Calculus of Variations and Geometric Measure Theory

S. Almi - R. Badal - M. Friedrich - S. Schwarzacher

Thermo-elastodynamics of nonlinearly viscous solids

created by almi1 on 04 Sep 2024

[BibTeX]

Preprint

Inserted: 4 sep 2024
Last Updated: 4 sep 2024

Year: 2024

ArXiv: 2409.01229 PDF

Abstract:

In this paper, we study the thermo-elastodynamics of nonlinearly viscous solids in the Kelvin-Voigt rheology where both the elastic and the viscous stress tensors comply with the frame-indifference principle. The system features a force balance including inertia in the frame of nonsimple materials and a heat-transfer equation which is governed by the Fourier law in the deformed configuration. Combining a staggered minimizing movement scheme for quasi-static thermoviscoelasticity 35, 2 with a variational approach to hyperbolic PDEs developed in 5, our main result consists in establishing the existence of weak solutions in the dynamic case. This is first achieved by including an additional higher-order regularization for the dissipation. Afterwards, this regularization can be removed by passing to a weaker formulation of the heat-transfer equation which complies with a total energy balance. The latter description hinges on regularity theory for the fourth order p-Laplacian which induces regularity estimates of the deformation beyond the standard estimates available from energy bounds. Besides being crucial for the proof, these extra regularity properties might be of independent interest and seem to be new in the setting of nonlinear viscoelasticity, also in the static or quasi-static case.


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