Viscoelasticity, logarithmic stresses, and tensorial transport equations

Fuente: arXiv
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Main Authors: Ciampa, Gennaro, Giusteri, Giulio G., Soggiu, Alessio G.
Format: Preprint
Published: 2023
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author Ciampa, Gennaro
Giusteri, Giulio G.
Soggiu, Alessio G.
author_facet Ciampa, Gennaro
Giusteri, Giulio G.
Soggiu, Alessio G.
contents We introduce models for viscoelastic materials, both solids and fluids, based on logarithmic stresses to capture the elastic contribution to the material response. The matrix logarithm allows to link the measures of strain, that naturally belong to a multiplicative group of linear transformations, to stresses, that are additive elements of a linear space of tensors. As regards the viscous stresses, we simply assume a Newtonian constitutive law, but the presence of elasticity and plastic relaxation makes the materials non-Newtonian. Our aim is to discuss the existence of weak solutions for the corresponding systems of partial differential equations in the nonlinear large-deformation regime. The main difficulties arise in the analysis of the transport equations necessary to describe the evolution of tensorial measures of strain. For the solid model, we only need to consider the equation for the left Cauchy-Green tensor, while for the fluid model we add an evolution equation for the elastically-relaxed strain. Due to the tensorial nature of the fields, available techniques cannot be applied to the analysis of such transport equations. To cope with this, we introduce the notion of charted weak solution, based on non-standard a priori estimates, that lead to a global-in-time existence of solutions for the viscoelastic models in the natural functional setting associated with the energy inequality.
format Preprint
id arxiv_https___arxiv_org_abs_2306_14049
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Viscoelasticity, logarithmic stresses, and tensorial transport equations
Ciampa, Gennaro
Giusteri, Giulio G.
Soggiu, Alessio G.
Analysis of PDEs
Mathematical Physics
Fluid Dynamics
35Q35, 35Q74, 35D99, 76A10, 74D99
We introduce models for viscoelastic materials, both solids and fluids, based on logarithmic stresses to capture the elastic contribution to the material response. The matrix logarithm allows to link the measures of strain, that naturally belong to a multiplicative group of linear transformations, to stresses, that are additive elements of a linear space of tensors. As regards the viscous stresses, we simply assume a Newtonian constitutive law, but the presence of elasticity and plastic relaxation makes the materials non-Newtonian. Our aim is to discuss the existence of weak solutions for the corresponding systems of partial differential equations in the nonlinear large-deformation regime. The main difficulties arise in the analysis of the transport equations necessary to describe the evolution of tensorial measures of strain. For the solid model, we only need to consider the equation for the left Cauchy-Green tensor, while for the fluid model we add an evolution equation for the elastically-relaxed strain. Due to the tensorial nature of the fields, available techniques cannot be applied to the analysis of such transport equations. To cope with this, we introduce the notion of charted weak solution, based on non-standard a priori estimates, that lead to a global-in-time existence of solutions for the viscoelastic models in the natural functional setting associated with the energy inequality.
title Viscoelasticity, logarithmic stresses, and tensorial transport equations
topic Analysis of PDEs
Mathematical Physics
Fluid Dynamics
35Q35, 35Q74, 35D99, 76A10, 74D99
url https://arxiv.org/abs/2306.14049