Textile Preforms for Composites 1. Introduction 2. Fibres and yarns - PDF document

Textile Preforms for Composites 1. Introduction 2. Fibres and yarns 3. Textiles in general 4. Fabrics : NCF – Woven – Braided – Knitted – 3D – Spaced 5. Modelling of textile composites Stepan V. Lomov Department MTM – KU Leuven S.V. Lomov - Textile Preforms for Composites - 5. Modelling 1 1 Contents 1. Introduction 2. Geometrical models of textile reinforcement internal architecture 3. Models of textile reinforcement deformability 4. Models of textile reinforcement permeability 5. Mechanical properties of textile composites, damage 6. Conclusion: Models integration S.V. Lomov - Textile Preforms for Composites - 5. Modelling 2 1

1. Introduction 2. Geometrical models of textile reinforcement internal architecture 3. Models of textile reinforcement deformability 4. Models of textile reinforcement permeability 5. Mechanical properties of textile composites, damage 6. Conclusion: Models integration S.V. Lomov - Textile Preforms for Composites - 5. Modelling 3 Textile composites: meso-scale as a bridge to Macro z Internal architecture of the reinforcement A Q h z(x) d 1 x  Z p Q B d 2 Production Performance Deformation resistance and change of Perme- geometry ability Mechanical properties and damage Compr. Shear Tension Bending R=1/ K M Drapeability and formability Structural analysis Impregnation S.V. Lomov 27.07.2012 4 S.V. Lomov - Textile Preforms for Composites - 5. Modelling 4 4 2

М odels Internal architecture of the reinforcement Unit cell Deformation Permeability Mechanical resistance and properties and change of geometry damage Manufacturing Drapeability and Impregnation formability Pefomance Structural analysis S.V. Lomov - Textile Preforms for Composites - 5. Modelling 5 5 Software WiseTex Internal architecture of the reinforcement TexGen Unit cell Deformation Permeability Mechanical resistance and properties and FlowTex change of geometry damage CFD TexComp WiseTex Abaqus Abaqus ANSYS PAM-RTM Manufacturing PAM-FORM Drapeability and Impregnation LCM QuikForm formability RTM-Works CoData Abaqus Performance Structural analysis РАМ -SYSPLY Nastran Abaqus PAM-CRASH ANSYS S.V. Lomov - Textile Preforms for Composites - 5. Modelling 6 6 3

WiseTex software package: Virtual textiles and textile composites • commercialised by K.U.Leuven R&D 6 industrial licenses • integrated in SYSPLY package of ESI Group 30+ university licenses S.V. Lomov - Textile Preforms for Composites - 5. Modelling 7 7 Textile structures in WiseTex Woven Laminates Braided Knitted NCF S.V. Lomov - Textile Preforms for Composites - 5. Modelling 8 4

Smart composites AE sensor on-board computer structural health analysis super- computer decision on maintenance S.V. Lomov - Textile Preforms for Composites - 5. Modelling 9 1. Introduction 2. Geometrical models of textile reinforcement internal architecture • A model of internal geometry of (2D or 3D) woven fabric • From geometrical model to finite elements 3. Models of textile reinforcement deformability 4. Models of textile reinforcement permeability 5. Mechanical properties of textile composites, damage 6. Conclusion: Models integration S.V. Lomov - Textile Preforms for Composites - 5. Modelling 10 10 5

Road map: Geometrical model of the (deformed) unit cell Structure: weave / topology / interlacing – contacts, relative positions “CAD” Textile mechanics Geometry: Placement of the yarns inside the (deformed) unit cell – yarn paths / directions / twist – yarn volumes / cross-sections Meshing Textile mechanics FE mesh: Yarn volumes, contacts Deformations of the dry fabric: compression, tension, shear, bending FE S.V. Lomov - Textile Preforms for Composites - 5. Modelling 11 Road map: Geometrical model of the (deformed) unit cell Structure: weave / topology / interlacing – contacts, relative positions “CAD” Textile mechanics Geometry: Placement of the yarns inside the (deformed) unit cell – yarn paths / directions / twist – yarn volumes / cross-sections Textile mechanics Meshing FE mesh: Yarn volumes, contacts Deformations of the dry fabric: compression, tension, shear, bending FE S.V. Lomov - Textile Preforms for Composites - 5. Modelling 12 6

Woven fabric: Detailed road map Input Weave model Weave coding Elementary bent intervals Yarn shapes Ends/picks count Distance between the layers Yarn properties Crimp height and yarn thickness Full description of the geometry S.V. Lomov - Textile Preforms for Composites - 5. Modelling 13 Weave model: matrix coding Input Weave 1 2 3 level 0   1 0 1 2 model warp 1   Weave 1 layer 1 2 3 4 2 1 0 1   coding level 1 warp 2 Elementary   bent intervals 1 2 1 0 warp 3   layer 2 warp 4  0 1 2 1  Yarn shapes 4 level 2 Distance between layers Ends / 3 0 4 picks 1 Crimp, 4-1 yarn 1 1 thickness 2 2 2 1 2-1 4-2 3 3 Yarn Full prop. 4 0 3 description of 2-2 the geometry 1 1 4-3 2 2 4 2-3 warp zones NWa 3 3 warp yarns in a warp zone NWaZ[iWa] zones weft rows NWe weft layers L S.V. Lomov - Textile Preforms for Composites - 5. Modelling 14 7

Elementary bent intervals Input elementary bent interval: warp Weave model Weave coding Elementary bent intervals pos1 = OVER Yarn shapes iWa, iWe1 iWe2 Distance iWaInt between layers iWa pos2 = BELOW Ends / picks Crimp, yarn thickness Yarn Full description of prop. the geometry base weft yarns Elementary bent interval iWaInt of warp yarn iWa 1. Numbers of base weft yarns iWe1, iWe2 2. Position of the yarn vis-à-vis the base pos1, pos2 S.V. Lomov - Textile Preforms for Composites - 5. Modelling 15 Yarn shape in a bent interval – 1 Input      Weave  min , ; W A B P s model     e e e Weave , , A B P s e e e e coding Elementary       bent intervals min min | , W P s A B e e e   A , B P ( s ) e e e e Yarn shapes Distance between layers Ends / Problem B: Problem A: picks Crimp, find the positions of the yarn find the shape P(s) for the ends of the bent interval thickness given end positions ( crimp heights ) Yarn Full prop. description of the geometry element e S.V. Lomov - Textile Preforms for Composites - 5. Modelling 16 8

Yarn shape in a bent interval – 2 d22_We base contour h_Wa d11_Wa d21_We h_We d11_We z(x) d12_We p •        distance between base z ( x ) : z ( 0 ) h / 2 ; z ( 0 ) 0 ; z ( p ) h / 2 ; z ( p ) 0 contours: picks count     p 2 1   z •  dimensions: compression    min W B   dx   5 / 2 resistance 2   2 1 z 0 • crimp height: equilibrium of       1   1 z h x  3  2     2  2   bending forces   4 x 6 x 1 A x x 1 x , x     2   2 h p p S.V. Lomov - Textile Preforms for Composites - 5. Modelling 17 Characteristic functions of bent intervals d22_We 6 5 h_Wa d11_Wa d21_We h_We 4 d11_We A z(x) 3 d12_We 2 p F 1 0 0 0.2 0.4 0.6 0.8 1 h/p main parameter:          p 2 1   z B h       W B   dx F   h/p energy   5 / 2 2     2 p p 1 z 0      main property 2 2 W B h     transversal force Q F   B(k)   h ph p       p 2 1 z 1 h         dx F average curvature     5 / 2    p  2 p p 1 z 0 S.V. Lomov - Textile Preforms for Composites - 5. Modelling 18 9

Distance between the layers Input Weave shift of the model level 1 Weave layers level 2 coding Elementary bent intervals p We  Yarn shapes Distance weft j,l ; interval k 1 between layers Ends /  x picks Z l Crimp, We h jl yarn thickness Yarn Full description of prop. the geometry We Z l+1 h jl+1 z weft j,l+1 ; interval k 2 warp i      We We We We We We Wa max ( , , , , , , Z Z z shape shape d d d d d      l 1 l tight jl jl 1 1 jlk 2 jlk 1 j , l 1 , k 2 j , l 1 , k 1 j k 1 1 21 21 , j k   We We We We ) h P h P   j , l 1 j , l 1 , k jl jlk 2 2 S.V. Lomov - Textile Preforms for Composites - 5. Modelling 19 Compressibility of the yarns Input Weave model Q Weave coding Elementary bent intervals d 2 Yarn shapes d 1 Distance between layers Ends / picks Crimp, yarn thickness Yarn Full prop. description of the geometry ( ) d Q   1 1 d 10 d ( Q )        0 . 3 ... 0 . 5 2 ; 2 2 1 d 10 S.V. Lomov - Textile Preforms for Composites - 5. Modelling 20 10