Contacto intermitente y localizado entre dos superficies. Aplicación al caso de la interacción pastilla-vaina (PCI) en un combustible nuclear de potencia

Abstract

This work contains a study of an algorithm devised to analyze problems of contact between two materials separated by a gap, alternatively open and close. In the finite element scheme used the contact is expressed by restrictions. An approximation of incomplete field is employed; the domain is divided in two subdomains, in each of which an irreducible formulation in the displacements is used. Lagrange multipliers are used for the treatment of forces in the boundary between the subdomains. The calculation scheme derives from the virtual work principle, assuming continuity for the displacements at the boundary. The contact algorithm is tested in general problems with plane or axial symmetry, with well known analytical solution. Then it is applied to the simulation of the behavior of a nuclear fuel rod subjected to a postulated power history where the problem of pellet- cladding contact may arise. INTERMITENT AND LOCAL CONTACT BETWEEN TWO SURFACES. APPLICATION TO THE CASE OF PELLET-CLADDING INTERACTION (PCI) IN A NUCLEAR POWER FUEL ROD.

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