Avaliação dinâmica de amortecedores por atrito seco para atenuar vibrações de um sistema vibratório

• Ano de defesa: 2014
• Autor(a) principal: Rodriguez, Freddy Alexander Murillo
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Uberlândia; BR; Programa de Pós-graduação em Engenharia Mecânica; Engenharias; UFU
• Palavras-chave em Português: Dissipação de energia vibratória; Amortecedor por atrito; Identificação de parâmetros; Vibração; Amortecimento (Mecânica); Dissipation of vibrational energy; Dry friction damper; Parameter identification; CNPQ::ENGENHARIAS::ENGENHARIA MECANICA
• Link de acesso: https://repositorio.ufu.br/handle/123456789/14951; https://doi.org/10.14393/ufu.di.2014.292

In the present work the effect of a dry friction damper device on the dynamic behavior of vibratory systems is analyzed. Two friction devices are designed consisting of a sphere in contact with a flat steel bar. In the first prototype the normal force on the contact is kept constant. In the second device a piezoelectric actuator is used to vary the intensity of the normal force. An experimental methodology is developed to analyze the dynamic behavior of a vibratory system and to identify the physical properties of the friction damper devices. The mathematical-computational models of the two friction dampers are used to perform simulations with a vibratory system, in order to analyze the influence of the variation of the normal contact force on the behavior of the vibratory system and to evaluate the dissipation of vibrational energy. In the first damper, an experimental methodology is used to identify the behavior of friction force induced on the vibratory system, and also to identify nonlinearities due to friction Frequency response is used to identify the structural frequencies generated by the device, as well the operational band of the damper device with constant normal force. The time domain vibratory system response is used to identify the Coulomb friction model. The second damper is designed by finite element method. Experimental analysis of the device is applied to identify the parameters that define the static and dynamic behavior of the damper with variable normal load, The frequency response is used to identify the structural frequencies generated by the device, as well it s effective operational band.. Another experiment evaluates the effect of the normal contact force variation on the dynamic response of a vibratory structure. The vibratory system response is identified using Coulomb friction models. Finally, numerical simulations are used to evaluate the effect of the normal contact variation, generated by a semi active control, on the vibratory system dynamic behavior. The vibration attenuation and the power demand of the piezoelectric actuator .are evaluated.