Multiphysics design of materials

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Materials need to meet structural, thermal, and electromagnetic and transport property requirements simultaneously for various new applications. This presentation provides an overview of multiphysics design of materials with special reference to composites using micromechanics. The unitcell modeling and property prediction methodology are detailed. The elastic modulus, thermal conductivity, diffusion coefficient prediction method and results are reported. A two stage sequentially coupled method is also outlined for accelerated application and material development for metamaterials. Composite processing related micromechanical models to predict permeability is also reported. The material properties related to product and process design aspect of fiber reinforced and cellular composites are highlighted.

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Multiphysics design of materials

  1. 1. Multiphysics Design of Materials Dr Raj C Thiagarajan ATOA Scientific Technologies Materials need to meet structural, thermal, and electromagnetic and transport property requirements simultaneously for various new applications. This presentation provides an overview of multiphysics design of materials with special reference to composites using micromechanics. The unitcell modeling and property prediction methodology are detailed. The elastic modulus, thermal conductivity, diffusion coefficient prediction method and results are reported. A two stage sequentially coupled method is also outlined for accelerated application and material development for metamaterials. Composite processing related micromechanical models to predict permeability is also reported. The material properties related to product and process design aspect of fiber reinforced and cellular composites are highlighted. ATOA Scientific Technologies Engineering Simulation For Innovation
  2. 2. Composite?Composite Materials provide us the unique opportunity toengineering material with required Designer properties.Combination of two or more constituents to perform betterthan individual constituents.Macroscopically homogeneous and microscopically inhomogeneous.Homogeneous at n length scale and heterogeneous at (n-1) length scale.Nature Designer Materials… References: Balsa wood : Gibson, L.J. and Ashby, M.F., 1999. Cellular Solids: Structure and Properties, Cambridge University Press, 1999. Toucan beak: Seki Y. et.al.,Structure and mechanical behavior of a toucan beak, Acta Materialia, 53 ,5281–5296, 2005. http://www.theallineed.com/engineering/06012421.htm ATOA Scientific Technologies Engineering Simulation For Innovation
  3. 3. Multiphysics Design of Materials Elastic Structural constants Super structural Thermal Thermal conductivity Superinsulation permeability ElectromagneticCAD Model and permittivity Metamaterials Sound Acoustic Acoustic transmission loss bandgaps Diffusion Transport Permeability Super flow Current Future Designer properties Extremel Properties ATOA Scientific Technologies Engineering Simulation For Innovation
  4. 4. The Physics Physics Governing Eqs* Constitute Eqs* Comments Static:, Navier’s equation, Hooke’s law Structural for stress strain relation. F, volume forces, σ,stress tensor, ε, strain tensor, D, stiffness matrix Heat Equation, Fourier’s law: ρ,density. Thermal Cp, heat capacity, k, thermal conductivity, Q,heat source. Helmholtz eq: ω, angular freq, ρ0, fluidCAD Model density, cs, speed of sound, q, source, Acoustic Dtl, transmission-loss coefficient, Wi, incident and Wt is the transmitted sound power. Diffusion N ave Fick’s law, Diffusion Coeff. c is the Deff = concentration, D is the diffusion coefficient, and R is a reaction rate ∆c v η ∆x Darcy’s law, Permeability, : v, velocity, µ, Porous flow K= ∆P dynamic viscosity, K, permeability and P, Pressure. * Equations from COMSOL documentation ATOA Scientific Technologies Engineering Simulation For Innovation
  5. 5. Engineering of material properties 1 Nano >1X property • Virtual Product and 0.8 process design Normalized Property (e.g. Nano • Paradigm shift in 0.6 Micro = 1X property • predicting properties Micro 0.4 @ 50 of weight • to Modulus) Macro <1X property • engineering properties. 0.2 Macro 0 0 0.2 0.4 0.6 0.8 1 Normalized Density / Vf Engineered for Super and Unusual properties ATOA Scientific Technologies Engineering Simulation For Innovation
  6. 6. Computer Aided Micromechanics (CAMM)• Study of composite behavior from constituents• Aims at finding a volume elements /unit cell Typical Micro structure/ morphology of composites response to prescribed Homogenization and mechanical loads. Fibre Unit cell are key CAMM property prediction Localization and Homogenization relationship Statically equivalent / Where, Periodic Ω−volume, Γ-surface, u(x)– deformation vector representation of t(x)– surface traction vector nΓ – surface normal vector morphology Homogenized / Periodic Boundary Conditions Typical Unit cell Model ATOA Scientific Technologies Engineering Simulation For Innovation
  7. 7. Structural• Advanced structural composites are known for their specific strength and stiffness properties.• Constituent properties,• Periodic BC Schematics of stress-• Global loads, strain behavior• local stress and strain.• Anisotropic Stiffness and failure properties are critical for application performance prediction Typical Results ATOA Scientific Technologies Engineering Simulation For Innovation
  8. 8. Thermal: k• Low k: Insulation: Energy saving,• High k: Conductor: Thermal management• Thermal conductivity measurement method was implemented for k prediction.• Convection and radiation components of air with equivalent conductivity for overall performance. ATOA Scientific Technologies Engineering Simulation For Innovation
  9. 9. Transport : Diffusivity Porous medium CompositesApplication: Waterdesalination,filtration.Fick’s law D1 1 m2/s D1 1 m2/s D2 5 m2/s C0 100 mol/m3 C0 100 mol/m3 k 5 m/s k 5 m/sEffective diffusivity vf dx 0.5 1m vf dx 0.5 1 mprediction for porous Deff 0.32 m2/sec Deff 2.002101 m2/sand compositemedium ATOA Scientific Technologies Engineering Simulation For Innovation
  10. 10. Acoustics: PM L Structural + acoustics coupling Ex cit a t io n o f P la n e W a v eVirtual Fluid domain A irAcoustics Flu id St r u ct u r eTests I n t e r a ct io n Flu id St r u ct u r e In t e r a ct io n A ir Solid – Fluid Interface Pe r io d ic P e r io d ic Bo u n d a r y Co n d it io n sSound Bo u n d a r y Co n d it io n s Load on solid domain PM LInsulationpanels (STL) Acceleration – Fluid domainAcousticBandgaps MRecent Developments Γ X Eig. Frequency = 5.07e14 Hz ATOA Scientific Technologies Engineering Simulation For Innovation
  11. 11. Electromagnetics: Unusualproperties• Two stage sequentially coupled process for accelerated development by numerical experiments.• Macro simulation to Macro: Performance Micro: Material prediction Design explore the Novel application design with •Negative refractive •Dielectric effective properties. index constant •Super lens Focusing •Permeability• Micro simulations to •Cloaking •Elastic design the materials for properties the required effective properties. Computational micromechanics for accelerated application development. ATOA Scientific Technologies Engineering Simulation For Innovation
  12. 12. Flow: Permeability: Composite processing Input Process parameters injection port location/nos • RTM, VARTM vacuum port location/ nos Temperature, Pressure • Impregnation is critical to quality and performance Gravity forces • Macro flow through preform/ strands and micro Material Reinforcement flow through individual fibers. Lay-up sequence No of layers • Predict permeability from reinforcement morphology Fibre architecture Resin Viscosity Darcy’s law Flow chart K ∆P illustrating u=− ⋅ µ ∆x VARTM v process P1 simulation P0 dx k Output Prediction Pressure Volume fraction Flow path Thickness Permeability Flow time Porosity Weight Design of Material for Product and Process Design ATOA Scientific Technologies Engineering Simulation For Innovation
  13. 13. Multiphysics Design of materials• Virtual material property prediction• Engineering of constituents for superior properties• Virtual experimental characterization of material properties• Product and process performance prediction Acknowledgement and References: Multiphysics Design of composites, Keynote talk, The COMSOL Conference 2009 Bangalore,. November 13-14, 2009. ATOA Scientific Technologies Engineering Simulation For Innovation 13
  14. 14. Contact ATOA Scientific Technologies for MULTIPHYSICS ENGINEERING SIMULATIONSStructural ↔ Thermal ↔ Flow ↔ Dynamics ↔ Acoustics ↔ Optics ATOA Scientific Technologies is an engineering 14 simulation service provider, with a specialty onMultiphysics, Multiscale and Multimaterials, forinnovative product and process development to cut cost and cycle time for our clients. ATOA Scientific Technologies www.atoastech.com ATOAST.HQ@ATOAST.COM ATOA Scientific Technologies Engineering Simulation For Innovation

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