• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 24
  • 14
  • 7
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 63
  • 9
  • 9
  • 9
  • 8
  • 7
  • 7
  • 7
  • 7
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

"Os assuntos que discutimos são a cara da nossa luta" : um estudo antropológico dos debates feministas em meio às possibilidades de sociabilidade online

Silveira, Natália Alves Cardoso Orlandi January 2013 (has links)
Este trabalho se propõe a analisar a intersecção entre o feminismo e o mundo virtual, a partir da análise qualitativa de um coletivo feminista que abrange uma lista de discussão online e um blog coletivo, denominado Blogueiras Feministas. Partindo do pressuposto de que a internet abre caminhos e novas possibilidades de sociabilidade, pretendendo avaliar o quanto esse aspecto foi aproveitado por este coletivo virtual a partir de suas discussões e produções textuais. Indo de encontro ao ideário propagado no senso comum e em alguns setores de que o feminismo já seria um movimento morto ou relegado ao próprio fracasso, inicia-se a análise a partir de referenciais teóricos feministas que foram encontrados em campo, em especial Susan Faludi e sua conceituação de backlash, abordando a forma como a internet propicia novas formas de enfrentamento a esse retrocesso percebido. Passando, então, para a perspectiva do Sofrimento Social, por meio da Antropologia da Experiência, pretende-se investigar como tal auto atribuição identitária e mobilização política se intercruzam nos meios online e offline, deixando entrever como a violência estrutural de gênero ainda permeia o compartilhamento de experiências; e como de determinada perspectiva inclusiva passa-se à formativa, de novos conhecimentos e formas de reivindicação. Finalizando, com a abordagem de novas pautas que emergem e são assimiladas por esse movimento cuja preocupação com a inclusão se mostra basilar. / This paper aims at analyzing the intersection between the feminist world and the virtual world, through a qualitative analysis of a feminist group that comprises an online discussion list, and a collective blog, called “Blogueiras Feministas”. Starting from the assumption that the internet opens paths and new sociability possibilities, intending to evaluate how much this virtual group took advantage of this aspect through its discussions and text productions. Going against the idea, spread by common sense and by some sectors of society, that feminism is already either dead or relegated to its own failure, the analysis starts from some feminist theoretical references that were found in field, specially Susan Faludi and her conceptualization of backlash, addressing the manner in which the internet allows new forms of facing this perceived throwback. Thereafter, the perspective of the Social Suffering is treated. Through the Antropology of the Experience it is investigated how such identity auto attribution and political mobilization meet in both online and offline environments, allowing a glimpse of how the structural gender violence still permeates the sharing of experiences; and how a certain inclusive perspective gives place to a formative one, of new knowledges and new means of claim. Finally, there is the approach of new agendas that are emerging and that are assimilated by this movement whose concern about inclusion is basic ground.
22

GLOBALIZED BACKLASH: WOMEN AGAINST FEMINISM’S NEW MEDIA MATRIX OF (ANTI) FEMINIST TESTIMONY

Mapes, Margarethe 01 May 2016 (has links)
Feminisms are oftentimes confronted with dissonance, resistance, and backlash. Invested in criticizing the cultural and institutional emergence of patriarchy and calls to re-order structures of inequality make feminism threatening to status quo power dynamics. “Women Against Feminism”—a social media phenomenon and space for women to post anti-feminist messages—began gaining notoriety in 2013. By 2015, “Women Against Feminism” expanded to multiple social media platforms, gained thousands of anti-feminist submissions, and received ample support and criticism across news outlets. This study explores “Women Against Feminism” as a potential site of 21st feminist backlash, noting nuanced rhetorical strategies that rely on fearing feminism, declarations of interpersonal and intrapersonal love, and co-opting feminist ideology to propagate anti-feminist narratives. I situate backlash as a communicative phenomenon of perception rather than a clear-cut movement reacting toward a stated goal of progress by a social group. In this way, feminist progress functions as an illusory cultural script where backlash reacts toward the perceived enactment of a feminist goal, rather than (although not excluding) the successful feminist execution of that goal. Thus, this study dually investigates what backlash strategies are used while also uncovering how differing audiences perceive feminism. Finally, I set forth a series of suggestive practical methods for feminist engagement across dissonance and difference.
23

"Os assuntos que discutimos são a cara da nossa luta" : um estudo antropológico dos debates feministas em meio às possibilidades de sociabilidade online

Silveira, Natália Alves Cardoso Orlandi January 2013 (has links)
Este trabalho se propõe a analisar a intersecção entre o feminismo e o mundo virtual, a partir da análise qualitativa de um coletivo feminista que abrange uma lista de discussão online e um blog coletivo, denominado Blogueiras Feministas. Partindo do pressuposto de que a internet abre caminhos e novas possibilidades de sociabilidade, pretendendo avaliar o quanto esse aspecto foi aproveitado por este coletivo virtual a partir de suas discussões e produções textuais. Indo de encontro ao ideário propagado no senso comum e em alguns setores de que o feminismo já seria um movimento morto ou relegado ao próprio fracasso, inicia-se a análise a partir de referenciais teóricos feministas que foram encontrados em campo, em especial Susan Faludi e sua conceituação de backlash, abordando a forma como a internet propicia novas formas de enfrentamento a esse retrocesso percebido. Passando, então, para a perspectiva do Sofrimento Social, por meio da Antropologia da Experiência, pretende-se investigar como tal auto atribuição identitária e mobilização política se intercruzam nos meios online e offline, deixando entrever como a violência estrutural de gênero ainda permeia o compartilhamento de experiências; e como de determinada perspectiva inclusiva passa-se à formativa, de novos conhecimentos e formas de reivindicação. Finalizando, com a abordagem de novas pautas que emergem e são assimiladas por esse movimento cuja preocupação com a inclusão se mostra basilar. / This paper aims at analyzing the intersection between the feminist world and the virtual world, through a qualitative analysis of a feminist group that comprises an online discussion list, and a collective blog, called “Blogueiras Feministas”. Starting from the assumption that the internet opens paths and new sociability possibilities, intending to evaluate how much this virtual group took advantage of this aspect through its discussions and text productions. Going against the idea, spread by common sense and by some sectors of society, that feminism is already either dead or relegated to its own failure, the analysis starts from some feminist theoretical references that were found in field, specially Susan Faludi and her conceptualization of backlash, addressing the manner in which the internet allows new forms of facing this perceived throwback. Thereafter, the perspective of the Social Suffering is treated. Through the Antropology of the Experience it is investigated how such identity auto attribution and political mobilization meet in both online and offline environments, allowing a glimpse of how the structural gender violence still permeates the sharing of experiences; and how a certain inclusive perspective gives place to a formative one, of new knowledges and new means of claim. Finally, there is the approach of new agendas that are emerging and that are assimilated by this movement whose concern about inclusion is basic ground.
24

Vida eterna para os casamentos : a pedagogia evangelizadora da escola do amor da Igreja Universal do Reino de Deus

Bueno, Paulo Fernando Zanardini January 2017 (has links)
Esta dissertação, de abordagem qualitativa, e situada no campo dos Estudos Culturais em Educação, analisou nas falas dos apresentadores de um artefato cultural da televisão, o programa The Love School, os temas mais discutidos por eles. Como primeira técnica da metodologia utilizada, esse recurso gerou a fonte de material empírico registrado no que nominei de caderno de transcrições. Para realizar esta investigação selecionei 24 (vinte e quatro) edições do programa entre o período de novembro de 2014 a abril de 2015. O casamento é o principal tema que orienta a pauta deste programa e faz uma aliança direta com os princípios que fundamentam a Igreja Universal do Reino de Deus. Quanto ao programa The Love School foi possível entender que a Universal desenvolveu uma nova forma de falar de religião fazendo uso de outras linguagens como a linguagem própria da televisão, pois esse novo produto da grade de programação da Record TV, pode ter dado início a uma nova sequencia de programas televangelizadores, que, nas versões mais tradicionais e mais religiosas, parecem monótonos e desinteressantes pelo uso da linguagem comum aos púlpitos das catedrais e pelos horários de exibição cansativos das madrugadas. A categoria da pedagogia cultural, como um conceito caro para o campo da educação, nesse artefato cultural, pode ser percebida com uma outra dinâmica que não apenas a de ensinar modos de ser e de viver, pois demostrou que, conjuntamente a isso, pode também apontar o contraexemplo de outras pedagogias culturais em outros artefatos culturais, dessa vez os do entretenimento comercial. Compreendi essa atuação do conceito nesse objeto pela introdução da cultura religiosa com origem na Igreja criticando a cultura profana de outros produtos da mídia. Essa mesma discursividade molda um modelo de casal que prioriza o casamento acima de qualquer problema, devendo superar o menor dos desafios para impedir uma separação, e que se inspira no homem e na mulher presentes no texto bíblico, no Antigo Testamento, inspiração que é vista no contexto da análise aqui empregada como um retrocesso para a vida real das mulheres. A ideia de retrocesso ou de backlash (Faludi, 2001) parece ser um elemento que adere facilmente à cultura religiosa da Universal, aliando-se à pedagogia cultural ensinada pelo The Love School. O backlash tem como característica operar como uma política cultural em forma de ciclos. Ciclicamente, a cultura parece nos fazer viver muitos momentos de intenso retrocesso (backlash), tanto por meio de determinados produtos da mídia quanto pelas reações de determinados grupos políticos nos impondo seus interesses. Consequentemente, pelas análises que aqui empreendi e por essas características assumidas pela IURD, penso que vivemos no Brasil contemporâneo um ciclo religioso de backlash (retrocesso) para as coisas da vida e para as relações amorosas, para dizer o mínimo. / This qualitative approach master‘s dissertation on Educational Cultural Studies has analyzed the lines of the presenters of a cultural artifact of television, The Love School show, and the subjects most discussed by them. As the first technique of the methodology used, this resource generated the source of empirical material registered in what I named ―The Transcription Notebook‖. For the research, I have selected 24 (twenty four) editions of the show from November, 2014 to April, 2015. Marriage is the central theme of the show‘s agenda which is directly related to the principles underlying the Universal Church of the Kingdom of God. Through The love school show it was possible to realize that the Universal Church has developed a new way of talking about religion, by making use of other languages, such as the proper language of television, since this new product offered by the Record TV channel may have initiated a sequence of new evangelizing shows, which tend to be monotonous and uninteresting in their most traditional and religious versions due to the use of a language common to the cathedrals‘ pulpits as well as the tiresome show times. Such cultural artifact allow us to understand the concept of cultural pedagogy category, dear to the field of education, as a different dynamic that does not only teach ways of being and living, but also show the counterexample of other cultural pedagogies in another cultural artifacts, such as the commercial entertainment. I have understood this concept in such object through the introduction of the religious culture originating in the Church that criticizes the unholy culture of media products. This same discourse frames a standard of couple who prioritize marriage above any problem so as to overcome challenges to prevent a separation, and who is inspired by the men and women described in the biblical text, the Old Testament. Such inspiration has been considered here as a backlash to the real life of women. The idea of a backlash (Faludi, 2001) seems to be an element that easily adheres to the religious culture of Universal Church, allied to the cultural pedagogy taught by The Love School; it characteristically operates as a cyclic cultural policy. And, cyclically, the culture seems to make us live several moments of intense regression both through certain media products and through the reactions of certain political groups imposing their interests. Hence, I believe the contemporary Brazil is living a religious cycle of backlash regarding life and love relationship issues to say the least.
25

Tribologia de um inserto metal-osso maxilar / Tribology of a maxilar jaw metal-bone insert

Sousa, Jo?o Andrade Lopes de 02 May 2016 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-01-12T14:20:00Z No. of bitstreams: 1 JoaoAndradeLopesDeSousa_DISSERT.pdf: 61529909 bytes, checksum: e210522b263ff132558591081dbd66de (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-01-18T14:02:46Z (GMT) No. of bitstreams: 1 JoaoAndradeLopesDeSousa_DISSERT.pdf: 61529909 bytes, checksum: e210522b263ff132558591081dbd66de (MD5) / Made available in DSpace on 2017-01-18T14:02:46Z (GMT). No. of bitstreams: 1 JoaoAndradeLopesDeSousa_DISSERT.pdf: 61529909 bytes, checksum: e210522b263ff132558591081dbd66de (MD5) 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.
26

Vida eterna para os casamentos : a pedagogia evangelizadora da escola do amor da Igreja Universal do Reino de Deus

Bueno, Paulo Fernando Zanardini January 2017 (has links)
Esta dissertação, de abordagem qualitativa, e situada no campo dos Estudos Culturais em Educação, analisou nas falas dos apresentadores de um artefato cultural da televisão, o programa The Love School, os temas mais discutidos por eles. Como primeira técnica da metodologia utilizada, esse recurso gerou a fonte de material empírico registrado no que nominei de caderno de transcrições. Para realizar esta investigação selecionei 24 (vinte e quatro) edições do programa entre o período de novembro de 2014 a abril de 2015. O casamento é o principal tema que orienta a pauta deste programa e faz uma aliança direta com os princípios que fundamentam a Igreja Universal do Reino de Deus. Quanto ao programa The Love School foi possível entender que a Universal desenvolveu uma nova forma de falar de religião fazendo uso de outras linguagens como a linguagem própria da televisão, pois esse novo produto da grade de programação da Record TV, pode ter dado início a uma nova sequencia de programas televangelizadores, que, nas versões mais tradicionais e mais religiosas, parecem monótonos e desinteressantes pelo uso da linguagem comum aos púlpitos das catedrais e pelos horários de exibição cansativos das madrugadas. A categoria da pedagogia cultural, como um conceito caro para o campo da educação, nesse artefato cultural, pode ser percebida com uma outra dinâmica que não apenas a de ensinar modos de ser e de viver, pois demostrou que, conjuntamente a isso, pode também apontar o contraexemplo de outras pedagogias culturais em outros artefatos culturais, dessa vez os do entretenimento comercial. Compreendi essa atuação do conceito nesse objeto pela introdução da cultura religiosa com origem na Igreja criticando a cultura profana de outros produtos da mídia. Essa mesma discursividade molda um modelo de casal que prioriza o casamento acima de qualquer problema, devendo superar o menor dos desafios para impedir uma separação, e que se inspira no homem e na mulher presentes no texto bíblico, no Antigo Testamento, inspiração que é vista no contexto da análise aqui empregada como um retrocesso para a vida real das mulheres. A ideia de retrocesso ou de backlash (Faludi, 2001) parece ser um elemento que adere facilmente à cultura religiosa da Universal, aliando-se à pedagogia cultural ensinada pelo The Love School. O backlash tem como característica operar como uma política cultural em forma de ciclos. Ciclicamente, a cultura parece nos fazer viver muitos momentos de intenso retrocesso (backlash), tanto por meio de determinados produtos da mídia quanto pelas reações de determinados grupos políticos nos impondo seus interesses. Consequentemente, pelas análises que aqui empreendi e por essas características assumidas pela IURD, penso que vivemos no Brasil contemporâneo um ciclo religioso de backlash (retrocesso) para as coisas da vida e para as relações amorosas, para dizer o mínimo. / This qualitative approach master‘s dissertation on Educational Cultural Studies has analyzed the lines of the presenters of a cultural artifact of television, The Love School show, and the subjects most discussed by them. As the first technique of the methodology used, this resource generated the source of empirical material registered in what I named ―The Transcription Notebook‖. For the research, I have selected 24 (twenty four) editions of the show from November, 2014 to April, 2015. Marriage is the central theme of the show‘s agenda which is directly related to the principles underlying the Universal Church of the Kingdom of God. Through The love school show it was possible to realize that the Universal Church has developed a new way of talking about religion, by making use of other languages, such as the proper language of television, since this new product offered by the Record TV channel may have initiated a sequence of new evangelizing shows, which tend to be monotonous and uninteresting in their most traditional and religious versions due to the use of a language common to the cathedrals‘ pulpits as well as the tiresome show times. Such cultural artifact allow us to understand the concept of cultural pedagogy category, dear to the field of education, as a different dynamic that does not only teach ways of being and living, but also show the counterexample of other cultural pedagogies in another cultural artifacts, such as the commercial entertainment. I have understood this concept in such object through the introduction of the religious culture originating in the Church that criticizes the unholy culture of media products. This same discourse frames a standard of couple who prioritize marriage above any problem so as to overcome challenges to prevent a separation, and who is inspired by the men and women described in the biblical text, the Old Testament. Such inspiration has been considered here as a backlash to the real life of women. The idea of a backlash (Faludi, 2001) seems to be an element that easily adheres to the religious culture of Universal Church, allied to the cultural pedagogy taught by The Love School; it characteristically operates as a cyclic cultural policy. And, cyclically, the culture seems to make us live several moments of intense regression both through certain media products and through the reactions of certain political groups imposing their interests. Hence, I believe the contemporary Brazil is living a religious cycle of backlash regarding life and love relationship issues to say the least.
27

"Os assuntos que discutimos são a cara da nossa luta" : um estudo antropológico dos debates feministas em meio às possibilidades de sociabilidade online

Silveira, Natália Alves Cardoso Orlandi January 2013 (has links)
Este trabalho se propõe a analisar a intersecção entre o feminismo e o mundo virtual, a partir da análise qualitativa de um coletivo feminista que abrange uma lista de discussão online e um blog coletivo, denominado Blogueiras Feministas. Partindo do pressuposto de que a internet abre caminhos e novas possibilidades de sociabilidade, pretendendo avaliar o quanto esse aspecto foi aproveitado por este coletivo virtual a partir de suas discussões e produções textuais. Indo de encontro ao ideário propagado no senso comum e em alguns setores de que o feminismo já seria um movimento morto ou relegado ao próprio fracasso, inicia-se a análise a partir de referenciais teóricos feministas que foram encontrados em campo, em especial Susan Faludi e sua conceituação de backlash, abordando a forma como a internet propicia novas formas de enfrentamento a esse retrocesso percebido. Passando, então, para a perspectiva do Sofrimento Social, por meio da Antropologia da Experiência, pretende-se investigar como tal auto atribuição identitária e mobilização política se intercruzam nos meios online e offline, deixando entrever como a violência estrutural de gênero ainda permeia o compartilhamento de experiências; e como de determinada perspectiva inclusiva passa-se à formativa, de novos conhecimentos e formas de reivindicação. Finalizando, com a abordagem de novas pautas que emergem e são assimiladas por esse movimento cuja preocupação com a inclusão se mostra basilar. / This paper aims at analyzing the intersection between the feminist world and the virtual world, through a qualitative analysis of a feminist group that comprises an online discussion list, and a collective blog, called “Blogueiras Feministas”. Starting from the assumption that the internet opens paths and new sociability possibilities, intending to evaluate how much this virtual group took advantage of this aspect through its discussions and text productions. Going against the idea, spread by common sense and by some sectors of society, that feminism is already either dead or relegated to its own failure, the analysis starts from some feminist theoretical references that were found in field, specially Susan Faludi and her conceptualization of backlash, addressing the manner in which the internet allows new forms of facing this perceived throwback. Thereafter, the perspective of the Social Suffering is treated. Through the Antropology of the Experience it is investigated how such identity auto attribution and political mobilization meet in both online and offline environments, allowing a glimpse of how the structural gender violence still permeates the sharing of experiences; and how a certain inclusive perspective gives place to a formative one, of new knowledges and new means of claim. Finally, there is the approach of new agendas that are emerging and that are assimilated by this movement whose concern about inclusion is basic ground.
28

Modélisation de la dynamique des boîtes de vitesses automobiles soumises à des sollicitations acycliques : applications à la prédiction du bruit de grenaille et validation expérimentale

Chauvineau, Guillaume 09 September 2014 (has links)
La boite de vitesses est un des principaux organes d’une automobile et son développement est complexe. De nombreuses contraintes doivent être prises en compte et notamment son comportement acoustique et vibratoire. Cet aspect de la conception est de nos jours assez mal maitrisé et les nuisances acoustiques des boites de vitesses, telle que le bruit de grenaille, sont bien souvent découvertes tardivement. L’objectif de ces travaux était le développement d’un modèle numérique de dynamique des engrenages applicable aux boites de vitesses et permettant de prédire les conditions d’apparition du bruit de grenaille. La modélisation proposée dans cette thèse repose sur une association originale de différentes modélisations et est applicable à la grande majorité des boites de vitesses. Les éléments flexibles tels que les arbres et les carters sont modélisés par la méthode des éléments-finis. Un modèle d’engrenage basé sur le modèle de contact de Kelvin-Voigt est développé. Ce dernier permet la prise en compte des pertes de contact et des chocs sur les flancs avants et arrières. Pour compléter la modélisation, des modèles de pertes mécaniques sont implémentés afin de prendre en compte l’influence des roulements, des paliers lisses, des synchroniseurs et du barbotage des pignons dans l’huile. Le modèle développé, couplé à un indicateur de bruit de grenaille, permet de réaliser des études de sensibilités afin d’identifier les paramètres influents sur le bruit de grenaille mais aussi de comparer les comportements vibratoires de différentes configurations. Pour finir, une campagne d’essais sur une boite de vitesse industrielle est réalisée et des résultats de simulations lui sont confrontés. / The gearbox is an important component of an automobile and its development is complex. Numerous constraints must be taken into account, particularly its noise and vibration behavior. This aspect of the conception is nowadays poorly mastered and the noise pollution of gearboxes, such as the rattle noise, are often discovered late. The aim of this work was the development of a numerical model of gear dynamics adapted to gearboxes’ modelling and allowing to predict the conditions of gear rattle noise appearance. The model proposed in this thesis is based on an original combination of different models and is applicable to the vast majority of gearboxes. Flexible components, such as shafts and housings are modeled by the finite element method. A gear model based on Kelvin-Voigt contact model is developed. It allows to take into account the contact losses and the back side contacts. To complete this model, mechanical loss models are implemented in order to take into account the influence of the bearings, plain bearings, synchronizers and gears’ immersion in oil. This model coupled with a noise indicator allows for sensitivity analyzes to identify influential parameters on the rattle noise but also to compare the dynamic behavior of different configurations. Finally, a test campaign on an industrial gerbox is conducted and simulation results are confronted to measurements.
29

Dynamic torque clutch control for heavy duty vehicles using a backlash size and position observer

Eliasson Godonou, Samuel January 2017 (has links)
This master's thesis investigated the possibility to control the clutch torque in order to better traverse a Scania vehicles powertrain backlash. When traversing a backlash the torque difference between the two gears will at the time of contact excite oscillations in the powertrain, and by controlling the torque these oscillations can be minimized. The master's thesis solves this issue in three major steps. First a Simulink model was created to mimic the actual vehicles powertrain as closely as possible. It was created using mostly Simdriveline components and then validated by comparing simulations to measurements from real drives. After that backlash position and backlash size observers were created in order to estimate them. Using the developed Simulink model these observers could then be evaluated, and the backlash position observer proved to be very precise while the backlash size observer was not as precise but still usable. Finally a control strategy was devised, by using the estimates from the developed observers it was supposed to control the clutch torque in a better way than previously done. The controller was a switching controller that simply used the full engine torque while the backlash was in contact, and a P controller to control the clutch torque while performing a backlash traverse. The controller proved to perform well and was robust to errors in the backlash size. Future work to be done could be to develop a shaft torque observer for use in the already developed observers.
30

New control design and analysis techniques for plants with actuator nonlinearities

Rodríguez Liñán, María Del Carmen January 2013 (has links)
Actuator saturation is ubiquitous in physical plants. In closed-loop systems limits imposed on the actuators may result in degraded performance of the control law and, ultimately, instability of the system. When other non-linearities, such as deadzone, backlash or stiction, are also present in a system’s input, the analysis and design procedures become more involved. The core of this thesis is a new structure based on the right inverse approach for deadzone and backlash, which is extended to linear plants that exhibit a combination of saturation and either deadzone, backlash or stiction, in the actuator. It is shown that, for this type of system, the inclusion of the right inverse nonlinearity results in the linear plant being subject to a new input saturation. Then, one can design standard controllers such as anti-windup or input constrained MPC around this saturation. This simplifies the analysis and design processes, in spite of the presence of complex nonlinearities. The results for deadzone and backlash are extended to stiction by proposing an approximate stiction nonlinearity, and then introducing a right inverse to this approximation. It is demonstrated that the systems studied can be compensated by a standard input constrained MPC which can be solved by a convex quadratic program. Additionally, a simple anti-windup structure is used to demonstrate the applicability of the proposed structure using existing control strategies.

Page generated in 0.0318 seconds