Dynamic analysis of axially moving cables on elastic supports using the Spectral and Finite Element Methods
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Data
2020-07-30
Autores
Nehemy, Gabriella Furlan
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Universidade Estadual Paulista (Unesp)
Resumo
Em muitos equipamentos industriais, os sistemas com movimento axial são utilizados para transmitir potência, transportar material ou em processos de fabricação. Correias de transmissão, fibras têxteis, serras fita, processo de trefilação a frio, cabos de elevador, folhas de papel, bondes de cabos aéreos são alguns exemplos. Nesses sistemas, a velocidade axial desempenha um papel importante na alteração do comportamento dinâmico, induzindo alterações nas frequências naturais e nos modos de vibração, portanto, o principal problema que restringe as aplicações nesses dispositivos é limitar a vibração transversal causada principalmente pela velocidade de movimento axial. Nesta dissertação, diferentes modelos de cabo com movimento axial foram desenvolvidos com suportes simples, base elástica e periodicidade da base elástica utilizando os métodos dos elementos espectrais e elementos finitos. Análises dinâmicas foram executadas a fim de avaliar as influências da velocidade do movimento axial, da base elástica e da periodicidade da base elástica no comportamento dinâmico de cada um dos modelos. A partir dos resultados, observou-se que o aumento da velocidade do movimento axial diminui as frequências de resonância e anti-ressonância. A base elástica aumenta a frequência de ressonância porém não tem influência na frequência de anti-ressonância dos modelos. Para o modelo periódico, quando se aumenta a constante linear elástica da base as regiões de propagação ficam mais estreitas e quando há aumento da velocidade axial, as regiões de propagação ficam menores.
In many industrial equipment, axially moving systems are used for transmitting power, transport material or as manufacturing processes. Power transmission belts, textile fibers, band saws, cold drawing process, elevator cables, paper sheets, aerial cable tramways are some examples. In these systems the axial speed plays an important role in changing the dynamic behavior, inducing changes in natural frequencies and vibration modes, thus the main problem that constrains applications in these devices is limiting the transverse vibration caused primarily by the axial moving speed. In this dissertation, different axially moving cables were modeled with simple supports, elastic foundation and periodic elastic foundation using the Spectral Element Method and the Finite Element Method. Dynamic analyses were performed in order to evaluate the influence of the moving speed, the elastic foundation and the periodicity on the dynamics of each model. It was observed that the increasing speed decreases all the resonance and anti-resonance frequencies. The elastic foundation increases the resonance frequency however it has no influence on the anti-resonance frequency of the models. However, for the periodic systems analyzed, when the elastic linear constant of the base is increased, the propagation frequency range become narrower and when there is an increase in axial velocity, the propagation frequency range become smaller.
In many industrial equipment, axially moving systems are used for transmitting power, transport material or as manufacturing processes. Power transmission belts, textile fibers, band saws, cold drawing process, elevator cables, paper sheets, aerial cable tramways are some examples. In these systems the axial speed plays an important role in changing the dynamic behavior, inducing changes in natural frequencies and vibration modes, thus the main problem that constrains applications in these devices is limiting the transverse vibration caused primarily by the axial moving speed. In this dissertation, different axially moving cables were modeled with simple supports, elastic foundation and periodic elastic foundation using the Spectral Element Method and the Finite Element Method. Dynamic analyses were performed in order to evaluate the influence of the moving speed, the elastic foundation and the periodicity on the dynamics of each model. It was observed that the increasing speed decreases all the resonance and anti-resonance frequencies. The elastic foundation increases the resonance frequency however it has no influence on the anti-resonance frequency of the models. However, for the periodic systems analyzed, when the elastic linear constant of the base is increased, the propagation frequency range become narrower and when there is an increase in axial velocity, the propagation frequency range become smaller.
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Axially moving systems, Elastic foundation, Periodicity, Spectral Element Method, Spectral Element Method, Sistemas com movimento axial, Base elástica, Periodicidade, Método dos Elementos Espectrais, Método dos Elementos Finitos