EMBEDDED ELEMENT METHOD IN MESO-FINITE ELEMENT MODELING OF TEXTILE COMPOSITES. Authors:

Transcription

1 EMBEDDED ELEMENT METHOD IN MESO-FINITE ELEMENT MODELING OF TEXTILE COMPOSITES Authors: Seyyed Ahmad Tabatabaei, Prof. Stepan V. Lomov, Prof. Ignace Verpoest

2 Overview Meso-FE modelling : importance, road maps(geometry, solid model and meshing procedure,..) Meso-FE modelling (unit cell) modelling techniques Evaluation of the embedded element method(eem); 5-H Satin composite Conclusion 2

3 Meso-FE Modeling of textile composites(1): Importance The key step in multi-scale modeling of composites is meso-level. Simplifications and less accurate models in analytical methods Needs for accurate geometries Development of Advance Numerical Codes: FEM ;Powerful Tool Different FEM in textile composites: S version (Fish), Zako et.al : M-cube method(zako et. al) ; micro, meso, and macro (M- cubic), Domain superposition technique (DST)(Jiang). Current paper: Embedded element method based on superposition technique 3

4 Meso-FE Modeling of textile composites(2): Road maps Road map for meso-fe; a:linear, b:non-linear Road maps for meso-fe a:linear b: Damage (Meso-FE modelling of textile composites: Road map, data flow and algorithms, Compos Sci Technol 2007; Lomov SV, Ivanov DS, Verpoest I, et al. 4

5 Meso-FE Modeling of textile composites(3): Geometry and solid modelling Geometry modelling WiseTex Meso-FEM of textile composites WiseTex model is imported to Abqsus( Python script of D. Ivanov) Damage modelling of the textile composites Applying contact algorithm Meshing the parts Validation of the results 5 Virtual textile composites software WiseTex: Integration with micro-mechanical, permeability and structural analysis ;Ignaas Verpoest, Stepan V. Lomov( Composite science and technology(2005))

6 Meso-FEM of textile composites(4): Meshing Geometry of the reinforcement(wisetex) Meshing(Mesh Tex) Applying BC, Load, Displacement Ansys Abaqus Meshing the imported parts from WiseTex to Abaqus 6

7 Meso-FE (UC) modelling techniques(1)(textile composites) Example: Unit cell of a woven composite Q: 1.Partitioning method?: Answer: NO; Complex geometry Warp Weft Matrix 2.Cut+ Merge( full method)? YES!; But. + 7

8 Meso-FE (UC)modelling techniques (2) Problems in the textile composites) Challenges: 1.Meshing of the matrix + Improper Surfaces 2.Missing the material orientation in full method 8

9 Meso-FE (UC) modelling techniques(3)(problems in the textile composites) Challenges: 3.Interpenetration of reinforced parts A rough solution for interpenetration problem: Cutting(removing) the penetrated regions Weft Warp Penetration in Z direction nearly = 10 microns Volume loss: 0.4% (mm^3) Problem: In damage analysis Warp yarn-front view 9 Warp yarn-back view

10 Meso-FE(UC) modelling techniques (4) Is there another method for creating a proper unit Cell? 3: Embedded element method(eem) Applicable : Any geometry, even 3D complex models Firstly used in Meso-FEM of composites using the Abaqus 10

11 Meso-FE(UC) modelling techniques (5): Embedded element method(eem) exterior tolerance for embedded elements Beam element U(reinforcement part)=f(u(host part)) U:Translational degrees of freedom(dof) Host part: Matrix Matrix Yarn 11

12 Evaluation of the EEM (1): 5-H Satin composite (unit cell) WiseTex Model Unit cell properties 12 Local strain in a 5-harness satin weave composite under static tension;part2: Meso-FE analysis, Composite science and technology(2001): Dagummati et.al

13 Evaluation of the EEM (2): 5-H Satin composite( unit cells (full and EE methods) 13 Local strain in a 5-harness satin weave composite under static tension;part2: Meso-FE analysis, Composite science and technology(2001)

14 Evaluation of the EEM (3): 5-H Satin composite(homogenized properties: F, EE ) Local strain in a 5-harness satin weave composite under static tension;part2: Meso-FE analysis, Composite science and technology(2001) 14

15 Evaluation of the EEM (4): 5-H Satin composite(stress fields) DBC-Warp 15 DBC-Warp yarns(s11) Nodal-stress profile DBC-Warp yarns(s22)

16 Evaluation of the EEM (5): 5-H Satin composite(stress fields) DBC-Weft yarns 16 DBC-Weft yarns(s11) DBC-Weft yarns(s22)

17 Conclusion EE can be used in meso-fem of textile composites. Reasonable results for homogenized properties from EEM. Reasonable prediction of stress/strain filed (maximum and minimum stress regions in meso-fem of textile composites). Limitation for using in thermal-mechanical modelling; because of different applied constraints (elements); embedded element equation, temperature, and boundary conditions. EEM should be assessed for damage analysis. 17

18 18 Thank you for your attention