A finite element analysis for the Signorini problem in plane elastostatics
Two problems are considered describing dynamic processes for a class of rate-type elastic-viscoplastic materials with or without internal state variable. The existence and uniqueness of the solution is proved using classical results of linear elasticity theory together with a fixed point method.
In this paper the contact problem for a cylindrical shell and a stiff punch is studied. The existence and uniqueness of a solution is verified. The finite element method is discussed.
The tetrahedral stress element is introduced and two different types of a finite piecewise linear approximation of the dual elasticity problem are investigated on a polyhedral domain. Fot both types a priori error estimates in -norm and in -norm are established, provided the solution is smooth enough. These estimates are based on the fact that for any polyhedron there exists a strongly regular family of decomprositions into tetrahedra, which is proved in the paper, too.
We prove -regularity for the stresses in the Prandtl-Reuss-law. The proof runs via uniform estimates for the Norton-Hoff-approximation.
We prove that the classical Prandtl, Ishlinskii and Preisach hysteresis operators are continuous in Sobolev spaces for , (localy) Lipschitz continuous in and discontinuous in for arbitrary . Examples show that this result is optimal.
In questo articolo si studia un problema misto al contorno associato con le deformazioni finite di un parallelepipedo elastico incomprimibile, omogeneo ed isotropo. L'analisi è rivolta allo studio degli appoggi in gomma nelle costruzioni. In particolare, usando il metodo semi-inverso, viene fornita una soluzione esatta del problema di equilibrio degli appoggi semplicemente compressi. Inoltre, per ragioni di interesse tecnico, viene proposta una nuova relazione globale «carico-schiacciamento », che...