Dinâmica não linear, caos, e controle na microscopia de força atômica

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Dinâmica não-linear de um sistema mono-pendular invertido, excitado por um vibrador eletrodinâmico de potência controlada

Pós-graduação em Engenharia Mecânica - FEB

Modelagem e simulação das juntas de um manipulador robótico cilíndrico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Suspensões de veículos - Um estudo de caso

Pós-graduação em Engenharia Mecânica - FEG

Estudo da dinâmica de captura em discos proto-planetários

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento de algoritmo para modelagem e simulação de sistemas por grafos de ligação

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Controle de dissociação molecular com ferramentas de dinâmica não linear

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Otimização dinâmica de rotores com eixos em compósito

Pós-graduação em Engenharia Mecânica - FEG

Análise dinâmica de mecanismo articulado de suspensão com não-linearidade na rigidez devido à geometria e à excitação por desbalanceamento rotativo na condição não ideal

Pós-graduação em Engenharia Mecânica - FEB

O Método de Kane aplicado a um modelo de corpo humano para obtenção da pressão intradiscal na coluna lombar

Nos últimos anos tem surgido vários métodos para se estudar sistemas multicorpos. A vantagem destes métodos é a obtenção das equações do movimento de forma mais fácil e precisa. Robôs, manipuladores, mecanismos, satélites, máquinas em geral e sistemas biomcânicos, pelas suas características, podem ser vantajosamente tratados por formalismo multicorpo, mas precisamente, o método de Kane a um modelo do corpo humano, com a finalidade de se determinar a pressão intradiscal entre as vértebras L4/L5 da coluna lombar, em algumas atividades normais de vida diária, como: sentar, abaixar, pegar e elevar cargas, realizar movimentos de flexão e extensão. Pretendeu-se, também obter os esforços internos nas diversas articulações deste modelo. A pressão intradiscal representa um parâmetro importante para caracterizar a sobrecarga na coluna, podendo ter relação com a degeneração do disco intervertebral, o que produz muita dor em indivíduos. Inicialmente, o modelo foi proposto e o método de Kane foi aplicado para se obter as equações do movimento. Para resolvê-las, foi necessário realiza a filmagem de um sujeito realizando as atividades citadas, a fim de se obter as equações das trajetórias dos diversos segmentos do corpo humano. Após a simulação, os parâmetros desejados foram obtidos e comparados com valores experimentais citados na literatura.

Satélites estabilizados por rotação e torque de radiação solar direta

The aims of this work are to analyze the direct solar radiation pressure torque (TPRS) in the rotational motion of spin-stabilized artificial satellites, to numerically implement these solutions and to compare the results with real data of the Brazilian Satellite Data Collection – SCD1 and SCD2, supplied by INPE. The mathematical model for this torque is determined for a cylindrical satellite, and the components of this torque are determined in a fixed system in the satellite. An analytical solution for the spin motion equations is proposed, in which TPRSD does not affect the spin velocity of the satellite. Two approaches are adopted in the numerical implementation of the developed theory: the first one considers the proposed theory and the second introduces a variation in the spin velocity based on its real variation. The results obtained indicate that the solar radiation pressure torque has little influence in the right ascension and declination axis of rotation due to the small dimension of the satellite and altitude in which it is found. To better validate the application of the presented theory, the angular deviation of the spin axis and solar aspect angle were also analyzed. The comparison of the results of the approaches conducted with real data show good precision in the theory, which can be applied in the prediction of the rotational motion of the spin-stabilized artificial satellites, when others external torques are considered besides the direct solar radiation pressure torque

Estudo da estabilidade dinâmica e controle da aeronave AF-X da equipe AeroFEG

The present work aims to study the stability and control of the aircraft AF-X of AeroFEG team for AeroDesign to contribute with it in developing its theoretical project report for the competition and present the shortcomings of stability that it might measures for the practical test. In the first moment, it was presented forces and motion of the aircraft, so to define the equations of motion. After the equations of motion were calculated, the transfer functions were found and the aircraft response was analyzed under longitudinal stability and lateral-directional. We obtained responses from the aircraft and through the method of Root Locus the gains required to improve responses and reduce the overshoot, finally some changes and improvements for increased stability have been addressed. The study covered all the motions and control surfaces of the aircraft, showing the characteristics and behavior of the front disruptions, as well as opportunities for gains and improvementsThe present work aims to study the stability and control of the aircraft AF-X of AeroFEG team for AeroDesign to contribute with it in developing its theoretical project report for the competition and present the shortcomings of stability that it might measures for the practical test. In the first moment, it was presented forces and motion of the aircraft, so to define the equations of motion. After the equations of motion were calculated, the transfer functions were found and the aircraft response was analyzed under longitudinal stability and lateral-directional. We obtained responses from the aircraft and through the method of Root Locus the gains required to improve responses and reduce the overshoot, finally some changes and improvements for increased stability have been addressed. The study covered all the motions and control surfaces of the aircraft, showing the characteristics and behavior of the front disruptions, as well as opportunities for gains and improvements

Reanálise das defasagens de Prometeu e Pandora

In the present work it is proposed to do a revision on some studies on the dynamics of the Prometheus-Pandora system. In special, those studies that deal with anomalous behaviours observed on its components, identi ed as angular lags in these satellite`s orbits. Initially, it is presented a general description, contextualising the main characteristics of this system. The main publications related to this subject are analised and commented, in chronological order, showing the advances made in the knowledge of such dynamics. An analysis of the initial conditions, used by Goldreich e Rappaport (2003a ,b) e Cruz (2004), obtained through observations made by the Voyager 1 and 2 spacecrafts and by the Hubble space telescope, it is made in order to try to reproduce their results. However, no clear conclusion of the values used were found. The tests addopted in the analysis are from Cruz (2004), which reproduced the results and o ered a new explanation on the origin of the observed angular lags. The addopetd methodology involves the numerical integration of the equations of motion of the system, including the zonal harmonics J2, J4 and J6 of Saturn's gravitational potential. A fundamental consideration in this study is the use of geometric elements instead of osculating elements. It was found the set of initial data that best reproduces the results from Goldreich e Rappaport (2003a, b) and Cruz (2004)

Controle ativo de vibrações em vigas utilizando controle feedforward e elementos espectrais

Pós-graduação em Engenharia Mecânica - FEB

Transformações de Bäcklund para hierarquias integráveis abelianas

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)