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Item Characterization approaches affect asymmetric load predictions of hexagonal close-packed alloyAutores: Tuninetti, V.; Oñate, A.; Valenzuela, M.; Sepúlveda, H.; Pincheira Orellana, Gonzalo Omar; Medina, C.; García Herrera, C.; Duchene, L.; Habraken, A. M.The anisotropic plasticity constants of the CPB06 criterion for Ti64, previously identified with experiments performed in all three dimensions, are applied here to evaluate the effect of the direct and inverse calibration strategies of the tensile-compression asymmetry parameter k on the predictive behavior of large deformations of the hexagonal close-packed (hcp) alloy. The direct calibration strategy is based on model fitting with experimental strain hardening data up to the onset of plastic instability. The inverse calibration strategy reduces prediction errors of the load-displacement curves of both the cylindrical bar tensile and the elliptical cylinder compression tests. The results provide interesting insights into the identification of the laws modeling large deformations of hcp materials.Item Supersymmetry of a different kindAutores: Alvarez, P.D.; Valenzuela, M.; Zanelli, J.A local supersymmetric action for a (2+1)-dimensional system including gravity, the electromagnetic field and a Dirac spin-1/2 field is presented. The action is a Chern-Simons form for a connection of the OSp(2|2) group. All the fields enter as parts of the connection, that transforms in the adjoint representation of the gauge group. The system is off-shell invariant under local (gauge) supersymmetry. Although the supersymmetry is locally realized, there is no spin-3/2 gravitino, and is therefore not supergravity. The fields do not necessarily form supersymmetric doublets of equal mass, and moreover, the fermion may acquire mass through the coupling with geometry, while the bosons - the U(1) field and the spin connection - remain massless.
