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Previous issue date: 2016-05-02 / O n?mero de implantes e a prefer?ncia dos mesmos em rela??o ?s pr?teses v?m crescendo a cada ano no Brasil, assim como os profissionais habilitados para tal procedimento. Com isso, ? necess?rio que haja estudos sistem?ticos sobre a din?mica que ocorre entre o par osso-metal no sistema. Utilizou-se osso su?no para a confec??o dos corpos-de-prova devido ao f?cil acesso ao material. Ensaiou-se e submeteu-se em laborat?rio o sistema a esfor?os de flexo-tor??o, quantificando-se o "backlash" (folga) ap?s 10^5 ciclos. Investigou-se tamb?m danos na estrutura ?ssea devido ?s solicita??es mec?nicas c?clicas aplicadas. Tamb?m se avaliou microscopicamente o conjunto parafuso-porca. Este estudo possibilitou identificar que a temperatura registrada durante a maioria dos ensaios manteve-se numa faixa entre 20 e 30?C, a acelera??o de vibra??o global e a press?o sonora demonstram que at? 10^4 ciclos o contato entre porca calota e parafuso da haste ? n?o conforme, com rugosidade elevada, confirmando a passagem pelo per?odo de running in do par tribol?gico metal-metal, enquanto que ap?s 10^4 ciclos h? o aumento par?metros, anteriormente citados, at? o t?rmino do ensaio, passando a existir um contato conforme no per?odo de regime permanente (steady steak). O Backlash mensurado identificou um valor m?ximo m?dio de 0,49mm. Debris, forma??o de proa, trincas e delamina??o foram observadas no MEV do osso e da porca-calota. O par osso-metal ainda foi submetido a um ensaio de tra??o, obtendo-se um gr?fico for?a versus deforma??o. / The number of implants and the preference of the same in relation to prostheses
have been growing every year in Brazil, as well as professionals for such a
procedure. With this, a systematic study is needed on the dynamic that occurs
between the pair bone-metal in the system. Swine?s bone was used for making
specimen due to easy access to the material. It was tested and subjected to
laboratory system flexo-torsional stresses, backlash was quantified after 105 cycles.
It also was investigated damage in the bone structure due to the applied cyclic
mechanical stress. Also microscopically assessed the screw-nut assembly. This
study identified that the temperature during most assays was maintained in a range
between 20 and 30 ? C, global vibration velocity and sound pressure showed that up
to 104 cycles, the contact between nut-cap and screw of the stem is counterformal
contact, with high roughness, confirming the passage of the running-in period or
tribological metal-metal pair softening, whereas after 104 cycles for increased
parameters mentioned above by the end the test, starting to be a contact as the
steady steak period. The measured Backlash identified a maximum value of 0.49
mm. Debris, prow formation, cracks and delamination were observed in SEM bone
and nut-cap. The metal-bone pair was also subjected to a tensile test, yielding a
graph force versus deformation.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/21684 |
| Date | 02 May 2016 |
| Creators | Sousa, Jo?o Andrade Lopes de |
| Contributors | 10973370491, Aquino, Marcos Silva de, 47426632415, Melo, Mois?s Vieira de, 10774556404, Souza, Juliana Ricardo de, 05844998413, Souza, Roberto Silva de, 44466927472, Medeiros, Jo?o Telesforo N?brega de |
| Publisher | PROGRAMA DE P?S-GRADUA??O EM ENGENHARIA MEC?NICA, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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