Sebastian Kreissl, Thomas Senner, Arnulf Lipp, Josef Meinhardt. INDUSTRIAL FORMING SIMULATION OF MULTI-LAYERED UD NON-CRIMP-FABRICS. 13. LS-DYNA FORUM, 07.10.2014, BAMBERG.
OUTLINE. BMW i. Production Process of CFRP Shell Structures. Large Scale Production of CFRP Parts. Semi-finished Carbon Fiber Products. Challenges for the Simulation. Strategy for Modelling of Unidirectional Non-Crimp-Fabrics. Simulation Results for Prototype Part. Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 2
BMW i. ELECTROMOBILITY & LIGHTWEIGHT CONSTRUCTION. BMW i3 BMW i8. Life-Module Drive-Module Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 3
PRODUCTION PROCESS OF CFRP SHELL STRUCTURES. RESIN TRANSFER MOLDING (RTM) PROCESS. Fiber Matrix Finished Part Components Finishing Preparation Trimming Stacking Wetting Solidification Deformation Wetting & Solidification Preforming Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 4
LARGE-SCALE PRODUCTION OF CFRP PARTS. INDUSTRIAL AUTOMATION. Single Item Production. Large-Scale Production. www.boeing.com Small number of units. Highly flexible. Long cycle/process times.. Large number of units. Highly automated. Short cycle/process times. Forming simulation to avoid cost and time intensive changes in the tooling /process. Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 5
SEMI-FINISHED CARBON FIBER PRODUCTS. EXAMPLES. Fiber/Roving: 3K Roving 50K Roving Textile: Unidirectional noncrimp-fabric (UD- NCF) Carbon fiber roving. Synthetic stitch thread. Glasfiber thread. Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 6
Force CHALLENGES FOR THE SIMULATION. EXCERPT. Various Material Types. Bending Stiffness. Steel (t~0.3mm): E~2.1e5 MPa Displacement UD NCF(t~0.3mm): E ~2.1e5 MPa Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 7
STRATEGY FOR MODELING UD-NCF. MODULAR APPROACH. UD-NCF Composition of at least two structures and materials. UD fiber structure: Compact structure. Nonlinear elastic material. Simplified Modeling UD fiber model: Contin. approach (shell elements). UD fiber material model. Modularization and Characterization Representative Unit Cell Model Warp-knitted stitch structure: Net-like structure. Nonlinear elastic material with failure. Warp-knitted stitch model: Discrete approach (beam elements). Cable material model Resulting macroscopic material behavior by superimposing both models. Coincident nodes. Senner et al.: A modular modeling approach for describing the in-plane forming behavior of unidirectional non-crimp-fabrics, Production Engineering Research and Development, DOI 10.1007/s11740-014-0561-z, pp 1-9 Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 8
Normalized Force [ ] STRATEGY FOR MODELING UD-NCF. MODULAR APPROACH. Calibration: Stitching: tensile test of stitch thread. UD-NCF: tensile test ( to fibers). 1.2 1.0 0.8 0.6 Validation: Picture-Frame Test. Mat.#1: Warp dir. (Exp.) Mat.#1: Warp dir. (Sim.) Mat.#1: Weft dir. (Exp.) Mat.#1: Weft dir. (Sim.) Mat.#2: Warp dir. (Exp.) Mat.#2: Warp dir. (Sim.) Mat.#2: Weft dir. (Exp.) Mat.#2: Weft dir. (Sim.) www.zwick.de 0.4 0.2 0.0 0 5 10 15 20 25 30 Shear Angle ɤ [ ] Senner et al.: A modular modeling approach for describing the in-plane forming behavior of unidirectional non-crimp-fabrics, Production Engineering Research and Development, DOI 10.1007/s11740-014-0561-z, pp 1-9 Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 9
STRATEGY FOR MODELING UD-NCF. BENDING STIFFNESS. Steel (t~0.3mm): E~2.1e5 MPa UD NCF (t~0.3mm): E~2.1e5 MPa Discontinuity: low bending stiffness due to sliding of fibers. www.xcracer.com Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 10
STRATEGY FOR MODELING UD-NCF. BENDING STIFFNESS. Edge with load cell Axis of rotation Specimen Clamping T. Senner et al.: Bending of unidirectional non-crimp-fabrics: experimental characterization, constitutive modeling and application in finite element simulation, Production Engineering Research and Development, DOI 10.1007/s11740-014-0568-5, pp 1-10. Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 11
STRATEGY FOR MODELING UD-NCF. BENDING STIFFNESS. Continuous material (Polypropylene) UD-NCF T. Senner et al.: Bending of unidirectional non-crimp-fabrics: experimental characterization, constitutive modeling and application in finite element simulation, Production Engineering Research and Development, DOI 10.1007/s11740-014-0568-5, pp 1-10. Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 12
STRATEGY FOR MODELING UD-NCF. BENDING STIFFNESS. Beam theory (Timoshenko): dw x 2 dx M x qx E I G A G k G UD-NCF T. Senner et al.: Bending of unidirectional non-crimp-fabrics: experimental characterization, constitutive modeling and application in finite element simulation, Production Engineering Research and Development, DOI 10.1007/s11740-014-0568-5, pp 1-10. Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 13
STRATEGY FOR MODELING UD-NCF. BENDING STIFFNESS. Beam theory (Timoshenko): dw x 2 dx M x qx E I G A G k G UD-NCF T. Senner et al.: Bending of unidirectional non-crimp-fabrics: experimental characterization, constitutive modeling and application in finite element simulation, Production Engineering Research and Development, DOI 10.1007/s11740-014-0568-5, pp 1-10. Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 14
STRATEGY FOR MODELING UD-NCF. BENDING STIFFNESS. Calibration. T. Senner et al.: Bending of unidirectional non-crimp-fabrics: experimental characterization, constitutive modeling and application in finite element simulation, Production Engineering Research and Development, DOI 10.1007/s11740-014-0568-5, pp 1-10. Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 15
STRATEGY FOR MODELING UD-NCF. BENDING STIFFNESS. Experiment Simulation Fiber direction Fiber direction T. Senner et al.: Bending of unidirectional non-crimp-fabrics: experimental characterization, constitutive modeling and application in finite element simulation, Production Engineering Research and Development, DOI 10.1007/s11740-014-0568-5, pp 1-10. Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 16
SIMULATION RESULTS FOR PROTOTYPE PART. PLIES 1-7. Forming operation (after gravity load case). Ply 7 Ply 6 Ply 5 Ply 4 Ply 3 Ply 2 Ply 1 Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 17
SIMULATION RESULTS FOR PROTOTYPE PART. PLIES 1-7. Forming operation (after gravity load case). Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 18
SIMULATION RESULTS FOR PROTOTYPE PART. DETAIL: -45 PLY. Projected Compression of fiber ( ) -0.01-0.02-0.03-0.04-0.05-0.06-0.07-0.08-0.09-0.10 Waviness/fold. Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 19
LITERATURE. T. Senner, S. Kreissl, M. Merklein, M. Meinhardt, A. Lipp (2014): A modular modeling approach fordescribing the in-plane forming behavior of unidirectional non-crimp-fabrics, Production Engineering Research and Development, DOI 10.1007/s11740-014-0561-z, pp 1-9. T. Senner, S. Kreissl, M. Merklein, M. Meinhardt, A. Lipp (2014): Bending of unidirectional non-crimp-fabrics: experimental characterization, constitutive modeling and application in finite element simulation, Production Engineering Research and Development, DOI 10.1007/s11740-014-0568-5, pp 1-10. Forming Simulation of UD-NCF, BMW Group, 07.10.2014 Page 20
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