Composites Composite Production Methods. Remko Akkerman Laurent Warnet C O M PO SI T ES GRO U P U N I V ERSI T Y O F T W EN T E

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1 C O M PO SI T ES GRO U P Composites Composite Production Methods U N I V ERSI T Y O F T W EN T E Remko Akkerman Laurent Warnet

2 fibre glass carbon... resin impregnation thermoplastic thermoset CFRP continuous fibre reinforced plastic MEASURE heater pump isolation water cooling thermally induced distortions of single curvature composites 45 o damage development in cross-ply beams MEASURE prepreg production distortion measurement autoclave RTM hot pressing rubber moulding... low density high stiffness high strength residual stresses product distortions lightweight part usually thin walled good corrosion resistance assembly MODEL spring forward lightweight structure geometry based model for the thermomechanical properties of woven fabric reinforced composites CONTROL optimise process by inverse analysis micromechanical stress analysis inservice loading impact and compression after impact of curved panels MODEL mechanically induced stresses crack initiation & crack growth structural deformation and failure delamination growth during compression after impact CONTROL optimal properties of constituents & interface damage resistant & damage tolerant designs optimise for impact energy absorption

3 Composite fabrication techniques: That s about Impregnating the fibres Wetting

4 Composite fabrication techniques: Impregnating a porous medium Needs: Low viscosity resin Uncured Thermoset Thermoplast above T m + pressure

5 Direct methods: Direct impregnation Fibre Yarn / Fabric Layer after layer Liquid resin Resin Thermosetting Product Product ready for finish

6 Direct method: Hand lay-up Cold cure thermoset (Polyester) High labour costs Low tooling costs Low performance Emission Small series Prototyping large parts Low control!

7 Direct method: Filament winding Thermoset High labour costs Low tooling costs Medium performance Low-Medium series Large parts Oven for curing

8 Direct method: Filament winding: Resin bath Other geometries

9 Direct method: Pultrusion / Pull-winding / Pull-braiding Thermoset Continuous process! Medium tooling costs Medium-high performance Medium-Large series Small-medium cross-sections

10 Direct method: Pultrusion / Pull-winding / Pull-braiding Similar as Pultrusion but tailor-made lay-up!!

11 Semi-Direct methods: Direct impregnation of a dry preform Fibre Yarn / Fabric Preform On basis of dry preform Resin Product Liquid resin Thermoset Product ready for finish

12 Semi-direct method: Liquid Composite Moulding (LCM) Preform in a mould is filled with resin Several variants: Resin Transfer Moulding (RTM) Resin Infusionn under Flexible Tooling (RIFT)

13 Semi-direct method: Resin Transfer Moulding (RTM) Preform is filled under pressure Preform in mould Resin injection Resin cure Part removal Medium labour costs High tooling costs High performance Medium series Small medium size

14 Semi-direct method: Resin Transfer Moulding (RTM) Fibre content determined by cavity size Mould costs high (Pressure, control )

15 Resin Transfer Moulding (RTM)

16 Semi-direct method: Resin Infusion under Flexible Tooling (RIFT) Preform is filled under Vacuum Vacuum outlet Bagging film Resin inlet Sealant tape Medium-high labour costs Low tooling costs Medium performance Medium series Medium Large size

17 Semi-direct method: Resin Infusion under Flexible Tooling (RIFT) Fibre content determined by pressure Mould costs low (low pressure )

18 Semi-direct method: Liquid Composite Moulding (LCM) Impregnation: A long way to go!

19 Semi-direct method: Liquid Composite Moulding (LCM) Material properties to control filling: Viscosity Permeability= =f(fibre structure / orientation / concentration) Darcy s law: Q = K δp µδx (Macro)

20 Meso flow dominated Semi-direct method: Liquid Composite Moulding (LCM) Flow on a mesoscale: Micro flow dominated

21 Semi-direct method: Liquid Composite Moulding (LCM) Flow on a meso-scale: Void formation

22 Semi-direct method: Liquid Composite Moulding (LCM) Common characteristics: Function integration:

23 Multi-step methods: Composite processing based on prepreg Fibre Yarn / Fabric Prepreg + Resin On basis of preimpregnated layer Product Semi-Product Product Variants for thermosets and thermoplastics

24 Multi-step methods: Autoclave curing Mainly thermosetting matrix High labour costs High tooling costs High performance Long cycle time Small-large products Function integration

25 Multi-step methods: Autoclave curing Constraints on prepreg: Flexibility Drapability Tack Thermoset Simple geometries possible with thermoplastics

26 Multi-step methods: Autoclave curing Vacuum: Compressing the layers (Debulking) Withdrawing volatiles

27 Multi-step methods: Rubber pressing Needs semi-product Thermoplastic matrix Low-medium labour costs High tooling costs High performance Short cycle time Small-medium products

28 Multi-step methods: Tape placement Tailor-made Thermoplastic Thermoset (+autoclave) Low labour costs Medium-high tooling costs High performance Medium cycle time Medium Large products

29 Interaction Fabrication method -design Deformation due to forming: Fibre reorientation S S S S S S S S S S S S

30 Interaction Fabrication method -design Deformation due to forming : Fibre / Matrix concentration Corner behaviour = f (fabrication technique) ex: RTM or Rubber pressing, Autoclave

31 Choice of a fabrication techniques: Parameters playing a role: Amounts of products, cycle time, costs Material (Matrix) Performance V f Fibre distribution Void content Control of the process Reproducibility Shape complexity Assembly

32 Direct methods: Hand lay-up Productivity 5 Series size Function integration Part size / cost Complex geometry Technical Simplicity Performance

33 Direct methods: Filament Hand Winding lay-up Productivity 5 Series size Function integration Part size / cost Complex geometry Technical Simplicity Performance

34 Direct methods: Pull-Processes Hand lay-up Productivity 5 Series size 4 3 Part size / cost 2 1 Continuous Process Thermoset Tailor-made lay-up Function integration 0 Complex geometry Technical Simplicity Performance

35 Semi-direct methods: Resin Transfer Hand lay-up Moulding Productivity 5 Only for Thermosets Series size Function integration Part size / cost Complex geometry Technical Simplicity Performance

36 Semi-direct methods: Resin Infusion Hand Flexible lay-up Tooling Productivity 5 Vacuum outlet Bagging film Resin inlet Series size Sealant tape Part size / cost 1 0 Only for Thermosets Function integration Complex geometry Technical Simplicity Performance

37 Multi-step methods: Hand lay-up Autoclave Productivity 5 Only for Thermosets Series size Function integration Part size / cost Complex geometry Technical Simplicity Performance

38 Multi-step methods: Rubber Hand Pressing lay-up Productivity 5 Only for Thermosets Series size Function integration Part size / cost Complex geometry Technical Simplicity Performance

39 Multi-step methods: Hand lay-up Tape layer Productivity 5 Only for Thermosets Series size Function integration Part size / cost Complex geometry Technical Simplicity Performance