Calcul des charges limites d'une structure élastoplastique en contraintes planes
Cartesian currents and variational problems for mappings into spheres
Computation of displacements for nonlinear elastic beam models using monotone iterations.
Constrained and unconstrained optimization formulations for structural elements in unilateral contact with an elastic foundation.
Contact between elastic bodies. III. Dual finite element analysis
The problem of a unilateral contact between elastic bodies with an apriori bounded contact zone is formulated in terms of stresses via the principle of complementary energy. Approximations are defined by means of self-equilibriated triangular block-elements and an -error estimate is proven provided the exact solution is regular enough.
Contact problems with bounded friction. Semicoercive case
Convergence analysis of the iterative methods for quasi-complementarity problems.
Convergence of an equilibrium finite element model for plane elastostatics
An equilibrium triangular block-element, proposed by Watwood and Hartz, is subjected to an analysis and its approximability property is proved. If the solution is regular enough, a quasi-optimal error estimate follows for the dual approximation to the mixed boundary value problem of elasticity (based on Castigliano's principle). The convergence is proved even in a general case, when the solution is not regular.
Critical points in the energy of hyperelastic materials
Curved composite beam with interlayer slip loaded by radial load
Elastic two-layer curved composite beam with partial shear interaction is considered. It is assumed that each curved layer separately follows the Euler-Bernoulli hypothesis and the load slip relation for the flexible shear connection is a linear relationship. The curved composite beam at one of the end cross sections is fixed and the other end cross section is subjected by a concentrated radial load. Two cases are considered. In the first case the loaded end cross section is closed by a rigid plate...
Densités d'énergie et matériaux cristallins
Dependence of the buckling load of a nonshallow arch with respect to the shape of its midcurve
Déplacements à déformations bornées et champs de contrainte mesures
Domain decomposition method and elastic multi-structures: the stiffened plate problem.
Dual finite element analysis for contact problem of elastic bodies with an enlarging contact zone
Dual finite element analysis of the contact problem of two elastic bodies with an enlarging contact zone is presented. Approximations of the solution are defined on two types of triangulations by piecewise constant stress fields. Convergence is proved in both cases.
Energy methods for curved composite beams with partial shear interaction
This paper presents a derivation of the Rayleigh- Betti reciprocity relation for layered curved composite beams with interlayer slip. The principle of minimum of potential energy is also formulated for two-layer curved composite beams and its applications are illustrated by numerical examples. The solution of the presented problems are obtained by the Ritz method. The applications of the Rayleigh-Betti reciprocity relation proven are illustrated by some examples.
Error estimates for the ultra weak variational formulation in linear elasticity
We prove error estimates for the ultra weak variational formulation (UWVF) in 3D linear elasticity. We show that the UWVF of Navier’s equation can be derived as an upwind discontinuous Galerkin method. Using this observation, error estimates are investigated applying techniques from the theory of discontinuous Galerkin methods. In particular, we derive a basic error estimate for the UWVF in a discontinuous Galerkin type norm and then an error estimate in the L2(Ω) norm in terms of the best approximation...
Error estimates for the ultra weak variational formulation in linear elasticity∗
We prove error estimates for the ultra weak variational formulation (UWVF) in 3D linear elasticity. We show that the UWVF of Navier’s equation can be derived as an upwind discontinuous Galerkin method. Using this observation, error estimates are investigated applying techniques from the theory of discontinuous Galerkin methods. In particular, we derive a basic error estimate for the UWVF in a discontinuous Galerkin type norm and then an error estimate...
Estensione di un teorema sull'adattamento in dinamica elasto-plastica
Nell'articolo si tratta il problema dell'adattamento in dinamica elasto-plastica. La trattazione è fondata sulle seguenti basi: si adotta un legame costitutivo elasto-plastico di notevole generalità, basato su di una formulazione a variabili interne in grado di descrivere un comportamento incrudente genericamente non lineare; si fa riferimento ad un modello strutturale discreto, descritto mediante variabili generalizzate. I contributi presentati si possono così riassumere: si estendono risultati...
Étude de transmission à travers des inclusions minces faiblement conductrice de «codimension un» : homogénéisation et optimisation des structures