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On a computational approach to multiple contacts / impacts of elastic bodies

Vala, Jiří, Rek, Václav (2023)

Programs and Algorithms of Numerical Mathematics

The analysis of dynamic contacts/impacts of several deformable bodies belongs to both theoretically and computationally complicated problems, because of the presence of unpleasant nonlinearities and of the need of effective contact detection. This paper sketches how such difficulties can be overcome, at least for a model problem with several elastic bodies, using i) the explicit time-discretization scheme and ii) the finite element technique adopted to contact evaluations together with iii) the...

On a new computational algorithm for impacts of elastic bodies

Hynek Štekbauer, Ivan Němec, Rostislav Lang, Daniel Burkart, Jiří Vala (2022)

Applications of Mathematics

Computational modelling of contact problems is still one of the most difficult aspects of non-linear analysis in engineering mechanics. The article introduces an original efficient explicit algorithm for evaluation of impacts of bodies, satisfying the conservation of both momentum and energy exactly. The algorithm is described in its linearized 2-dimensional formulation in details, as open to numerous generalizations including 3-dimensional ones, and supplied by numerical examples obtained from...

On a type of Signorini problem without friction in linear thermoelasticity

Jiří Nedoma (1983)

Aplikace matematiky

In the paper the Signorini problem without friction in the linear thermoelasticity for the steady-state case is investigated. The problem discussed is the model geodynamical problem, physical analysis of which is based on the plate tectonic hypothesis and the theory of thermoelasticity. The existence and unicity of the solution of the Signorini problem without friction for the steady-state case in the linear thermoelasticity as well as its finite element approximation is proved. It is known that...

On an elasto-dynamic evolution equation with non dead load and friction

Oanh Chau (2006)

Applications of Mathematics

In this paper, we are interested in the dynamic evolution of an elastic body, acted by resistance forces depending also on the displacements. We put the mechanical problem into an abstract functional framework, involving a second order nonlinear evolution equation with initial conditions. After specifying convenient hypotheses on the data, we prove an existence and uniqueness result. The proof is based on Faedo-Galerkin method.

On an interaction of two elastic bodies: analysis and algorithms

Ivona Svobodová (2012)

Applications of Mathematics

The paper deals with existence and uniqueness results and with the numerical solution of the nonsmooth variational problem describing a deflection of a thin annular plate with Neumann boundary conditions. Various types of the subsoil and the obstacle which influence the plate deformation are considered. Numerical experiments compare two different algorithms.

On finite element uniqueness studies for Coulombs frictional contact model

Patrick Hild (2002)

International Journal of Applied Mathematics and Computer Science

We are interested in the finite element approximation of Coulomb's frictional unilateral contact problem in linear elasticity. Using a mixed finite element method and an appropriate regularization, it becomes possible to prove existence and uniqueness when the friction coefficient is less than Cε^{2}|log(h)|^{-1}, where h and ε denote the discretization and regularization parameters, respectively. This bound converging very slowly towards 0 when h decreases (in comparison with the already known...

On harmonic disturbance rejection of an undamped Euler-Bernoulli beam with rigid tip body

Bao-Zhu Guo, Qiong Zhang (2004)

ESAIM: Control, Optimisation and Calculus of Variations

A hybrid flexible beam equation with harmonic disturbance at the end where a rigid tip body is attached is considered. A simple motor torque feedback control is designed for which only the measured time-dependent angle of rotation and its velocity are utilized. It is shown that this control can impel the amplitude of the attached rigid tip body tending to zero as time goes to infinity.

On harmonic disturbance rejection of an undamped Euler-Bernoulli beam with rigid tip body

Bao-Zhu Guo, Qiong Zhang (2010)

ESAIM: Control, Optimisation and Calculus of Variations

A hybrid flexible beam equation with harmonic disturbance at the end where a rigid tip body is attached is considered. A simple motor torque feedback control is designed for which only the measured time-dependent angle of rotation and its velocity are utilized. It is shown that this control can impel the amplitude of the attached rigid tip body tending to zero as time goes to infinity.

On Signorini problem for von Kármán equations. The case of angular domain

Jan Franců (1979)

Aplikace matematiky

The paper deals with the generalized Signorini problem. The used method of pseudomonotone semicoercive operator inequality is introduced in the paper by O. John. The existence result for smooth domains from the paper by O. John is extended to technically significant "angular" domains. The crucial point of the proof is the estimation of the nonlinear term which appears in the operator form of the problem. The substantial technical difficulties connected with non-smoothness of the boundary are overcome...

On the dynamical behaviour of plates in unilateral contact with an elastic foundation: a finite element approach.

Luigi Ascione, Domenico Bruno, Renato S. Olivito (1984)

Atti della Accademia Nazionale dei Lincei. Classe di Scienze Fisiche, Matematiche e Naturali. Rendiconti Lincei. Matematica e Applicazioni

In questo lavoro viene studiato il comportamento dinamico di una piastra vincolata monolateralmente su una fondazione elastica alla Winkler. Si presentano alcuni risultati numerici ottenuti mediante discretizzazione agli elementi finiti. Tali risultati mettono in luce l'influenza di alcuni fattori tipici come le funzioni di forma, il parametro di mesh e l'ampiezza dell'intervallo con cui si realizza l'integrazione nel tempo delle equazioni del moto. Si istituiscono infine dei confronti con risultati...

On the Signorini problem with friction in linear thermoelasticity: The quasi-coupled 2D-case

Jiří Nedoma (1987)

Aplikace matematiky

The Signorini problem with friction in quasi-coupled linear thermo-elasticity (the 2D-case) is discussed. The problem is the model problem in the geodynamics. Using piecewise linear finite elements on the triangulation of the given domain, numerical procedures are proposed. The finite element analysis for the Signorini problem with friction on the contact boundary Γ α of a polygonal domain G ⊂ R 2 is given. The rate of convergence is proved if the exact solution is sufficiently regular.

On the solution of a finite element approximation of a linear obstacle plate problem

Luis Fernandes, Isabel Figueiredo, Joaquim Júdice (2002)

International Journal of Applied Mathematics and Computer Science

In this paper the solution of a finite element approximation of a linear obstacle plate problem is investigated. A simple version of an interior point method and a block pivoting algorithm have been proposed for the solution of this problem. Special purpose implementations of these procedures are included and have been used in the solution of a set of test problems. The results of these experiences indicate that these procedures are quite efficient to deal with these instances and compare favourably...

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