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We present a model for the dynamics of elastic or poroelastic bodies with monopolar repulsive long-range (electrostatic) interactions at large strains. Our model respects (only) locally the non-self-interpenetration condition but can cope…

Analysis of PDEs · Mathematics 2019-08-07 Tomas Roubicek , Giuseppe Tomassetti

We consider a class of models for nonlinearly elastic surfaces in this work. We have in mind thin, highly deformable structures modeled directly as two-dimensional nonlinearly elastic continua, accounting for finite membrane and bending…

Analysis of PDEs · Mathematics 2021-05-17 Timothy J. Healey

We consider gradient flow/gradient descent and heavy ball/accelerated gradient descent optimization for convex objective functions. In the gradient flow case, we prove the following: 1. If $f$ does not have a minimizer, the convergence…

Optimization and Control · Mathematics 2023-10-27 Jonathan W. Siegel , Stephan Wojtowytsch

We consider periodic homogenization of nonlinearly elastic composite materials. Under suitable assumptions on the stored energy function (frame indifference; minimality, non-degeneracy and smoothness at identity; $p\geq d$-growth from…

Analysis of PDEs · Mathematics 2018-07-25 Stefan Neukamm , Mathias Schäffner

Polyconvexity is one of the known conditions which guarantee existence of solutions of boundary value problems in finite elasticity. In this work we propose a framework for development of polyconvex strain energy functions for hyperelastic…

Materials Science · Physics 2007-05-23 N. Kambouchev , J. Fernandez , R. Radovitzky

We prove the local Lipschitz continuity and the higher differentiability of local minimizers of integral functionals with non autonomous integrand which is degenerate convex with respect to the gradient variable. The main novelty here is…

Analysis of PDEs · Mathematics 2019-06-07 Albert Clop , Raffaella Giova , Farhad Hatami , Antonia Passarelli di Napoli

In the present work, two machine learning based constitutive models for finite deformations are proposed. Using input convex neural networks, the models are hyperelastic, anisotropic and fulfill the polyconvexity condition, which implies…

Materials Science · Physics 2021-11-29 Dominik K. Klein , Mauricio Fernández , Robert J. Martin , Patrizio Neff , Oliver Weeger

The convergence behavior of gradient methods for minimizing convex differentiable functions is one of the core questions in convex optimization. This paper shows that their well-known complexities can be achieved under conditions weaker…

Optimization and Control · Mathematics 2013-09-10 Hui Zhang , Wotao Yin

In nonlinear elasticity, finding the deformation of a material which minimizes a given stored energy density is a challenging calculus of variations problem which may fail to have minimizers: the energy optimal material forms infinitely…

Optimization and Control · Mathematics 2026-04-16 Didier Henrion , Milan Korda , Martin Kružík , Karolına Sehnalová

The plastic component of the deformation gradient plays a central role in finite kinematic models of plasticity. However, its characterization has been the source of extended debates in the literature and many important issues still remain…

Materials Science · Physics 2015-04-29 Celia Reina , Sergio Conti

It is interesting to study the stress concentration between two adjacent stiff inclusions in composite materials, which can be modeled by the Lam\'e system with partially infinite coefficients. To overcome the difficulty from the lack of…

Analysis of PDEs · Mathematics 2018-02-06 Yuanyuan Hou , Hongjie Ju , Haigang Li

New lattice model for the gradient elasticity is suggested. This lattice model gives a microstructural basis for second-order strain-gradient elasticity of continuum that is described by the linear elastic constitutive relation with the…

Materials Science · Physics 2015-01-08 Vasily E. Tarasov

Making the gradients small is a fundamental optimization problem that has eluded unifying and simple convergence arguments in first-order optimization, so far primarily reserved for other convergence criteria, such as reducing the…

Optimization and Control · Mathematics 2021-01-29 Jelena Diakonikolas , Puqian Wang

We compare several notion of weak (modulus of) gradient in metric measure spaces. Using tools from optimal transportation theory we prove density in energy of Lipschitz maps independenly of doubling and Poincar\'e assumptions on the metric…

Analysis of PDEs · Mathematics 2014-09-16 Luigi Ambrosio , Nicola Gigli , Giuseppe Savaré

This article is devoted to characterize all possible effective behaviors of composite materials by means of periodic homogenization. This is known as a $G$-closure problem. Under convexity and $p$-growth conditions ($p>1$), it is proved…

Analysis of PDEs · Mathematics 2015-06-26 Jean-Francois Babadjian , Marco Barchiesi

Experimental testing on dry woven fabrics exhibits a complex set of evidences that are difficult to be completely described using classical continuum models. The aim of this paper is to show how the introduction of energy terms related to…

Soft Condensed Matter · Physics 2016-09-16 Gabriele Barbagallo , Angela Madeo , Fabrice Morestin , Philippe Boisse

Preconditioning is a crucial operation in gradient-based numerical optimisation. It helps decrease the local condition number of a function by appropriately transforming its gradient. For a convex function, where the gradient can be…

Optimization and Control · Mathematics 2023-08-29 Dmitrii A. Pasechnyuk , Alexander Gasnikov , Martin Takáč

Tangent stabilised large strain isotropic elasticity was recently proposed by Poya et al. [1] wherein by working directly with principal stretches the entire eigenstructure of constitutive and geometric/initial stiffness terms were found in…

Computational Physics · Physics 2024-09-30 Roman Poya , Rogelio Ortigosa , Antonio J. Gil , Theodore Kim , Javier Bonet

Many problems in high-dimensional statistics and optimization involve minimization over nonconvex constraints-for instance, a rank constraint for a matrix estimation problem-but little is known about the theoretical properties of such…

Optimization and Control · Mathematics 2017-10-20 Rina Foygel Barber , Wooseok Ha

In this paper, we consider a class of variational problems with integral functionals involving nonlocal gradients. These models have been recently proposed as refinements of classical hyperelasticity, aiming for an effective framework to…

Analysis of PDEs · Mathematics 2025-09-04 Carolin Kreisbeck , Hidde Schönberger