Daniel Goeleven

A stability theory for second-order nonsmooth dynamical systems with application to friction problems

Abstract A LaSalles Invariance Theory for a class of first-order evolution variational inequalities is developed. Using this approach, stability and asymptotic properties of important classes of second-order dynamic systems are studied. The theoretical results of the paper are supported by examples in nonsmooth Mechanics and some numerical simulations.

Stability and instability matrices for linear evolution variational inequalities

This paper deals with the characterization of the stability and instability matrices for a class of unilaterally constrained dynamical systems, represented as linear evolution variational inequalities (LEVI). Such systems can also be seen as a sort of differential inclusion, or (in special cases) as linear complementarity systems, which in turn are a class of hybrid dynamical systems. Examples show that the stability of the unconstrained system and that of the constrained system, may drastically differ. Various criteria are proposed to characterize the stability or the instability of LEVI.

Higher order Moreau's sweeping process: mathematical formulation and numerical simulation

In this paper we present an extension of Moreau’s sweeping process for higher order systems. The dynamical framework is carefully introduced, qualitative, dissipativity, stability, existence, regularity and uniqueness results are given. The time-discretization of these nonsmooth systems with a time-stepping algorithm is also presented. This differential inclusion can be seen as a mathematical formulation of complementarity dynamical systems with arbitrary dimension and arbitrary relative degree between the complementary-slackness variables. Applications of such high-order sweeping processes can be found in dynamic optimization under state constraints and electrical circuits with ideal diodes.

Dynamic hemivariational inequalities and their applications

Dynamic hemivariational inequalities are studied in the present paper. Starting from their solution in the distributional sense, we give certain existence and approximation results by using the Faedo–Galerkin method and certain compactness arguments. Applications from mechanics (viscoelasticity) illustrate the theory.

A qualitative mathematical analysis of a class of linear variational inequalities via semi-complementarity problems: applications in electronics

The main object of this paper is to present a general mathematical theory applicable to the study of a large class of linear variational inequalities arising in electronics. Our approach uses recession tools so as to define a new class of problems that we call “semi-complementarity problems”. Then we show that the study of semi-complementarity problems can be used to prove new qualitative results applicable to the study of linear variational inequalities of the second kind.

The Krakovskii-LaSalle Invariance Principle for a Class of Unilateral Dynamical Systems

Abstract.This paper is devoted to the study of the extension of the invariance lemma to a class of hybrid dynamical systems, namely evolution variational inequalities. Applications can be found in models of electrical circuits with ideal diodes or oligopolistic market equilibrium.

Semicoercive variational hemivariational inequalities

The aim of this paper is the mathematical study of a general class of semicoercive variational hemivariational inequalities introduced by P.D. Panagiotopoulos in order to formulate problems of mechanics involving nonconvex and nonsmooth energy function. Our approach is based on the asymptotic behavior of the functions which are involved in the variational problems.

Reduction of Second Order Unilateral Singular Systems. Applications in Mechanics

The aim of this paper is to discuss the mathematical strategies permitting the treatment of second order unilateral systems involving singular mass, damping, and stiffness matrices. Reduction methods are used here to transform second order differential inclusions in first order ones and classical results on differential inclusions are considered in order to obtain solutions. Friction and impact problems arising in Unilateral Mechanics are studied so as to illustrate the theoretical approach.

Homoclinic orbits for a class of hemivariational inequalities

Using a new compact imbedding theorem of C. De Coster and M.Willem [5], we prove the existence of homoclinic orbits for a class of hemivariational inequalities.

Hyperbolic Hemivariational Inequality and Nonlinear Wave Equation with Discontinuities

The paper presents existence results for solutions to a nonsmooth hyperbolic problem in the form of a hemivariational inequality separately in the nonresonant and resonant cases.