Local Approaches in Composites Dmitry S. Ivanov Bristol Composites - PowerPoint PPT Presentation

Local Approaches in Composites Dmitry S. Ivanov Bristol Composites Institute – National Composites Centre conference 2019 21/11/2019

2 To discuss Local tuning properties of the composite structures or composite precursors for efficiency and cost • Locality for forming • Locality for functionality • Locality for composite properties • Locality of precursor testing

3 Locality for forming Mark Turk, Adam Thompson, Jonathan Belnoue, Stephen Hallett, Dmitry Ivanov  Complex shape (taper, convex/concave corners) – drapable but not formable  Solution = patches of liquid thermally-conditioned fast-curing resin:  No interference with fibre architecture  Viscosity of the patches – can be tuned by staging to advantageous degree of cure Non-optimised patch Turk M.A., Vermes B., Thompson A.J., Belnoue J.P.-H., Hallett S.R., Ivanov D.S. Mitigating forming defects by local modification of dry preforms, Compos A 128 (2020)

4 Locality for forming Mark Turk, Adam Thompson, Jonathan Belnoue, Stephen Hallett, Dmitry Ivanov  Patch placement – complex multi-parameter optimisation -> patch properties, size, position, orientation – all play role.  Orientation of narrow “stripe patches” = allows to strike a right balance between shear rigidity and bending stiffness of modified fabric  Forming made possible without blank holders, springs, or additional arrangements Patch strips E D C A B Critical corner Turk M.A., Vermes B., Thompson A.J., Belnoue J.P.-H., Hallett S.R., Ivanov D.S. Mitigating forming defects by local modification of dry preforms, Compos A 128 (2020)

5 Locality for multi-matrix composites Mark Turk, Michael Elkington, David Anthony, Emile Greenhalgh, Dmitry Ivanov Integrating non-formable:  Functional elements  Reparable patches  Reformable edges  Toughening Segmentation of Depositing non- Optimisation through crack- Forming and non-formable parts formable elements simulation stoppers infusion

6 Locality for mechanical performance University of Machester, Imperial College London, University of Bristol  Patch placement – local tailoring of material properties through high volume fraction of additives  Local fibre steering in braiding process Stanier D., Radhakrishnan A., Gent I., Roy S.S., Hamerton I., Potluri P., Scarpa F., Shaffer M., Ivanov D.S. Matrix- graded and fibre-steered composites to tackle stress concentrations, Compos Struct 207 (2019) 72-80.

7 Locality for mechanical performance Hengli Cao, Laveena Thadhani, Ric Sun, Luiz Kawashita, Dmitry Ivanov open hole patch Braiding simulations ¼ of sample Stress analysis  Analysis of locally varying fibrous and matrix architectures  Combined numerical simulation of process and mechanical modelling of the resultant materials with embedded elements

8 Locality for mechanical performance Hengli Cao, Arjun Radhakrishnan, Dmitry Ivanov  Sample fully infused with “patch material” is not as effective as when locally introduced  Patch shape matters – optimum shape is complex  Steering damage away from the critical location can be beneficial  Patch material/configuration can change the failure mode Redesigning stress distribution around open hole Diverting damage accumulation from critical Change of failure mechanisms in locations patched samples

9 Patch deposition Arjun Radhakrishnan, Ian Hamerton, Dmitry Ivanov Patch printing = out-of vacuum bag process. Patch quality is found to be tunable. Matching consolidation parameters to resin chemorheology Consolidation analysis of patches with various degree of cure (DOC) Rheological characterisation of fast curing functionalised resins Path morphology for various processing conditions

10 Locality of testing for precursors Anatoly Koptelov, Jonathan Belnoue, Stephen Hallett, Dmitry Ivanov  The systems is set to recognise Library of models the flow/deformation modes Shear flow Percolation flow by its characteristic signatures Tow scale Fibre-scale Patch-scale No slip Zero friction Testing machine Autonomous Output: flow Process tester mode, material optimisation real-time data properties processing  Proof-of-concept in virtual space – right flow mode is recognised automatically

11 Acknowledgements  EPSRC Future Composites Manufacturing Hub CIMComp, Core Project “Manufacturing for structural applications of multifunctional composites”  EPSRC Platform Grant “SIMulation of new manufacturing PROcesses for Composite Structures” (SIMPROCS)