Band gaps in the relaxed linear micromorphic continuum

In this note we show that the relaxed linear micromorphic model recently proposed by the authors can be suitably used to describe the presence of band-gaps in metamaterials with microstructures in which strong contrasts of the mechanical properties are present (e.g. phononic crystals and lattice structures). This relaxed micromorphic model only has 6 constitutive parameters instead of 18 parameters needed in Mindlin- and Eringen-type classical micromorphic models. We show that the onset of band-gaps is related to a unique constitutive parameter, the Cosserat couple modulus $\mu_{c}$ which starts to account for band-gaps when reaching a suitable threshold value. The limited number of parameters of our model, as well as the specific effect of some of them on wave propagation can be seen as an important step towards indirect measurement campaigns

Le virus de Newcastle chez le Porc

Placidi Louis. Le virus de Newcastle chez le Porc. In: Bulletin de l'Académie Vétérinaire de France tome 107 n°7, 1954. pp. 375-377

Le Hérisson (Athtechinus algirus algirus) n'est pas réceptif au virus de Sanarelli (Myxome infectieux du Lapin)

Placidi Louis. Le Hérisson (Athtechinus algirus algirus) n’est pas réceptif au virus de Sanarelli (Myxome infectieux du Lapin). In: Bulletin de l'Académie Vétérinaire de France tome 110 n°6, 1957. pp. 281-283

Sur la vaccination contre la maladie de Newcastle par virus « vivant ». Note complémentaire

Placidi Louis. Sur la vaccination contre la maladie de Newcastle par virus «vivant». (Note complémentaire.). In: Bulletin de l'Académie Vétérinaire de France tome 112 n°7, 1959. pp. 443-445

Identification of a geometrically nonlinear micromorphic continuum via granular micromechanics

Describing the emerging macro-scale behavior by accounting for the micro-scale phenomena calls for microstructure-informed continuum models accounting properly for the deformation mechanisms identifiable at the micro-scale. Classical continuum theory, in contrast to the micromorphic continuum theory, is unable to take into account the effects of complex kinematics and distribution of elastic energy in internal deformation modes within the continuum material point. In this paper, we derive a geometrically nonlinear micromorphic continuum theory on the basis of granular mechanics, utilizing grain-scale deformation as the fundamental building block. The definition of objective kinematic descriptors for relative motion is followed by Piola’s ansatz for micro–macro-kinematic bridging and, finally, by a limit process leading to the identification of the continuum stiffness parameters in terms of few micro-scale constitutive quantities. A key aspect of the presented approach is the identification of relevant kinematic measures that describe the deformation of the continuum body and link it to the micro-scale deformation. The methodology, therefore, has the ability to reveal the connections between the micro-scale mechanisms that store elastic energy and lead to particular emergent behavior at the macro-scale

Sur une infection pulmonaire, contagieuse, endémique, du Porc rapportée à un ultra -virus, indépendante de la peste

Placidi Louis. Sur une infection pulmonaire, contagieuse, endémique, du Porc rapportée à un ultra-virus, indépendante de la peste. In: Bulletin de l'Académie Vétérinaire de France tome 109 n°1, 1956. pp. 59-65

La « blue-tongue » au Maroc

Placidi Louis. La “ Blue-tongue ” au Maroc. In: Bulletin de l'Académie Vétérinaire de France tome 110 n°2, 1957. pp. 79-84

Influence de la cortisone sur la réaction allergique à la tuberculine

Placidi Louis, Saunié Lucien. Influence de la cortisone sur la réaction allergique à la tuberculine. In: Bulletin de l'Académie Vétérinaire de France tome 114 n°1, 1961. pp. 63-67

Sur la sensibilisation à la tuberculine

Placidi Louis, Saunié Lucien. Sur la sensibilisation à la tuberculine. In: Bulletin de l'Académie Vétérinaire de France tome 114 n°1, 1961. pp. 69-76