Textile Composites. Rajesh Mishra and Jiri Militky Faculty of textile engineering Technical University of Liberec

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1 Textile Composites Rajesh Mishra and Jiri Militky Faculty of textile engineering Technical University of Liberec

2 Professional Development Programme at TU Liberec, August September 2010 Rajesh Mishra, TU Liberec, BASICS & NOVELTIES IN WEAVING Technical University of Liberec Czech Republic

3 Technical University of Liberec Professional Development Programme at TU Liberec, August September 2010 Czech Republic Rajesh Mishra, TU Liberec, BASICS & NOVELTIES IN WEAVING 12:32 02:01:2011

4 Polymer Composites Polymer Composites: by combining high performance fibres with a polymer matrix, polymer composites offer lightweight, corrosion free alternative to metals. Composites have a wide range of applications in aerospace, automotive, defence, marine, civil engineering etc.

5 Textile Composites :Motivation Textile structure as a flexible material helps to stabilise geometrical configuration during fabrication and cure Textile composites are overwhelmingly superior to other materials (e.g. metals) on a strength-to-weight or stiffness to-weight basis. Fabrics are anisotropic, give option to structural design Alignment of constituent fibres in preferred direction helps to reduce weight Several high performance fibres such as graphite, aramid, glass, carbon fibres are commercially available Glass is the cheapest material in terms of modulus/$, most versatile, most consistent

6 Textile Composites :Motivation Technological developments as regard to textile preform fabrication using tri-axial weaving, multi-axial weaving, three dimensional weaving, advanced CAD based braiding and knitting, and nonwovens offer limitless opportunities Availability of a large variety of cheap and unexplored natural fibres in Indian offers great challenge to develop variety of green composites Development of nanofibre production adds to the opportunity to develop wide range of functional nanocomposites for promising new applications in many fields such as mechanically reinforced lightweight components, healthcare applications, non-linear optics, battery cathodes and ionics, nano-wires, sensors and other systems.

7 Textile Composites :Motivation Development of textile composites systems satisfy specific cost/performance/availability/processability/machineability and maintainability of various design require requirements. Innumerable applications such as automotives, aerospace, marine applications, wind turbines, machine tools, industrial belts, load bearing support, tubular surface structures, civil constructions, electronics and sensors, health care products etc. Looking in all these scope, textile composites appear to be in their infancy

8 Composite Manufacturing Composite Reinforcement structure Matrix + Fibres, Yarns, Fabrics Polymers, ceramics, metals

9 Fibres used for composites Carbon - PAN, Pitch, Rayon Glass E glass: textile, roving, S Glass: higher performance for aerospace etc. Kevlar/ Twaron: ballistic, z-reinforcement Zylon: Ballistic Dyneema, Vectran, Spectra: ballistic composites Polyester, Nylon 66: stitching, airbags Polyester, Nylon, PP : thermoplastic prepregs Natural fibres : Green composites

10 Properties of textile reinforced composites Rule of Mixtures The value of descriptive parameter denoted by Pc n p c = i= 1 f i Pc = f 1 P 1 + f 2 P fnpn n = No of components in the composite f i = fraction of a component P i = the value of the descriptive parameter for the component

11 Modulus E c = f f E f +f m E m E c = Elastic modulus of the composite E f = Elastic modulus of the fibre E m = Elastic modulus of the matrix

12 Tensile Strength l f σ c = f f (1 ) σ f + 2l f m σ m σ f c = σ f ultimate tensile strength of composite f = Volume fraction of fibre l f = critical fibre length l = fibre length f = fibre tensile strength m = matrix volume fraction σ matrix tensile strength m =

13 Role of Textile structure In above expression, translation efficiency of fibre properties to the composite structure primarily depends on fibre volume fraction. The challenge is to design a textile structure which can provide maximum possible fibre volume fraction to make a high strength composite material.

14 Growth Drivers The main drivers for advanced composite use are : Need for light-weight transportation (aerospace, automotive) Alternative CO2 neutral energies (wind turbine) Industrialization of developing countries and urbanization The market is expected to grow at rates of 15% per year The industry has to develop new automation technologies and recycling options to enable further penetration especially into the automotive and wind turbine mass market

15 What is Advanced Compposites Super strong (By using specially designed noncrimp preform) Low cost/performance ratio ( Cost Optimisation Versatile ( Flexibity as well as stability) Functional (in case of nanocomposites) Green composites( Kenaf,sisal, jute)

16 Textile Materials for structural composites Material Modulus(gpd) Glass 433 Graphite 1495 Aramid 891 Carbon - Steel 290

17 Stress-strain behaviour-high performance fibres

18 Textile Composites classification Flexible : Textile reinforced rubber system Ex. Tires,inflatable life rafts, heavy duty conveyor belt Rigid : Fibre reinforced plastic system Ex. Interior and exterior panels,automotives,aircrafts,marine boats,piping products,furniture, housing construction,industrial cabinets and casings, containers,appliances, etc.

19 Textile Structural Composites Combination of Textile preforms with resin,metal and ceramic as matrix Mainly used as load bearing structures Ex. Basic frame work of building, bridges,vehicles etc. (substitute of wood and metal )

20 How textile structure helps in composites Fabrics carry most of the loads Stabilise geometrical configuration during fabrication and cure Wide range of fibres/yarns Fabrics are anisotropic, give option to structural design

21 WHY MULTIAXIAL? The fabric quality requirements for composite applications are dimensional stability, conformability and mold ability. To withstand multi-directional mechanical and thermal stresses. Require interlaminar strength and damage tolerance. Restricts the use of simple woven fabrics in the field of space engineering, automotive engineering and sports goods.

22 Properties of Multiaxial fabric (1) Dimension stable in any direction. (2) Isotropic distribution of stress forces, uniform strain behaviour.

23 TRI AXIAL WOVEN FABRIC OS and OZ warp thread W is weft thread H is width S is height

24 Braiding Applications in Composites No Limits in Braiding: Maritime Medicine Aviation Sports Aerospace Automotive etc.

25 3-D Construction

26 Why 3D Reinforced composites

27 Applications(Most Demanding Area) Aerospace Wind Energy Automotive parts Pressure vessels Civil Engineering Offshore Oil Marine

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31 State of the art.. Strips of prepreg wrapped in preferred orientations consolidated in an autoclave Advantages: Clean room process, highly repeatable fibre lay-up, FAA approved Disadvantages: Poor inter-laminar strength, poor damage tolerance, expensive, slow production speeds. Embedded sensors/actuators may cause delamination.

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33 Resin Infusion Courtesy: Gurit.com Dry fabrics draped and tacked on the mould surface Vacuum assisted Resin infusion Cheaper materials, manufacturing costs Faster production Improved damage tolerance

34 carbon fibres milled chopped spooled felted dry towpreg UD prepreg pultrusion textile preforms broad cloth draping preform assembly narrow RTM, VARTM, RFI 3D profiles thermoplastic textile prepregs hot stamping welding wet winding textile prepregs oven curing filament winding tape robotic tow/tape layup Autoclave / Quickstep Laser cutting Laser guided ply lay-up

35 Textiles for Reinforcement: flexible composites Inflatable systems: automotive airbags, inflatable aircraft hangers Autoliv plc

36 Inflatable space systems ILC Dover

37 Airships, statics, cargo lifters ILC Dover

38 Inflatable hangers ITEK-USA

39 Textile Preforming This is the labour-intensive part of high-tech industry Weaving Braiding Stitching, tufting, embroidery Robotic tow placement, tape laying Near-net preforming for thick fittings Winding/wrapping

40 Textile Composites 2D broadcloth: woven prepregs for surface plies for improved machinability and damage tolerance Dry fabrics for draping on complex mould surfaces for resin infusion Interlaced Woven & braided structures Stitched- NCF

41 Stepping lap-joint: 2.5D broad cloth Resin Rich area Butt Joint Resin Rich area Resin Rich area Conventiona Lap Joint Fabric with Half-thickness at the Joint Stepped lap-joint Multi-step lap joint/ply drop off for 3D composites

42 3D weaving

43 3D weaving: weave styles

44 Creating slits and pockets in 3D weaves

45 3D Weaving

46 Spacer structures

47 Multiple steps in width direction

48 Multi-step lap joint (in length direction)

49 Tapering without dropping tows

50 Multi weft insertion 3D weaving: under development at Manchester

51 step 1 Braiding

52 Mandrel over-braiding

53 Examples of braidied composites: NLR Trailing Arm

54 Stitching/tufting for through thickness reinforcement

55 Delamination in stitched and unstitched sandwich panels: [3]

56 Stitching: advantages over 3D weaving in terms of flexibility on fibre orientations A380 bulkhead

57 embroidery

58 Near-net dry fibre assembly with robotics

59 4 axes Cartesian Robotic system 3m x 2m x 0.6 m

60 GE 90 Wide cord Fan Blade CFAN produces composite blades with 1000 draped UD & fabric plies Toughened Epoxy resin Thickness feet length, 20kg in weight SNECMA claims 25 to 30% cost reduction And better damage tolerance 3D woven Preform by Albany Techniweave ( )

61 Multi-axial fibre placement

62 Multi-axial Fibre placement

63 Vacuum infusion

64 Near-net shapes

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68 Fan Blade GE, Snecma, Techniweave

69 New concept fuselage winding, complex ducting, grid stiffened structures + through thickness reinforcement

70 8 axes Robotic system

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72 Conclusion Composites industry offers a high value added opportunity to the textile industry Major aerospace companies have been investing all over the world.