Topic 4. Role of thermodynamics in modeling the dynamics of complex materials under deformation

The mechanical behavior of most fluids and solids in our everyday life is neither purely viscous nor elastic, respectively. Rather, many intriguing combinations of these two extremes exist. While nonequilibrium thermodynamics can play an equally important role, differences exist in how the modeling is set up. While for complex fluids, one usually departs from a pure viscous basis that is enriched by structure-dynamics to account for elastic effects (i.e. viscous → viscoelastic), one often departs for complex solids from a purely elastic description that is enriched by structure-dynamics describing relaxation (i.e. elastic → elasto-viscoplastic). In these fields of research, the role of nonequilibrium thermodynamics consists in giving guidelines on how precisely to enrich the base-model, accounting for proper mutual coupling of all model components, for general nonisothermal and nonhomogeneous conditions, thus incorporating the coupling of thermodynamics with all transport (momentum, heat and mass) processes. Prominent examples, where the modeling has profited tremendously from thermodynamics (albeit not an exhaustive list!) are

• Rheology of polymer fluids (conformation tensor models, kinetic theories)
  • Dilute and Semi-Dilute Polymer Solutions (linear and nonlinear dumbbell models; wormlike chains; FENE, anisotropic drag etc.)
  • Entangled Linear and Branched Polymer Chains (reptation, pompon models)
  • Polymer Blends and Emulsions (Doi-Ohta)
  • Liquid-Crystalline Polymers (Doi/Leslie-Ericksen)
• Rheology of suspensions, micellar and shear-banding systems, multiphase systems, including fluid viscoplasticity, thixotropy and crystallization
• Elasticity (incl. phase-field approaches)
• Viscoplasticity in polymer solids, with induced anisotropy
• Plasticity in metals, dislocation-dynamics
• Damage mechanics, discontinuities
• Mechanics of structural glasses

The focus of this topic is on comprehensive modeling of complex materials dynamic behavior that is consistent with nonequilibrium thermodynamics. We thus welcome/envision contributions following this spirit, as exemplified with the above list.

Teachers (Summer school)

• Antony Beris   University of Delaware, U.S.A.
• Bob Svendsen   RWTH Aachen, Germany

Topic organizers

• Antony Beris   University of Delaware, U.S.A.
• Markus Hütter   Eindhoven University of Technology, The Netherlands

2024