Remarks about a Constructive Method in Nonlinear Elasticity

2019 ◽  
Author(s):  
Hans-Peter Gittel ◽  
Matthias Guenther

The paper deals with an incremental method for solving the equilibrium conditions in nonlinear elasticity which was introduced by H. Beckert in 1975. Here, the alteration rate of some stress tensor is prescribed by supplementary stresses. This yields an expression for a locally defined elastic energy and the total energy can be minimized. Hence, the considered method is in the sense of minimizing movements. The authors analyze some of its properties, derive a local existence result in a simplified way, and prove the convergence of an approximation scheme.

2019 ◽  
Vol 25 ◽  
pp. 8 ◽  
Author(s):  
Thomas Gallouët ◽  
Maxime Laborde ◽  
Léonard Monsaingeon

In this paper, we show that unbalanced optimal transport provides a convenient framework to handle reaction and diffusion processes in a unified metric setting. We use a constructive method, alternating minimizing movements for the Wasserstein distance and for the Fisher-Rao distance, and prove existence of weak solutions for general scalar reaction-diffusion-advection equations. We extend the approach to systems of multiple interacting species, and also consider an application to a very degenerate diffusion problem involving a Gamma-limit. Moreover, some numerical simulations are included.


2020 ◽  
Vol 361 ◽  
pp. 106912 ◽  
Author(s):  
Matthew J. Gursky ◽  
Gábor Székelyhidi

2004 ◽  
Vol 01 (04) ◽  
pp. 691-724 ◽  
Author(s):  
D. TEGANKONG ◽  
N. NOUTCHEGUEME ◽  
A. D. RENDALL

We prove in the cases of spherical, plane and hyperbolic symmetry a local in time existence theorem and continuation criteria for cosmological solutions of the Einstein–Vlasov-scalar field system, with the sources generated by a distribution function and a scalar field, subject to the Vlasov and wave equations respectively. This system describes the evolution of self-gravitating collisionless matter and scalar waves within the context of general relativity. In the case where the only source is a scalar field it is shown that a global existence result can be deduced from the general theorem.


1996 ◽  
Vol 119 (4) ◽  
pp. 739-762 ◽  
Author(s):  
Gerhard Rein

AbstractThe Vlasov-Einstein system describes a self-gravitating, collisionless gas within the framework of general relativity. We investigate the initial value problem in a cosmological setting with spherical, plane, or hyperbolic symmetry and prove that for small initial data solutions exist up to a spacetime singularity which is a curvature and a crushing singularity. An important tool in the analysis is a local existence result with a continuation criterion saying that solutions can be extended as long as the momenta in the support of the phase-space distribution of the matter remain bounded.


Author(s):  
Reinhard Racke ◽  
Belkacem Said-Houari

We consider the Cauchy problem of a third order in time nonlinear equation known as the Jordan–Moore–Gibson–Thompson (JMGT) equation arising in acoustics as an alternative model to the well-known Kuznetsov equation. We show a local existence result in appropriate function spaces, and, using the energy method together with a bootstrap argument, we prove a global existence result for small data, without using the linear decay. Finally, polynomial decay rates in time for a norm related to the solution will be obtained.


2011 ◽  
Vol 21 (08) ◽  
pp. 1733-1760 ◽  
Author(s):  
XIANMIN XU ◽  
DUVAN HENAO

This paper is concerned with the numerical computation of cavitation in nonlinear elasticity. The Crouzeix–Raviart nonconforming finite element method is shown to prevent the degeneration of the mesh provoked by the conventional finite element approximation of this problem. Upon the addition of a suitable stabilizing term to the elastic energy, the method is used to solve cavitation problems in both radially symmetric and non-radially symmetric settings. While the radially symmetric examples serve to illustrate the efficiency of the method, and for validation purposes, the experiments with non-centered and multiple cavities (carried out for the first time) yield novel observations of situations potentially leading to void coalescence.


Filomat ◽  
2021 ◽  
Vol 35 (5) ◽  
pp. 1745-1773
Author(s):  
Salah Boulaaras ◽  
Abdelbaki Choucha ◽  
Djamel Ouchenane

In this paper, we consider the Cauchy problem of a third order in time nonlinear equation known as the Jordan-Moore-Gibson-Thompson (JMGT) equation with the presence of both memory. Using the well known energy method combined with Lyapunov functionals approach, we prove a general decay result, and we show a local existence result in appropriate function spaces. Finally, we prove a global existence result for small data, and we prove the uniqueness of the generalized solution.


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