BKV 30 H2.0} 0 1500 F o rc e [N ] 2000 1000 500 2500 0.5 1.0 1.5 2.0 Displacement [mm] 0 2.5 3.0 long cross - 35ºC / dry / long 23ºC / dry / long 23ºC / ISO 1110 / long 85ºC / dry / long - 35ºC / dry / cross 23ºC / dry / cross 23ºC / ISO 1110 / cross 85ºC / dry / cross

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FE-model (rheology) FE-model (mechanic)

Fiberorientation (rheology)

Mapping

FEA: stiffness and strength of IM part

  Stiffness of fiber and matrix

  Geometry of fiber (L/D)

  Volumetric content of fiber ϕ

Anisotropic material model with failure crit.

Orientation averaging Strength of   Fiber   Matrix   Composite Micromecanical model Unidirectional composite Real composite Fiberorientation (mechanic) N on li ne ar ma te ria l Moldflow

Workflow – integrative simulation for

injection-molded parts

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Displacement [mm] F o rc e [N ] ₆₀₀ 900 100 200 0.4 0.6 0.2 1.4 1.8 2.4 1000 700 1100 500 800 400 300 1.2 2.0 1.0 2.2 0.8 1.6 0 1200 __Durethan®_{BKV 30 H2.0}   Room temperature (23ºC)

  Conditioned according ISO 1110

Simulation 0º Simulation 90º Simulation 45º Tests 0º Tests 90º Tests 45º

Elastic-plastic matrix properties –

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26 Forming simulation Fiber orientation Forming properties Material model: Tepex® Mapping Mechanical

properties properties Molding

Molding simulation Fiber orientation Mechanical properties Material model: Durethan® Pocan® Mapping

Integrative simulation of hybrid composite parts

Ma te ri al D ev el o p m en t C o m p u te r A id ed En g in ee ri n g

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Bonding strength depends on

  Preheating of composite sheet   Injection-molded parameters   Flow length   Material   … Injection-molded plates on

composite sheet* Tensile test  bonding strength

Bonding strength of injection-molded part

to composite sheet

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28 Forming simulation Fiber orientation Forming properties Mapping Mechanical

properties properties Molding

Molding simulation Fiber orientation Mechanical properties Material model: Durethan® Pocan® Mapping Interface properties

Integrative simulation of hybrid composite parts

Ma te ri al D ev el o p m en t C o m p u te r A id ed En g in ee ri n g Material model: Tepex®

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b

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Pole impact test

F o rc e [N ] Displacement [mm] a b c Measurement Simulation

Validation example 1 – pole impact test of a

door impact beam demonstrator

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Two different LANXESS rib materials

  Durethan®_{BKV 30 H2.0}

  Durethan®_{DP BKV 60 H2.0 EF}

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Part Testing setup

Projekt in Cooperation with Faurecia

Three point bending test

F o rc e [N ] Displacement [mm] Simulation

Durethan®_{BKV 60 EF} Measurement _Durethan_®_{BKV 60 EF}

Simulation Durethan®_{BKV 30}

Measurement Durethan®_{BKV 30}

Validation example 2 – three point bending

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Three point bending test F o rc e [N ] Displacement [mm] 1 0 Failure behavior

Validation example 2 – three point bending

test of the upper beam of a frontend (2/2)

Simulation

Durethan®_{BKV 60 EF} Measurement _Durethan_®_{BKV 60 EF}

Simulation Durethan®_{BKV 30}

Measurement Durethan®_{BKV 30}

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Test results of the prototype

 Static loads have been tested at room temperature  passed

 Weight saving correlates with calculations

Benefits

 Function integration

 Reduction of process steps  Equally distributed loads

 Corrosion protection superfluous  Weight saving

 Easy recycling

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Partnering for progress

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Failure in the composite sheet Part Testing setup

Project in Cooperation with ZF Friedrichshafen

a b c d F o rc e [N ] Displacement [mm] Measurement Simulation

ca. 0.97 _{(first crack)}ca. 1.02 Area of

failure >> 1

a b c d

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 Plastic / metal hybrid technology  Composite technology

 CAE – integrative simulation for thermoplastic composites

 Application fields

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Selec_tion

Steering rod

Airbag housings

Cross car beams

Frontends

Battery cell holder Battery housing carrier

Pedals / pedal brackets Brackets

Gas tank carrier

Module carrier Roof frames

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LANXESS – for innovative lightweight solutions

LANXESS offers extensive know-how in

lightweight solutions

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Self-developed top-notch simulation tools

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Contributing to innovations with new technologies

and high-performance materials

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