Titre :	Sistemas de isolamento vibracional e de acoplamento antena-transdutores para o protótipo de um detector de ondas gravitacionais
Type de document :	texte imprimé
Auteurs :	José Luiz Melo, Auteur ; Walter Ferreira Jr. Velloso, Directeur de thèse ; Odylio Denys de Aguiar, Directeur de thèse ; National Institute For Space Research (São José dos Campos, Brésil), Organisme de soutenance
Editeur :	s.l. : [s.n.]
Année de publication :	2002
Importance :	1 volume (192 feuilles)
Présentation :	illustrations en noir et blanc et an couleur
Format :	30 cm
Accompagnement :	1 CD-ROM
Note générale :	PPN 294057137 Thèse : Astrophysique : São José dos Campos, Brésil : 2002 Remarque : Cette notice a été créée suite à un don. Cet exemplaire ne porte pas de numéro national de thèse
Langues :	Portugais (por)
Tags :	Ondes gravitationnelles -- Thèses et écrits académiques  Ondes gravitationnelles -- Instruments -- Thèses et écrits académiques  Méthode des éléments finis -- Thèses et écrits académiques  Gravitational waves -- Thesis  Gravitational waves -- Instruments -- Thesis  Finite element method -- Thesis
Index. décimale :	530.14 Théorie des champs et théorie ondulatoire
Résumé :	The GRAVITON group is building the first Brazilian gravitational wave detector prototype. This detector, which will be named MARIO SCHENBERG, will be composed by a a 65 cm diameter CuAl(6%) resonant spherical mass. This mass will weight 1.15 ton and will have a high mechanical Q (~ 20 million). This detector will be sensitive from 3100 Hz to 3300 Hz. In this work, the vibration isolation system, the thermal link and the transducer mechanical structure were conceived and numerical analysed. To the numerical analyses the conceived systems were represented by finite element models and the corresponding dynamical equations were solved using the Msc/Nastran software. This software was validated using measurements of the normal modes made at room temperature for an Al5056 25cm diameter resonant mass. The validation results showed a 4,26% maximum differerence between the normal modes measurements and calculations. The methodology used (Velloso, Melo & Aguiar; 2000) consists basically on evaluate all the structure elements separately and after that integrate them in such a manner to obey a mechanical behaviour optimization. In the case of the vibration isolation system the optimization consists to increase the window free of resonances around the detector characteristics frequencies. With this procedure we obtained a window free of resonances from 2625 Hz to 3768 Hz, with a 280 dB attenuation (Melo, Velloso & Aguiar, 2001). An analogous methodology was used to design the thermal link, which will be used to cool down all the structure to milikelvins. A prototype of this thermal link was constructed and tested using a cryogenic testfacility in the AURIGA laboratories in the National Institute for Nuclear Research (INFN) at Padova (Italia). We obtained a 30 dB attenuation to this prototype. It was also made a study about the sphere transducer coupling. In this case, the analysis was made in a way to sintonize the sphere and the transducers. The transducer frequency obtained was at 3190 Hz (Frajuca, Melo et al.; 2001). At last, it was made the integration of the several systems analysed: vibration isolation system, thermal link and the coupling transducer-resonant mass in order to study the overall system behavior and the noise influence over it. It continued to occur the 280 dB atenuation.
Note de contenu :	Bibliographie feuilles 158-168

Sistemas de isolamento vibracional e de acoplamento antena-transdutores para o protótipo de um detector de ondas gravitacionais [texte imprimé] / José Luiz Melo, Auteur ; Walter Ferreira Jr. Velloso, Directeur de thèse ; Odylio Denys de Aguiar, Directeur de thèse ; National Institute For Space Research (São José dos Campos, Brésil), Organisme de soutenance . - s.l. : [s.n.], 2002 . - 1 volume (192 feuilles) : illustrations en noir et blanc et an couleur ; 30 cm + 1 CD-ROM.
PPN 294057137
Thèse : Astrophysique : São José dos Campos, Brésil : 2002
Remarque : Cette notice a été créée suite à un don. Cet exemplaire ne porte pas de numéro national de thèse
Langues : Portugais (por)

Tags :	Ondes gravitationnelles -- Thèses et écrits académiques  Ondes gravitationnelles -- Instruments -- Thèses et écrits académiques  Méthode des éléments finis -- Thèses et écrits académiques  Gravitational waves -- Thesis  Gravitational waves -- Instruments -- Thesis  Finite element method -- Thesis
Index. décimale :	530.14 Théorie des champs et théorie ondulatoire
Résumé :	The GRAVITON group is building the first Brazilian gravitational wave detector prototype. This detector, which will be named MARIO SCHENBERG, will be composed by a a 65 cm diameter CuAl(6%) resonant spherical mass. This mass will weight 1.15 ton and will have a high mechanical Q (~ 20 million). This detector will be sensitive from 3100 Hz to 3300 Hz. In this work, the vibration isolation system, the thermal link and the transducer mechanical structure were conceived and numerical analysed. To the numerical analyses the conceived systems were represented by finite element models and the corresponding dynamical equations were solved using the Msc/Nastran software. This software was validated using measurements of the normal modes made at room temperature for an Al5056 25cm diameter resonant mass. The validation results showed a 4,26% maximum differerence between the normal modes measurements and calculations. The methodology used (Velloso, Melo & Aguiar; 2000) consists basically on evaluate all the structure elements separately and after that integrate them in such a manner to obey a mechanical behaviour optimization. In the case of the vibration isolation system the optimization consists to increase the window free of resonances around the detector characteristics frequencies. With this procedure we obtained a window free of resonances from 2625 Hz to 3768 Hz, with a 280 dB attenuation (Melo, Velloso & Aguiar, 2001). An analogous methodology was used to design the thermal link, which will be used to cool down all the structure to milikelvins. A prototype of this thermal link was constructed and tested using a cryogenic testfacility in the AURIGA laboratories in the National Institute for Nuclear Research (INFN) at Padova (Italia). We obtained a 30 dB attenuation to this prototype. It was also made a study about the sphere transducer coupling. In this case, the analysis was made in a way to sintonize the sphere and the transducers. The transducer frequency obtained was at 3190 Hz (Frajuca, Melo et al.; 2001). At last, it was made the integration of the several systems analysed: vibration isolation system, thermal link and the coupling transducer-resonant mass in order to study the overall system behavior and the noise influence over it. It continued to occur the 280 dB atenuation.
Note de contenu :	Bibliographie feuilles 158-168