Extended constitutive laws for lamellar phases

Extended constitutive laws for lamellar phases

Blog Article

Classically, stress and strain rate in linear viscoelastic materials are related by a constitutive relationship involving the viscoelastic modulus G(t).The same constitutive law, within Linear Response Theory, relates currents of conserved quantities and gradients of existing conjugate variables, and it involves the autocorrelation functions of the currents in equilibrium.We explore the consequences of the latter relationship in the case of a mesoscale model of a block Crutches copolymer, and derive the resulting relationship between viscous friction and order parameter diffusion that would result in a lamellar phase.We also explicitly consider in our derivation the fact that the dissipative part of the stress tensor must be consistent with the uniaxial symmetry of the phase.We PRINT then obtain a relationship between the stress and order parameter autocorrelation functions that can be interpreted as an extended constitutive law, one that offers a way to determine them from microscopic experiment or numerical simulation.